SEISMIC EVALUATION OF MASONRY BUILDING CONGLOMERATIONS OF ADJACENT STRUCTURES A Dissertation Submitted in Partial Fulfilment of the Requirements for the Master Degree in Earthquake Engineering By Adam Rush Supervisor(s): Dr GUIDO MAGENES Dr ANDREA PENNA December, 2007 Istituto Universitario di Studi Superiori di Pavia Università degli Studi di Pavia The dissertation entitled “Seismic evaluation of masonry building conglomerations of adjacent structures”, by Adam Rush, has been approved in partial fulfilment of the requirements for the Master Degree in Earthquake Engineering. Guido Magenes 1 …… … Andrea Penna 2………… … ……… …… Abstract ABSTRACT A masonry building conglomeration is a series of masonry buildings in close enough proximity to one another that they will interact during an seismic event. Recent earthquakes have demonstrated that single buildings within a masonry conglomeration, like historic city centres, are susceptible to damage due to the interaction of adjacent buildings. This damage typically occurs in the form of local failures of individual walls and other structural elements, sometimes resulting in collapse of the entire building. Understanding of this behaviour and remediation measures have progressed to the point that with the necessary resources, historic buildings can be strengthened to prevent these local failures. This study is concerned with buildings that tend not to exhibit local failure mechanism during an earthquake and are susceptible to global damage due to building interaction. The goal is to determine which of five major parameters most influence the behaviour of a building due to inter-building interaction. These parameters are: stiffness of the walls, height of the building, mass of the building and stiffness of the diaphragm, type of inter-building connection, and position within a conglomeration. Monotonic pushover analysis is conducted on various combinations of coupled systems and multiple building conglomerations. The results indicate that the relative heights of adjacent buildings and the type of inter-building connection are the most important parameters to consider for future studies. Keywords: masonry conglomeration; pounding; global response; Tremuri i Index TABLE OF CONTENTS Page ABSTRACT ............................................................................................................................................i TABLE OF CONTENTS .......................................................................................................................ii LIST OF FIGURES ................................................................................................................................ v LIST OF TABLES...............................................................................................................................viii LIST OF SYMBOLS.............................................................................................................................ix 1. INTRODUCTION .............................................................................................................................1 1.1 Background ................................................................................................................................1 1.2 Interaction Connection Types ....................................................................................................4 1.2.1 Pounding Connection.......................................................................................................4 1.2.2 Full Connection................................................................................................................5 1.3 Position within a Row Conglomeration .....................................................................................6 1.3.1 Presence of Heavier Buildings within a Conglomeration ................................................6 2. SEISMIC VULNERABILITY STUDY OF BUILDING CONGLOMERATIONS.........................7 2.1 Parametric Study Program .........................................................................................................7 2.2 Modelling...................................................................................................................................9 2.2.1 Macro-element modelling................................................................................................9 2.2.2 In-plane wall model .......................................................................................................10 2.2.3 3D model........................................................................................................................11 3. SINGLE BUILDINGS ....................................................................................................................12 3.1 System Description ..................................................................................................................12 3.2 Results......................................................................................................................................14 3.2.1 Monotonic Pushover Results .........................................................................................15 3.2.2 Cyclic Pushover Results ................................................................................................16 3.3 Discussion ................................................................................................................................17 ii Index 4. COUPLED SYSTEM ......................................................................................................................18 4.1 Analysis ...................................................................................................................................18 4.2 Individual Building Results .....................................................................................................18 4.2.1 One Storey, Flexible Wall and Wood Floors Building ..................................................20 4.2.2 One Storey, Flexible Wall and Concrete Floors Building .............................................21 4.2.3 Two Stories, Flexible Wall and Wood Floors Building.................................................22 4.2.4 Two Stories, Flexible Wall and Concrete Floors Building ............................................24 4.2.5 Three Stories, Flexible Wall and Wood Floors Building...............................................25 4.2.6 Three Stories, Flexible Wall and Concrete Floors Building ..........................................26 4.2.7 Four Stories, Flexible Wall and Wood Floors Building ................................................28 4.2.8 Four Stories, Flexible Wall and Concrete Floors Building............................................29 4.2.9 One Storey, Rigid Wall and Wood Floors Building ......................................................30 4.2.10One Storey, Rigid Wall and Concrete Floors Building..................................................32 4.2.11Two Stories, Rigid Wall and Wood Floors Building.....................................................33 4.2.12Two Stories, Rigid Wall and Concrete Floors Building ................................................34 4.2.13Three Stories, Rigid Wall and Wood Floors Building...................................................36 4.2.14Three Stories, Rigid Wall and Concrete Floors Building ..............................................37 4.2.15Four Stories, Rigid Wall and Wood Floors Building.....................................................38 4.2.16Four Stories, Rigid Wall and Concrete Floors Building ................................................39 4.3 Discussion ................................................................................................................................41 4.3.1 Pounding Connection.....................................................................................................41 4.3.2 Full Connection..............................................................................................................42 5. CONGLOMERATIONS .................................................................................................................45 5.1 Analysis ...................................................................................................................................45 5.2 Monotonic Pushover Results ...................................................................................................46 5.2.1 Three building conglomerations ....................................................................................47 5.2.2 Six building conglomerations ........................................................................................51 5.2.3 Nine building conglomerations......................................................................................53 5.2.4 Pounding connections, no concrete floor buildings .......................................................55 5.2.5 Full connections, no concrete floor buildings ................................................................55 5.2.6 Pounding connection, external concrete floor building .................................................57 5.2.7 Full connection, external concrete floor building ..........................................................57 5.2.8 Pounding connection, internal concrete floor building ..................................................58 5.2.9 Full connection, internal concrete floor building...........................................................59 5.3 Discussion ................................................................................................................................59 6. CONLCUSIONS .............................................................................................................................60 iii Index 6.1 Further Study ...........................................................................................................................60 REFERENCES .....................................................................................................................................61 APPENDIX A – SINGLE BUILDING RESULTS ............................................................................. A1 A.1 Monotonic Pushover Results ..................................................................................................A1 A.1.1 Height............................................................................................................................ A1 A.1.2 Wall and floor stiffness................................................................................................. A7 A.2 Cyclic Pushover Results .......................................................................................................A12 APPENDIX B – COUPLED SYSTEM COMBINATIONS ............................................................... B1 APPENDIX C – ROW CONGLOMERATION COMBINATIONS .................................................. C1 iv Index LIST OF FIGURES Page Figure 1.1. Arial view of a historic building conglomeration in Italy ........................................2 Figure 1.2. Typical local failure mechanisms [D’Ayala et al., 1996] ........................................3 Figure 1.3. Examples of global masonry building damage due to an earthquake ......................4 Figure 1.4. Examples of pounding and full inter-building connections .....................................5 Figure 2.1. Macro-element panel [Galasco et al., 2004] ..........................................................10 Figure 2.2. Wall construction using macro-elements ...............................................................11 Figure 3.1. General plan view of prototype building used in analysis – X-axis defined for the length of building and Y-axis defined for the width of the building ..........................12 Figure 3.2. Elevation view and model of 3 storey tall theoretical building used in analysis ...13 Figure 3.3. Single building models ...........................................................................................14 Figure 3.4. Monotonic pushover curves: rigid walls & concrete floors ...................................15 Figure 3.5. Monotonic pushover curves: 3 storey buildings.....................................................15 Figure 3.6. Effect of wood floors and the lack of a fully rigid diaphragm ...............................16 Figure 3.7. Cyclic pushover curves for 3 storey buildings .......................................................17 Figure 4.1. Example: L12 H2 F1 – L24 H4 F1 – C2 – B2 .......................................................19 Figure 4.2. One storey, flexible wall and wood floors building ...............................................21 Figure 4.3. One storey, flexible wall and concrete floors building...........................................22 Figure 4.4. Two stories, flexible wall and wood floors building..............................................23 Figure 4.5. Two stories, flexible wall and wood floors building..............................................24 Figure 4.6. Two stories, flexible wall and concrete floors building .........................................25 Figure 4.7. Three stories, flexible wall and wood floors building............................................26 Figure 4.8. Three stories, flexible wall and concrete floors building .......................................28 Figure 4.9. Four stories, flexible wall and wood floors building..............................................29 v Index Figure 4.10. Four stories, flexible wall and concrete floors building .......................................30 Figure 4.11. One storey, rigid wall and wood floors building..................................................31 Figure 4.12. One storey, rigid wall and concrete floors building .............................................33 Figure 4.13. Two stories, rigid wall and wood floors building ................................................34 Figure 4.14. Two stories, rigid wall and concrete floors building............................................35 Figure 4.15. Three stories, rigid wall and wood floors building...............................................37 Figure 4.16. Three stories, rigid wall and concrete floors building..........................................38 Figure 4.17. Four stories, rigid wall and wood floors building ................................................39 Figure 4.18. Four stories, rigid wall and concrete floors building............................................40 Figure 4.19. Pounding connection ............................................................................................42 Figure 4.20. Full connection .....................................................................................................43 Figure 4.21. Three stories, rigid walls buildings for Row Conglomerations............................44 Figure 5.1. Example: 3 * L24 H3 F1 – C1 – B2 w/ external F2...............................................47 Figure 5.2. 3 building conglomerations results.........................................................................47 Figure 5.3. 3 Building conglomeration models ........................................................................48 Figure 5.4. 3 building conglomeration models .........................................................................49 Figure 5.5. Comparison of wood vs concrete floors.................................................................50 Figure 5.6. 6 building conglomerations results.........................................................................51 Figure 5.7. 6 building conglomeration models .........................................................................52 Figure 5.8. 6 building conglomeration models .........................................................................53 Figure 5.9. 9 building conglomerations results.........................................................................54 Figure 5.10. 9 building conglomeration models .......................................................................54 Figure 5.11. 9 building conglomeration models .......................................................................55 Figure 5.12. Pounding connections, no concrete floor buildings .............................................55 Figure 5.13. Full connections, no concrete floor buildings ......................................................56 Figure 5.14. Model....................................................................................................................56 Figure 5.15. Full connections, no concrete floor buildings without unusual pushover curves.57 Figure 5.16. Pounding connection, external concrete floor building........................................57 Figure 5.17. Full connection, external concrete floor building.................................................58 Figure 5.18. Pounding connection, internal concrete floor building ........................................58 Figure 5.19. Full connection, internal concrete floor building .................................................59 Figure A.1. Monotonic pushover curves: flexible walls & wood floors .................................A3 Figure A.2. Constants: flexible walls & wood floors ..............................................................A3 vi Index Figure A.3. Monotonic pushover curves: flexible walls & concrete floors.............................A4 Figure A.4. Constants: flexible walls & concrete floors..........................................................A4 Figure A.5. Monotonic pushover curves: rigid walls & wood floors ......................................A5 Figure A.6. Constants: rigid walls & wood floors ...................................................................A5 Figure A.7. Monotonic pushover curves: rigid walls & concrete floors .................................A6 Figure A.8. Constants: rigid walls & concrete floors ..............................................................A6 Figure A.9. Monotonic pushover curves: 1 storey buildings...................................................A8 Figure A.10. Constant: 1 storey buildings ...............................................................................A8 Figure A.11. Monotonic pushover curves: 2 storey buildings.................................................A9 Figure A.12. Constant: 2 storey buildings ...............................................................................A9 Figure A.13. Monotonic pushover curves: 3 storey buildings...............................................A10 Figure A.14. Constant: 3 storey buildings .............................................................................A10 Figure A.15. Monotonic pushover curves: 4 storey buildings...............................................A11 Figure A.16. Constant: 4 storey buildings .............................................................................A11 Figure A.17. Cyclic pushover curves for 1 storey buildings .................................................A12 Figure A.18. Cyclic pushover curves for 2 storey buildings .................................................A13 Figure A.19. Cyclic pushover curves for 3 storey buildings .................................................A14 Figure A.20. Cyclic pushover curves for 4 storey buildings .................................................A14 vii Index LIST OF TABLES Page Table 2.1. Wall dimensional .......................................................................................................8 Table 2.2. Interstorey heights......................................................................................................8 Table 2.3. Floor descriptions ......................................................................................................8 Table 3.1. Wall composition.....................................................................................................13 Table 4.1. Notation description for navigating result files .......................................................19 Table 5.1. Notation description for navigating result files .......................................................46 Table A.1. Legend for height comparison ...............................................................................A2 Table A.2. Legend for wall and floor comparison...................................................................A7 Table B.1. Analysis coupled systems ......................................................................................B1 Table C.1. Conglomeration list................................................................................................C1 viii Index LIST OF SYMBOLS Notation L12 L24 H1 H2 H3 H4 F1 F2 C1 C2 B1 B2 B4 B5 Description Length of in-plane wall = 12 m Length of in-plane wall = 24 m Number of stories = 1 with individual storey heights matching previous table Number of stories = 2 with individual storey heights matching previous table Number of stories = 3 with individual storey heights matching previous table Number of stories = 4 with individual storey heights matching previous table Floor composition = wood Floor composition = concrete Inter-building connection type = pounding Inter-building connection type = full connection Building 1 in a coupled or row conglomeration system Building 2 in a coupled or row conglomeration system Building 4 in a coupled or row conglomeration system Building 5 in a coupled or row conglomeration system 9 Chapter 1. Introduction 1. INTRODUCTION A masonry building conglomeration is a series of masonry buildings in close enough proximity to one another that they will interact during an seismic event. Recent earthquakes have demonstrated that single buildings within a masonry conglomeration, like historic city centres, are susceptible to damage due to the interaction of adjacent buildings. This interaction causes damage through the transfer of inertial forces either by pounding of adjacent buildings or through coupling effects in the seismic response. In some instances, damage due to conglomerations can cause a premature failure of the building. Previous studies of these conglomerations focus on how pounding between adjacent buildings trigger local failure mechanisms. Out-of-plane bending of walls is a common local failure mechanism of concern throughout these studies. These local failures are common among poorly constructed buildings with weak connections between the walls and floors and poor masonry materials. Fewer studies focus on the impact that these systems have on the global response of a building. Those that do address these issues tend to telly on elastic models to draw conclusions. Since many historic city centres are comprised of masonry buildings, inelastic models are essential to describe the response of a building to an earthquake. This study attempts to determine some simple relationships for buildings within a conglomeration in order to describe the interaction effects within the conglomeration during an earthquake. The purpose of this study is to determine the role that building interaction should play in evaluating the seismic vulnerability of historic city centres. 1.1 Background A typical historic city centre, like many found throughout Europe, consist of mostly masonry buildings of various shapes, sizes, age, quality and style. The complexity of urban centres is massive and continues to change today through renovations and continuous construction. As the 1997 earthquake of Umbria-Marche demonstrated, these historic city centres are susceptible to lots of damage. Some of the damage occurred due to the interaction between buildings. Similarly, the Mexico City earthquake of 1985 caused lots of destruction due to pounding of adjacent buildings. Since that earthquake, many researchers have focused considerable effort in studying the effects of pounding within city centres. The focus of pounding research has been to determine safe distances between structures which adequately prevent pounding from occurring. Where these safe distances cannot be enforced, various techniques are considered 1 Chapter 1. Introduction to reduce the effects of pounding. Most of the research in this field, however, has tended to focus on elastic-homogenous systems, like steel, which do not make up the majority of buildings in historic city centres. Figure 1.1. Arial view of a historic building conglomeration in Italy Previous studies which focus on the vulnerability of historic city centres focus primarily on the development of local failure mechanisms within buildings. These failures are the most common type for masonry buildings during an earthquake. They are usually caused by flaws within a building and can lead to a progressive collapse of the entire structure. Typically, however, the entire building does not collapse and only part of the building is damaged. Figure 1.2 shows common types of local failures. Most local failures of primary interest to researchers are caused by out-of-plane bending of walls or separation of wall components for multi-leaf masonry wall systems. Local failures tend to be building specific and there are procedures already in place to address these issues. 2 Chapter 1. Introduction Figure 1.2. Typical local failure mechanisms [D’Ayala et al., 1996] Modelling of these failures require specialized models for each building condition and only require looking at individual building components. The entire building does not need to be modelled in order to capture local failure mechanisms. The purpose of this study is to determine what role building interaction plays on assessing the vulnerability of a historic city centre. If local failure mechanism can be addressed, then the goal of this study is to determine the levels of increase demands building interaction places on a structure and which factors influence this demand. The purpose is not to address local failure mechanisms caused by adjacent buildings, but rather to focus on the global response of a building. 3 Chapter 1. Introduction Shear Sliding Rocking Pounding Figure 1.3. Examples of global masonry building damage due to an earthquake This study attempts to model the global behaviour of buildings and capture their interaction between one another. The goal is to gain a better understanding of how this global building interaction influences the response of each building. failure mechanisms like shear sliding and rocking for piers, as seen in Figure 1.3, are of particular interest because they are failure mechanisms related to the global response of a building. To capture these behaviours and the changes of behaviour due to building interaction within a conglomeration, a macro-element modelling program was used which will allow for average inelastic behaviour of masonry elements. This modelling system is described in greater detail in the following chapter. 1.2 Interaction Connection Types Much like the historic centres themselves, the interactions between adjacent buildings is a complex problem with many variables. Distance between buildings, material properties of the façade systems, and relative stiffness of the two buildings are a few of the factors which influence the inter-building interaction. A proper representation of the inter-building connection is needed before being able to capture the global response. To simplify the many different conditions found within a historic centre, two types of inter-building connections are considered. 1.2.1 Pounding Connection The first inter-building connection considered is the pounding connection, which represents buildings physically separated. Inertial forces between these buildings are transferred when 4 Chapter 1. Introduction the gap between them closes and the buildings come into contact. This connection models the response of independent buildings and allows for a transfer of forces when the buildings make contact under dynamic loading while still enabling the buildings to separate freely when moving in opposite directions. This connection is achieved by using a zero tension element that only transfers compressive loads. This zero tension elements share the same compression strength of masonry and thus included crushing of masonry between the piers when it occurs. The models shown in Figure 1.4 provide examples of the typical behaviour of the pounding connection. As can clearly been seen in the figure, the taller and thus more flexible building pulls away from the shorter and more rigid building in one direction and then transfers its inertial forces through the zero tension links in the other direction. In many cases, taller and more flexible buildings tended to develop a soft storey directly above the shorter and more rigid building when pounding against it. 1.2.2 Full Connection The second inter-building connection is the full connection. It represents the conditions when adjacent buildings are in complete contact and even share a load bearing wall between them. This connection is modelled by a single rigid node shard between two adjacent piers on either side of the shared bearing wall. Figure 1.4 clearly shows the two smaller piers sharing a rigid node between the two buildings. The result of this connection is that the buildings tended to act more like a single structure than individual buildings. In order to maintain similar inertial properties for comparison purposes between the two systems, the common wall has double the normal wall thickness of the other walls within the building. Pounding Connections Full Connections Figure 1.4. Examples of pounding and full inter-building connections 5 Chapter 1. Introduction 1.3 Position within a Row Conglomeration Another important factor to consider is the effect of building position within a conglomeration on the interaction between the buildings and its own response. In theory, buildings in the centre of a row conglomeration should be better shielded from increased seismic demands. This is because the demands would be distributed between the buildings surrounding it. The buildings on the end of a conglomeration, however, experience increased demands due to a build-up of inertial forces throughout the conglomeration and ending with the final building. Thus some of the inertial forces otherwise resisted by previous buildings are now transferred to the final one on the end. The purpose of this study is to determine how important the building’s position is in evaluating the increase of demands it will see and the increase in seismic vulnerability it should have. 1.3.1 Presence of Heavier Buildings within a Conglomeration When historic buildings are updated, those updates may consist of replacing the existing wooden floors with new concrete floors. These floors increase the mass of the building. The increased mass leads to increased seismic demand on the building part of which is transferred to adjacent buildings within a conglomeration. This could have an unintentional detrimental effect on the response of the conglomeration as a whole. The goal is to determine whether additional study is required for renovation projects because of this effect. 6 Chapter 2. Seismic Vulnerability Study of Building Conglomerations 2. SEISMIC VULNERABILITY STUDY OF BUILDING CONGLOMERATIONS The purpose of this study is to determine the role that building interaction should play in evaluating the seismic vulnerability of historic city centres. To that end, this study evaluates a set of parameters to determine which create the most detrimental effects due to building interaction. Monotonic pushover analysis is conducted to characterize the response of the buildings and provide a basis for comparison. 2.1 Parametric Study Program A series of theoretical, but realistic, buildings are used in order to draw comparisons between various parameters. The reasoning behind the theoretical buildings is to study the effects of building interaction while eliminating typical vulnerability parameters found in masonry buildings. The goal is to observe global behaviour of buildings. To this end, all of the theoretical buildings share acceptable parameters to ensure a global building response. The masonry material uses typical properties found for clay brick masonry and the material is considered of good quality. Each building uses the same masonry for the models. The walls are thick enough and sufficiently attached to the floor to ensure out-of-plane stability and structural redundancy. The roofs are flat, so no additional horizontal thrusts are present. The plans are very regular, as seen in Figure 3.1. This eliminates torsional effects and stress concentrations. Diaphragm action was an important parameter to keep in the study and thus two types of floor systems were used with one being rigid and the other fairly flexible. These vulnerability parameters are more critical than building interaction effects because if they are inadequate, then they tend to cause the building to fail regardless of its interaction with adjacent buildings. For this reason, the theoretical buildings are required to be stable in order to observe the interaction effects. The purpose of this study is to determine if otherwise stable buildings are vulnerable to severe earthquake damage due to the increase seismic demands from building interactions. Several parameters are considered in evaluating the effects of building interaction on stable buildings. These parameters are: Stiffness of the building Height of the building Mass of the building and stiffness of the diaphragm 7 Chapter 2. Seismic Vulnerability Study of Building Conglomerations Type of inter-building connection (Pounding or Full) Position within a conglomeration The last two parameters are discussed in greater detail in the previous chapter. These parameters are directly correlated with the building interaction. The other parameters are related to the physical properties of the buildings themselves. The total length of the building is varied in order to create flexible and rigid structures. Buildings were either 12 m or 24 m long and 12 m wide. The same internal wall configuration was kept but scaled to meet the overall dimensions of the different buildings. The different length walls are used to create flexible and rigid building systems. The shorter walls tend to be more flexible and are governed by a rocking mechanism while the longer walls tend to b more rigid and are governed by a shear sliding mechanism. The height and number of stories for each building were also varied. Buildings ranging from 1 to 4 stories tall are considered for this study because this range encompasses the typical number of stories for load bearing masonry buildings in historic city centres. Changing the height of the buildings changes the base shear, the stiffness and the natural period of the building, all of which are important characteristics in determining building response. The material for the floors is modelled as either wood or concrete to capture the differences between stiffer diaphragms and buildings masses. These parameters are listed in Tables 2.1 to 2.3 in greater detail. Table 2.1. Wall dimensional Length, L 12 m 24 m Stiffness Flexible Rigid Table 2.2. Interstorey heights Storey Number 1 Storey Building 3m 2 Storey Building 3m 3m 3 Storey Building 3m 3m 2.5 m * 4 Storey Building 1 3m 2 3m 3 3m 4 2.5 m * Interstorey height increased to 3 m for 3 storey to 4 storey building comparison to make model creation easier Table 2.3. Floor descriptions Flexibility Rigid Flexible Type Concrete Wood 8 Chapter 2. Seismic Vulnerability Study of Building Conglomerations The total number of different individual buildings generated from varying each of the individual building parameters is 16. The total number of coupled systems generated by combining all 16 individual buildings to each other including both types of connections is 512. The total number of 3 building row conglomerations generated by combining all 16 individual buildings in every possible combination of 3 buildings including both types of connections is 16,384. Due to the large number of computations, only monotonic pushover analysis is conducted. The final number of coupled system and row conglomerations models is also reduced because of the results from the single building modelling. A list of coupled systems and row conglomerations are provided within their respective chapters. 2.2 Modelling Previous studies concerning the interaction of adjacent buildings focused their attention primarily on the elastic response of the coupled systems. They also refrain from expanding their findings to a series of buildings as found in conglomerations. There are studies concerned with predicting damage in a historical city centre. These focused on typical local failure mechanism observed in damage centres. Though useful information, they neglected to describe the interaction of building conglomerations to produce such failures. The purpose of this study is to address the shortfalls of previous studies, namely capturing the nonlinear changes in building behaviour under the influence of adjacent structures. The focus in this project is not to capture the local mechanisms of wall behaviour but to focus on the average behaviour and global response of a building. The construction of macro-elements allows for the broad and accurate comparisons between building behaviours without highly detailed analysis. Nonlinear analysis is crucial to understanding the behaviour of masonry buildings during an earthquake. For this reason, pushover analysis was conducted in this study. It was used to determine the overall building characteristics and provide a simple system for comparing the different buildings and interactions. A modified method of pushover analysis allowed the use of macroelements. The procedure, modified with an effective algorithm, transformed the problem of pushing a structure maintaining constant ratios between the applied forces into an equivalent incremental static analysis with one degree of freedom displacement response control node [Galasco et al., 2004]. A triangular distribution was used as the distribution of forces throughout the structure. Figure 3.3 shows the models considered for the single building case. Failure for monotonic loading is considered when a building reached 80% of maximum capacity. 2.2.1 Macro-element modelling Through the use of modelling techniques representing the behaviour of masonry walls in the form of macro-elements, the nonlinear behaviour of masonry building conglomerations can be approximated with relatively little computing power. This modeling system permits the representation of two main in-plane masonry failure modes, with a limited number of degrees of freedom. These modes, depicted based on mechanical assumptions, are bending-rocking and shear-sliding mechanism including friction. Using internal variables, the macro-element takes into account the effect of the limited compressive strength of masonry. The limited crushing strength of masonry is typically developed in the bending-rocking mechanism 9 Chapter 2. Seismic Vulnerability Study of Building Conglomerations through a toe crushing effect. This effect is modeled by means of phenomenological nonlinear constitutive law with stiffness deterioration in compression. The model also considers the shear-sliding damage evolution, which controls the strength deterioration and the stiffness degradation of the masonry panel in shear [Galasco et al., 2004]. The macro-element model is a macroscopic representation of a continuous model in which the parameters are directly correlated to the mechanical properties of the masonry elements. The macro-element parameters should be considered as representative of an average behaviour of the masonry panel. The macro-element is defined by six material parameters: the shear modulus, the axial stiffness, the shear strength of masonry, a non-dimensional coefficient that controls the inelastic deformation, the global friction coefficient and a factor that controls the softening phase [Galasco et al., 2004]. The macro-element panel is divided into 3 substructures as shown in Figure 2.#. the bending and axial effects are concentrated in the two outer substructure, inferior 1 and superior 3. The shear-deformations are centered within the central substructure. This layer does not contain any evidence of axial or bending deformations. A complete 2D kinematic model should take into account the three degrees of freedom for each node “i” and “j” on the extremities: axial displacement, horizontal displacement and rotation. There are two degrees of freedom for the central zone: axial displacement δ and rotation φ (Fig 2.#) [Galasco et al., 2004]. Figure 2.5. Macro-element panel [Galasco et al., 2004] 2.2.2 In-plane wall model A frame representation of the in-plane behaviour of masonry walls is adopted utilizing macroelements for the various frame members as seen in Figure 2.2. Each wall of the building is subdivided into piers and lintels connected by rigid nodes. The development of the piers is described above and the lintels are simply 2-node macro-elements. Earthquake damage observation shows that cracks rarely appear in the rigid nodes of the wall and because of this, the deformation of these regions is assumed to be negligible relative to the macro-element 10 Chapter 2. Seismic Vulnerability Study of Building Conglomerations non-linear deformations governing the seismic response. Rigid end offsets are used to transfer static and kinematic variables between element ends and nodes. Pretension tie rods are also included in the model as non-compressive elements. Node Lintel Pier Figure 2.6. Wall construction using macro-elements 2.2.3 3D model The 3-dimensional masonry buildings are created by joining the in-plane masonry wall models together. Since the macro-elements only consider in-plane behaviour the floor elements distribute the horizontal actions to the walls. This distribution of actions depends upon local flexural behaviour of the floors and the walls. The out-of-plane response of the walls is not computed because they are considered negligible with respect to the global building response, which is governed by their in-plane behaviour. This global response is possible only if vertical and horizontal elements are properly connected. Pretension rods are used to tie-in the walls to the floors in order to properly connect all of the elements. The 3D nodes connecting different walls in corners and intersections need to have 5 d.o.f. in the global coordinate system (uX, uY, uZ, rotX, rotY): the rotational degree of freedom around vertical Z axis can be neglected because of the membrane behaviour adopted for walls and floors. The floor elements are modeled as orthotropic membrane finite elements identified Young and shear moduli in each principle direction, and Poisson ratio. The principle directions align with the wall connections to the floors, which are connected by means of stringcourses and tie-rods. The in-plane floor shear stiffness governs the horizontal action distribution between the different walls. This solution permits the implementation of static analyses with 3 components of acceleration along the 3 principal directions and 3D dynamic analyses with 3 simultaneous input components, too [Guida Tremuri, 2006] 11 Chapter 3. Single Building 3. SINGLE BUILDINGS Before a detailed comparison of building interaction can occur, an understanding of the behaviour of the individual buildings is required. The following section provides the results of monotonic and cyclic pushover analyzes for single masonry buildings. These results provide the foundation for comparisons made in subsequent chapters. 3.1 System Description The theoretical building used consists of eight equally sized rooms in a 2 by 4 unit configuration, each with one window, except for the corner rooms which have two windows. Figure 3.1 below shows a building plan. Buildings were coupled along the longitudinal axis and the width of the building was kept constant at 12 m for simplicity. Figure 3.7. General plan view of prototype building used in analysis – X-axis defined for the length of building and Y-axis defined for the width of the building Tie rods were used in the theoretical building because the focus of this study is on in-plane behaviour of buildings. The tie rods reduce the importance of analyzing out-of-plane behaviour of masonry buildings. Only in-plane behaviour was considered because it controls 12 Chapter 3. Single Building the global response of a building. Interaction with surrounding buildings effects the global characteristics of a building. Local failures are also caused by building interaction, especially pounding. These issues though are not considered in this study because they are highly dependent on the individual building and are difficult to generalize in a large model. Elevation of 3 storey building with dimensions Model of 3 story building Figure 3.8. Elevation view and model of 3 storey tall theoretical building used in analysis Table 3.4. Wall composition Properties Name Elastic Modulus Shear Modulus Specific Weight Compressive or Tensile Strength Shear Strength Thickness / Diameter Pre-Tensioned Masonry Brick 1800 300 18 180 6 40 Tie Rods Fe360 206000 78400 78.5 Units N/mm2 N/mm2 kN/m3 235 N/cm2 30 2000 N/cm2 cm daN 13 Chapter 3. Single Building 3.2 Results As stated earlier, the purpose of this chapter is to determine the pushover characteristics of each of the theoretical buildings to use for comparison purposes later. Below are pictures of walls from the individual buildings used in the study. These walls resist the lateral forces produced from the pushover analyzes. The following comparisons are brief to provide a general overview of the influences on the different building parameters on the response of the buildings themselves. A more in depth discussion of individual building characteristics can be found in Appendix A. 1 story, 12 m 1 storey, 24 m 2 story, 12 m 2 storey, 24 m 3 story, 12 m 3 storey, 24 m 4 story, 12 m 4 storey, 24 m Figure 3.9. Single building models 14 Chapter 3. Single Building 3.2.1 Monotonic Pushover Results In general, the individual buildings perform as expected. The shortest buildings reach the highest levels of acceleration and the tallest have the largest displacements. Buildings with concrete floors tend to have lower levels of acceleration as do buildings with flexible walls. A few exceptions exist and are discussed in Appendix A in greater detail. 1.5 1.0 1 Storey 3 Stories Acceleration (g) 0.5 2 Stories 0.0 0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 -0.5 4 Stories -1.0 -1.5 Displacement (cm) Figure 3.10. Monotonic pushover curves: rigid walls & concrete floors Monotonic Pushover Curves 0.6 Flexible walls, 0.4 Wood floors Flexible walls, Rigid walls, Wood floors Acceleration (g) Concrete floors 0.2 0.0 0.00 1.00 2.00 3.00 4.00 5.00 6.00 -0.2 Rigid walls, Concrete floors -0.4 -0.6 Displace ment (cm) Figure 3.11. Monotonic pushover curves: 3 storey buildings One important observation to note is that buildings with wood floors tend to have larger displacements than those with concrete. The reason is because of weak diaphragm action. This causes most of the load to be concentrated at the interior wall which then fails first and brings the exterior walls with it. This weak diaphragm action remains in the study because of the importance of properly representing historical buildings. A concentration of inertial forces 15 Chapter 3. Single Building or the inability to properly distribute them between the available walls causes the buildings to be weaker than they would be otherwise. Figure 3.6 shows the three parallel lateral resisting walls just before failure for buildings with wood floors. As can be clearly seen in this figure, the interior wall fails first and causes the exterior ones to fail afterwards. Plan view of final displaced shape from monotonic pushover analysis Exterior wall Interior wall Exterior wall Figure 3.12. Effect of wood floors and the lack of a fully rigid diaphragm 3.2.2 Cyclic Pushover Results A general pattern is noticeable in the results for cyclic pushover analysis. For the flexible wall buildings, the hysteretic loops tend to be narrower than for the rigid wall buildings. This means that the energy dissipation was also less for these buildings. This makes sense because the flexible buildings with shorter walls tend to exhibit the rocking mechanism and toe crushing effect which dissipates less energy than the shear sliding mechanism. The longer, more rigid wall buildings tend to exhibit the shear sliding mechanism leading to larger hysteretic loops. Cyclic pushover analysis is only performed for each of the 16 individual buildings and not for either the coupled or row conglomeration systems. The reason is because this study is only concerned with obtaining a general overview of the importance of building interaction in determining the vulnerability of a city centre. To that end, more parameters are studied and less analysis is done. 16 -8.00 -6.00 -4.00 -2.00 0.30 0.30 0.20 0.20 0.10 0.10 0.00 0.00 2.00 4.00 6.00 8.00 Acceleration (g) Acceleration (g) Chapter 3. Single Building -2.50 -2.00 -1.50 -1.00 -0.50 -0.10 -0.10 -0.20 -0.20 -0.30 0.40 0.40 0.20 0.20 2.00 3.00 4.00 5.00 Acceleration (g) Acceleration (g) 0.60 1.00 2.00 2.50 Flexible walls & Concrete floors 0.60 0.00 0.00 1.50 L12_H3_F2 Flexible walls & Wood floors -1.00 1.00 Displacement (cm) L12_H3_F1 -2.00 0.50 -0.30 Displacement (cm) -3.00 0.00 0.00 -2.00 -1.50 -1.00 -0.50 0.00 0.00 -0.20 -0.20 -0.40 -0.40 -0.60 0.50 1.00 1.50 2.00 -0.60 Displacement (cm) L24_H3_F1 Rigid walls & Wood floors Displacement (cm) L24_H3_F2 Rigid walls & Concrete floors Figure 3.13. Cyclic pushover curves for 3 storey buildings 3.3 Discussion These theoretical buildings will provide a good background for the future coupled systems and conglomeration studies. None exhibit local failure mechanisms and all exhibit good inplane wall behaviour. The range of building parameters covers a realistic range of values typically found within a historic city centre for strictly load bearing masonry buildings. Monotonic pushover curves for the single buildings provide a basis of comparison to study the effects of building interaction on a building’s response. 17 Chapter 4. Coupled System 4. COUPLED SYSTEM The purpose of beginning with the coupled systems is to determine how best to model the interaction between buildings. This goal was achieved by running monotonic pushover analysis on various building pairs and comparing the results with the individual buildings. Two methods for connecting the buildings were developed: a pounding connection where flexible buildings where able to separate from more rigid buildings and a full connection between buildings in which the buildings shared a common load bearing wall. Important interaction groups were determined from the monotonic pushover results and used to focus the remaining analyzes. 4.1 Analysis To set a standard analysis procedure for each coupled system, the most flexible building was used for the control node in both directions. The influence by the choice of the node on the results has not been studied. One drawback to this approach readily visible is that the pushover curve for the rigid buildings in the coupled system may not typically include failure of the building. Thus the maximum displacements of the rigid building are never reached. Running the models in this manner makes sense because once the more flexible building fails, not all of its inertial forces are transferred directly into the more rigid building. The results from the monotonic pushover analysis are arranged in a manner to compare the different parameters discussed in the previous chapter. A discussion of how changing the building parameters affect the behaviour of that building can be found in the previous chapter. This chapter is concerned with how changing the parameters of an adjacent building affect the interaction between the buildings. Therefore all comparisons are made with the single building monotonic pushover results. 4.2 Individual Building Results The results are presented on a building by building basis, highlighting the effects of the coupling on the building’s response in each case. The individual building pushover curve is used as a reference point to discuss the effects of other buildings on the curve. Percentage difference curves are created by taking the difference in acceleration over the average acceleration at various displacements along each curve as a comparison. The original pushover curves are provided next to the percentage difference curves for each building. The percentage difference curves demonstrate the effect of coupling on the response of a building. 18 Chapter 4. Coupled System Each set is arranged to compare 4 different elements. The first two graphs show the effects of the pounding connection. The next two show the effects of the full connection. The third set show the effects of buildings with the same wall length on it. So if the building in question has a 12 m long wall, then the third set of graphs will show the influences from other buildings with the same wall length. The final set shows the influences of buildings with a different wall length. So if the building in question has a 12 m long wall, then the fourth set of graphs will all have 24 m length walled buildings acting on it. For ease in recording each of the different combinations, the following short hand notation was created for naming files and recording results. Table 4.5. Notation description for navigating result files Notation L12 L24 H1 H2 H3 H4 F1 F2 C1 C2 B1 B2 Description Length of in-plane wall = 12 m Length of in-plane wall = 24 m Number of stories = 1 with individual storey heights matching previous table Number of stories = 2 with individual storey heights matching previous table Number of stories = 3 with individual storey heights matching previous table Number of stories = 4 with individual storey heights matching previous table Floor composition = wood Floor composition = concrete Inter-building connection type = pounding Inter-building connection type = full connection Building 1 in a coupled or row conglomeration system Building 2 in a coupled or row conglomeration system Example: L12 H1 F2 – Single building with length = 12 m, 1 storey tall, Concrete floors L12 H2 F1 - L24 H4 F1 - C2 - B2 – Coupled system with first building having a length of 12 m, a height of 2 stories, and wood floors. The second building has a length of 24 m, height of 4 stories and wood floors. The connection between the buildings is a full connection and the data presented is for the second building. Figure 4.14. Example: L12 H2 F1 – L24 H4 F1 – C2 – B2 19 Chapter 4. Coupled System 4.2.1 One Storey, Flexible Wall and Wood Floors Building The following are the coupling results for one storey, flexible wall and wood floor (L12_H1_F1) building. As can be seen clearly, the pounding connection tends to more adversely affect the 1 storey building. In the positive direction, or when the 1 storey building acts on the other building, it reaches failure only on 3 occasions, each of which is with a building of a similar stiffness next to it. The other times it remains in the elastic range while the more flexible building reaches failure. As for the full connection, the 1 storey building acts in conjunction with all of the other buildings in the coupled system and thus the strength actually increases. Percent Difference Monotonic Pushover Curves 100% L12_H1_F1 0.8 L12 H1 F1 - L12 H1 F1 - C1 - B1 0.6 L12 H1 F1 - L12 H2 F1 - C1 - B1 0% 0.00 0.10 0.20 0.30 0.40 0.50 0.60 L12 H1 F1 - L12 H3 F1 - C1 - B1 0.4 L12 H1 F1 - L12 H4 F1 - C1 - B1 0.2 L12 H1 F1 - L24 H1 F1 - C1 - B1 -50% L12 H1 F1 - L24 H2 F1 - C1 - B1 Acceleration (g) Percent Difference in Acceleration 50% 0.0 0.00 ……………………… 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 -0.2 -100% L12 H1 F1 - L24 H3 F1 - C1 - B1 -0.4 L12 H1 F1 - L24 H4 F1 - C1 - B1 -150% -0.6 -0.8 -200% Displacement (cm) Displacement (cm) Percent Difference Monotonic Pushover Curves 80% L12_H1_F1 1.0 L12 H1 F1 - L12 H1 F1 - C2 - B1 0.8 60% L12 H1 F1 - L12 H2 F1 - C2 - B1 0.4 L12 H1 F1 - L12 H4 F1 - C2 - B1 20% L12 H1 F1 - L24 H1 F1 - C2 - B1 0% 0.00 L12 H1 F1 - L24 H2 F1 - C2 - B1 0.05 0.10 0.15 0.20 0.25 0.30 0.35 L12 H1 F1 - L24 H3 F1 - C2 - B1 -20% L12 H1 F1 - L24 H4 F1 - C2 - B1 Acceleration (g) Percent Difference in Acceleration 0.6 L12 H1 F1 - L12 H3 F1 - C2 - B1 40% 0.2 0.0 0.00 ……………………… 0.10 0.20 0.30 0.40 0.50 0.60 0.70 0.80 0.90 1.00 -0.2 -0.4 -0.6 -40% -0.8 -1.0 -60% Displaceme nt (cm) Displacement (cm) 20 Chapter 4. Coupled System Percent Difference Monotonic Pushover Curves 100% L12_H1_F1 1.0 L12 H1 F1 - L12 H1 F1 - C1 - B1 0.8 L12 H1 F1 - L12 H2 F1 - C1 - B1 50% 0.4 0% 0.00 0.10 0.20 0.30 0.40 0.50 0.60 0.70 L12 H1 F1 - L12 H4 F1 - C1 - B1 L12 H1 F1 - L12 H1 F1 - C2 - B1 -50% L12 H1 F1 - L12 H2 F1 - C2 - B1 -100% Acceleration (g) Percent Difference in Acceleration 0.6 L12 H1 F1 - L12 H3 F1 - C1 - B1 L12 H1 F1 - L12 H3 F1 - C2 - B1 0.2 0.0 0.00 0.10 0.20 0.30 0.40 0.50 0.60 0.70 0.80 0.90 -0.2 -0.4 L12 H1 F1 - L12 H4 F1 - C2 - B1 -0.6 -150% -0.8 -200% -1.0 Displacement (cm) Displacement (cm) Percent Difference Monotonic Pushover Curves 100% L12_H1_F1 1.0 L12 H1 F1 - L24 H1 F1 - C1 - B1 0.8 L12 H1 F1 - L24 H2 F1 - C1 - B1 50% 0.4 0% 0.00 0.20 0.40 0.60 0.80 1.00 1.20 1.40 L12 H1 F1 - L24 H4 F1 - C1 - B1 L12 H1 F1 - L24 H1 F1 - C2 - B1 -50% L12 H1 F1 - L24 H2 F1 - C2 - B1 -100% Acceleration (g) Percent Difference in Acceleration 0.6 L12 H1 F1 - L24 H3 F1 - C1 - B1 L12 H1 F1 - L24 H3 F1 - C2 - B1 0.2 0.0 0.00 0.20 0.40 0.60 0.80 1.00 1.20 1.40 -0.2 -0.4 L12 H1 F1 - L24 H4 F1 - C2 - B1 -0.6 -150% -0.8 -200% -1.0 Displacement (cm) Displacement (cm) Figure 4.15. One storey, flexible wall and wood floors building 4.2.2 One Storey, Flexible Wall and Concrete Floors Building The following are the coupling results for one storey, flexible wall and wood floor (L12_H1_F2) building. The results indicate that coupling for this building does not have adverse affects. The negative values found in the percent difference curves are present only because the coupled building failed prior to the 1 storey building failing. Therefore the acceleration levels indicated on the graph do not reach the maximum they would have had this building been able to continue its loading after the other on had failed. Percent Difference Monotonic Pushover Curves 150% L12_H1_F2 0.5 L12 H1 F2 - L12 H1 F2 - C1 - B1 0.4 100% L12 H1 F2 - L12 H2 F2 - C1 - B1 0.2 L12 H1 F2 - L12 H4 F2 - C1 - B1 0% 0.00 0.10 0.20 0.30 0.40 -50% 0.50 0.60 0.70 L12 H1 F2 - L24 H1 F2 - C1 - B1 L12 H1 F2 - L24 H2 F2 - C1 - B1 L12 H1 F2 - L24 H3 F2 - C1 - B1 -100% L12 H1 F2 - L24 H4 F2 - C1 - B1 Acceleration (g) Percent Difference in Acceleration 0.3 L12 H1 F2 - L12 H3 F2 - C1 - B1 50% 0.1 0.0 0.00 ……………………… 0.20 0.40 0.60 0.80 1.00 1.20 1.40 -0.1 -0.2 -0.3 -150% -0.4 -200% -0.5 Displacement (cm) Displacement (cm) 21 Chapter 4. Coupled System Percent Difference Monotonic Pushover Curves 100% L12_H1_F2 1.0 L12 H1 F2 - L12 H1 F2 - C2 - B1 90% 0.8 L12 H1 F2 - L12 H2 F2 - C2 - B1 80% 0.4 60% L12 H1 F2 - L12 H4 F2 - C2 - B1 50% L12 H1 F2 - L24 H1 F2 - C2 - B1 40% L12 H1 F2 - L24 H2 F2 - C2 - B1 30% L12 H1 F2 - L24 H3 F2 - C2 - B1 -0.2 20% L12 H1 F2 - L24 H4 F2 - C2 - B1 -0.4 Acceleration (g) Percent Difference in Acceleration 0.6 L12 H1 F2 - L12 H3 F2 - C2 - B1 70% 10% 0% 0.00 0.2 ……………………… 0.0 0.00 0.10 0.20 0.30 0.40 0.50 0.60 0.70 0.80 0.90 1.00 -0.6 0.10 0.20 0.30 0.40 0.50 0.60 -0.8 0.70 Displacement (cm) Displacement (cm) Percent Difference Monotonic Pushover Curves 150% L12_H1_F2 0.8 L12 H1 F2 - L12 H1 F2 - C1 - B1 0.6 L12 H1 F2 - L12 H2 F2 - C1 - B1 L12 H1 F2 - L12 H3 F2 - C1 - B1 0.4 L12 H1 F2 - L12 H4 F2 - C1 - B1 0.2 50% 0% 0.00 L12 H1 F2 - L12 H1 F2 - C2 - B1 0.10 0.20 0.30 0.40 0.50 0.60 0.70 L12 H1 F2 - L12 H2 F2 - C2 - B1 Acceleration (g) Percent Difference in Acceleration 100% 0.0 0.00 0.10 0.20 0.30 0.40 0.50 0.60 0.70 0.80 0.90 -0.2 -50% L12 H1 F2 - L12 H3 F2 - C2 - B1 -0.4 L12 H1 F2 - L12 H4 F2 - C2 - B1 -100% -0.6 -150% -0.8 Displacement (cm) Displacement (cm) Percent Difference Monotonic Pushover Curves 150% L12_H1_F2 1.0 L12 H1 F2 - L24 H1 F2 - C1 - B1 0.8 100% L12 H1 F2 - L24 H2 F2 - C1 - B1 0.4 L12 H1 F2 - L24 H4 F2 - C1 - B1 0% 0.00 0.10 0.20 0.30 0.40 -50% 0.50 0.60 0.70 L12 H1 F2 - L24 H1 F2 - C2 - B1 L12 H1 F2 - L24 H2 F2 - C2 - B1 Acceleration (g) Percent Difference in Acceleration 0.6 L12 H1 F2 - L24 H3 F2 - C1 - B1 50% 0.2 0.0 0.00 L12 H1 F2 - L24 H3 F2 - C2 - B1 -0.2 L12 H1 F2 - L24 H4 F2 - C2 - B1 -0.4 0.20 0.40 0.60 0.80 1.00 1.20 -100% -150% -0.6 -200% -0.8 Displacement (cm) Displacement (cm) Figure 4.16. One storey, flexible wall and concrete floors building 4.2.3 Two Stories, Flexible Wall and Wood Floors Building The following are the coupling results for one storey, flexible wall and wood floor (L12_H2_F1) building. The results from coupling are mostly good for this building. One clear exception jumps off the graphs. When the flexible walled, 2 storey building is coupled with a rigid walled 1 storey building, the failure mechanism for the 2 storey building actually changes. This change actually reduces the strength and displacement capacity of the building. Figure 4.4 below demonstrates clearly illustrates this change. 22 Chapter 4. Coupled System Figure 4.17. Two stories, flexible wall and wood floors building Percent Difference Monotonic Pushover Curves 150% L12_H2_F1 0.5 L12 H1 F1 - L12 H2 F1 - C1 - B2 0.4 L12 H2 F1 - L12 H2 F1 - C1 - B1 100% 0.2 50% L12 H2 F1 - L12 H4 F1 - C1 - B1 0% 0.00 L12 H2 F1 - L24 H1 F1 - C1 - B1 0.10 0.20 0.30 0.40 0.50 0.60 L12 H2 F1 - L24 H2 F1 - C1 - B1 -50% Acceleration (g) Percent Difference in Acceleration 0.3 L12 H2 F1 - L12 H3 F1 - C1 - B1 L12 H2 F1 - L24 H3 F1 - C1 - B1 0.1 0.0 0.00 ……………………… 0.20 0.40 0.60 0.80 1.00 1.20 1.40 -0.1 -0.2 L12 H2 F1 - L24 H4 F1 - C1 - B1 -0.3 -100% -0.4 -150% -0.5 Displacement (cm) Displacement (cm) Percent Difference Monotonic Pushover Curves 80% L12_H2_F1 0.6 L12 H1 F1 - L12 H2 F1 - C2 - B2 40% L12 H2 F1 - L12 H2 F1 - C2 - B1 20% L12 H2 F1 - L12 H3 F1 - C2 - B1 0% 0.00 0.4 0.2 L12 H2 F1 - L12 H4 F1 - C2 - B1 0.20 0.40 0.60 0.80 1.00 1.20 -20% L12 H2 F1 - L24 H1 F1 - C2 - B1 -40% L12 H2 F1 - L24 H2 F1 - C2 - B1 Acceleration (g) Percent Difference in Acceleration 60% 0.0 0.00 ……………………… 0.50 1.00 1.50 2.00 2.50 3.00 3.50 4.00 4.50 5.00 3.50 4.00 4.50 5.00 -60% -0.2 L12 H2 F1 - L24 H3 F1 - C2 - B1 -80% L12 H2 F1 - L24 H4 F1 - C2 - B1 -100% -0.4 -120% -0.6 -140% Displacement (cm) Displacement (cm) Percent Difference Monotonic Pushover Curves 150% L12_H2_F1 0.5 L12 H1 F1 - L12 H2 F1 - C1 - B2 0.4 100% L12 H2 F1 - L12 H2 F1 - C1 - B1 0.2 L12 H2 F1 - L12 H4 F1 - C1 - B1 0% 0.00 0.10 0.20 0.30 0.40 -50% 0.50 0.60 0.70 L12 H1 F1 - L12 H2 F1 - C2 - B2 L12 H2 F1 - L12 H2 F1 - C2 - B1 L12 H2 F1 - L12 H3 F1 - C2 - B1 -100% L12 H2 F1 - L12 H4 F1 - C2 - B1 Acceleration (g) Percent Difference in Acceleration 0.3 L12 H2 F1 - L12 H3 F1 - C1 - B1 50% 0.1 0.0 0.00 0.50 1.00 1.50 2.00 2.50 3.00 -0.1 -0.2 -0.3 -150% -0.4 -200% -0.5 Displacement (cm) Displacement (cm) 23 Chapter 4. Coupled System Percent Difference Monotonic Pushover Curves 150% L12_H2_F1 0.6 L12 H2 F1 - L24 H1 F1 - C1 - B1 L12 H2 F1 - L24 H2 F1 - C1 - B1 0.4 L12 H2 F1 - L24 H3 F1 - C1 - B1 50% 0.2 L12 H2 F1 - L24 H4 F1 - C1 - B1 L12 H2 F1 - L24 H1 F1 - C2 - B1 0% 0.00 0.20 0.40 0.60 0.80 1.00 1.20 L12 H2 F1 - L24 H2 F1 - C2 - B1 -50% Acceleration (g) Percent Difference in Acceleration 100% 0.0 0.00 1.00 2.00 3.00 4.00 5.00 -0.2 L12 H2 F1 - L24 H3 F1 - C2 - B1 L12 H2 F1 - L24 H4 F1 - C2 - B1 -100% -0.4 -150% -0.6 Displacement (cm) Displacement (cm) Figure 4.18. Two stories, flexible wall and wood floors building 4.2.4 Two Stories, Flexible Wall and Concrete Floors Building The following are the coupling results for one storey, flexible wall and wood floor (L12_H2_F2) building. The results for this building are similar to the ones for the previous 2 storey building. In this instance, the largest change in the building’s characteristics comes from being coupled with a shorter and more rigid building both for pounding connection and the full connection. The pounding connection appears to reduce the building’s capacity in other cases as well, but not to the same magnitude. Percent Difference Monotonic Pushover Curves 100% L12_H2_F2 0.4 L12 H1 F2 - L12 H2 F2 - C1 - B2 0.3 L12 H2 F2 - L12 H2 F2 - C1 - B1 50% 0.1 L12 H2 F2 - L12 H4 F2 - C1 - B1 0% 0.00 0.20 0.40 0.60 0.80 1.00 1.20 L12 H2 F2 - L24 H1 F2 - C1 - B1 L12 H2 F2 - L24 H2 F2 - C1 - B1 -50% -100% Acceleration (g) Percent Difference in Acceleration 0.2 L12 H2 F2 - L12 H3 F2 - C1 - B1 0.0 0.00 0.20 0.40 0.60 ……………………… 0.80 1.00 1.20 1.40 1.60 -0.1 L12 H2 F2 - L24 H3 F2 - C1 - B1 -0.2 L12 H2 F2 - L24 H4 F2 - C1 - B1 -0.3 -0.4 -150% -0.5 Displacement (cm) Displacement (cm) Percent Difference Monotonic Pushover Curves 60% L12_H2_F2 0.6 L12 H1 F2 - L12 H2 F2 - C2 - B2 40% L12 H2 F2 - L12 H2 F2 - C2 - B1 0.4 L12 H2 F2 - L12 H3 F2 - C2 - B1 0% 0.00 0.2 0.10 0.20 0.30 0.40 0.50 0.60 0.70 0.80 0.90 L12 H2 F2 - L12 H4 F2 - C2 - B1 -20% L12 H2 F2 - L24 H1 F2 - C2 - B1 -40% L12 H2 F2 - L24 H2 F2 - C2 - B1 -60% L12 H2 F2 - L24 H3 F2 - C2 - B1 -80% L12 H2 F2 - L24 H4 F2 - C2 - B1 Acceleration (g) Percent Difference in Acceleration 20% 0.0 0.00 ……………………… 0.20 0.40 0.60 0.80 1.00 1.20 1.40 -0.2 -0.4 -100% -0.6 -120% Displacement (cm) Displacement (cm) 24 Chapter 4. Coupled System Percent Difference Monotonic Pushover Curves 150% L12_H2_F2 0.5 L12 H1 F2 - L12 H2 F2 - C1 - B2 0.4 L12 H2 F2 - L12 H2 F2 - C1 - B1 100% 0.2 50% L12 H2 F2 - L12 H4 F2 - C1 - B1 0% 0.00 L12 H1 F2 - L12 H2 F2 - C2 - B2 0.10 0.20 0.30 0.40 0.50 0.60 0.70 L12 H2 F2 - L12 H2 F2 - C2 - B1 -50% Acceleration (g) Percent Difference in Acceleration 0.3 L12 H2 F2 - L12 H3 F2 - C1 - B1 L12 H2 F2 - L12 H3 F2 - C2 - B1 0.1 0.0 0.00 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 -0.1 -0.2 L12 H2 F2 - L12 H4 F2 - C2 - B1 -0.3 -100% -0.4 -150% -0.5 Displacement (cm) Displacement (cm) Percent Difference Monotonic Pushover Curves 80% L12_H2_F2 0.6 L12 H2 F2 - L24 H1 F2 - C1 - B1 40% L12 H2 F2 - L24 H2 F2 - C1 - B1 20% L12 H2 F2 - L24 H3 F2 - C1 - B1 0% 0.00 0.4 0.2 L12 H2 F2 - L24 H4 F2 - C1 - B1 0.20 0.40 0.60 0.80 1.00 1.20 -20% L12 H2 F2 - L24 H1 F2 - C2 - B1 -40% L12 H2 F2 - L24 H2 F2 - C2 - B1 Acceleration (g) Percent Difference in Acceleration 60% 0.0 0.00 0.20 0.40 0.60 0.80 1.00 1.20 1.40 -60% L12 H2 F2 - L24 H3 F2 - C2 - B1 -0.2 -80% L12 H2 F2 - L24 H4 F2 - C2 - B1 -100% -0.4 -120% -140% -0.6 Displacement (cm) Displacement (cm) Figure 4.19. Two stories, flexible wall and concrete floors building 4.2.5 Three Stories, Flexible Wall and Wood Floors Building The following are the coupling results for one storey, flexible wall and wood floor (L12_H3_F1) building. Neither type of connection appears to make a consistent change to the building’s response. Wall type and height does seem to make a difference. Like those before it, the 3 storey building is most adversely affected by shorter and more rigid buildings, as seen in the final set of graphs. This is consistent with earlier data in that the change in failure mechanism for the building reduces the capacity for the building. Percent Difference Monotonic Pushover Curves 100% L12_H3_F1 0.4 L12 H1 F1 - L12 H3 F1 - C1 - B2 0.3 L12 H2 F1 - L12 H3 F1 - C1 - B2 50% 0.1 L12 H3 F1 - L12 H4 F1 - C1 - B1 0% 0.00 1.00 2.00 3.00 4.00 5.00 6.00 L12 H3 F1 - L24 H1 F1 - C1 - B1 L12 H3 F1 - L24 H2 F1 - C1 - B1 -50% -100% Acceleration (g) Percent Difference in Acceleration 0.2 L12 H3 F1 - L12 H3 F1 - C1 - B1 0.0 0.00 1.00 2.00 ……………………… 3.00 4.00 5.00 6.00 7.00 -0.1 L12 H3 F1 - L24 H3 F1 - C1 - B1 -0.2 L12 H3 F1 - L24 H4 F1 - C1 - B1 -0.3 -0.4 -150% -0.5 Displacement (cm) Displacement (cm) 25 Chapter 4. Coupled System Percent Difference Monotonic Pushover Curves 100% L12_H3_F1 0.4 L12 H1 F1 - L12 H3 F1 - C2 - B2 0.3 L12 H2 F1 - L12 H3 F1 - C2 - B2 0% 0.00 0.20 0.40 0.60 0.80 1.00 1.20 1.40 L12 H3 F1 - L12 H3 F1 - C2 - B1 0.2 L12 H3 F1 - L12 H4 F1 - C2 - B1 0.1 L12 H3 F1 - L24 H1 F1 - C2 - B1 -50% L12 H3 F1 - L24 H2 F1 - C2 - B1 Acceleration (g) Percent Difference in Acceleration 50% 0.0 0.00 ……………………… 0.50 1.00 1.50 2.00 2.50 3.00 3.50 4.00 4.50 5.00 -0.1 -100% L12 H3 F1 - L24 H3 F1 - C2 - B1 -0.2 L12 H3 F1 - L24 H4 F1 - C2 - B1 -150% -0.3 -0.4 -200% Displacement (cm) Displacement (cm) Percent Difference Monotonic Pushover Curves 80% L12_H3_F1 0.4 L12 H1 F1 - L12 H3 F1 - C1 - B2 60% 0.3 L12 H2 F1 - L12 H3 F1 - C1 - B2 L12 H3 F1 - L12 H3 F1 - C1 - B1 0.2 L12 H3 F1 - L12 H4 F1 - C1 - B1 0.1 20% 0% 0.00 0.50 1.00 1.50 2.00 2.50 3.00 L12 H1 F1 - L12 H3 F1 - C2 - B2 -20% L12 H2 F1 - L12 H3 F1 - C2 - B2 -40% Acceleration (g) Percent Difference in Acceleration 40% 0.0 0.00 1.00 2.00 3.00 4.00 5.00 6.00 4.00 5.00 6.00 -0.1 L12 H3 F1 - L12 H3 F1 - C2 - B1 -60% -0.2 L12 H3 F1 - L12 H4 F1 - C2 - B1 -80% -0.3 -100% -120% -0.4 Displacement (cm) Displacement (cm) Percent Difference Monotonic Pushover Curves 200% L12_H3_F1 0.4 L12 H3 F1 - L24 H1 F1 - C1 - B1 0.3 150% L12 H3 F1 - L24 H2 F1 - C1 - B1 0.2 L12 H3 F1 - L24 H3 F1 - C1 - B1 0.1 L12 H3 F1 - L24 H4 F1 - C1 - B1 50% 0% 0.00 L12 H3 F1 - L24 H1 F1 - C2 - B1 0.20 0.40 0.60 0.80 1.00 1.20 L12 H3 F1 - L24 H2 F1 - C2 - B1 Acceleration (g) Percent Difference in Acceleration 100% 0.0 0.00 1.00 2.00 3.00 -0.1 -50% L12 H3 F1 - L24 H3 F1 - C2 - B1 -0.2 L12 H3 F1 - L24 H4 F1 - C2 - B1 -0.3 -100% -150% -0.4 -200% -0.5 Displacement (cm) Displacement (cm) Figure 4.20. Three stories, flexible wall and wood floors building 4.2.6 Three Stories, Flexible Wall and Concrete Floors Building The following are the coupling results for one storey, flexible wall and wood floor (L12_H3_F2) building. The pounding connection appears to consistently adversely affect the response of this building. Similar to above, shorter and more rigid buildings cause the most change. The heavier floor system of concrete seems to make it more susceptible to development of soft-stories at upper levels than with the wood floors. Where rigid walls were needed to develop a soft-storey up above, now only the change in building elevation is required. From these results, it appears that heavier and taller buildings are at a greater risk to changes in their response when coupled with a shorter building next to it. 26 Chapter 4. Coupled System Percent Difference Monotonic Pushover Curves 100% L12_H3_F2 0.3 L12 H1 F2 - L12 H3 F2 - C1 - B2 L12 H2 F2 - L12 H3 F2 - C1 - B2 0.2 L12 H3 F2 - L12 H3 F2 - C1 - B1 0% 0.00 0.1 0.20 0.40 0.60 0.80 1.00 1.20 1.40 L12 H3 F2 - L12 H4 F2 - C1 - B1 L12 H3 F2 - L24 H1 F2 - C1 - B1 -50% L12 H3 F2 - L24 H2 F2 - C1 - B1 -100% Acceleration (g) Percent Difference in Acceleration 50% 0.0 0.00 ……………………… 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 -0.1 L12 H3 F2 - L24 H3 F2 - C1 - B1 L12 H3 F2 - L24 H4 F2 - C1 - B1 -150% -0.2 -200% -0.3 Displacement (cm) Displacement (cm) Percent Difference Monotonic Pushover Curves 50% L12_H3_F2 0.4 L12 H1 F2 - L12 H3 F2 - C2 - B2 0.3 L12 H2 F2 - L12 H3 F2 - C2 - B2 0.20 0.40 0.60 0.80 1.00 1.20 1.40 L12 H3 F2 - L12 H3 F2 - C2 - B1 0.2 L12 H3 F2 - L12 H4 F2 - C2 - B1 0.1 -50% L12 H3 F2 - L24 H1 F2 - C2 - B1 L12 H3 F2 - L24 H2 F2 - C2 - B1 -100% Acceleration (g) Percent Difference in Acceleration 0% 0.00 0.0 0.00 ……………………… 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00 -0.1 L12 H3 F2 - L24 H3 F2 - C2 - B1 -0.2 L12 H3 F2 - L24 H4 F2 - C2 - B1 -150% -0.3 -0.4 -200% Displacement (cm) Displacement (cm) Percent Difference Monotonic Pushover Curves 100% L12_H3_F2 0.4 L12 H1 F2 - L12 H3 F2 - C1 - B2 80% L12 H2 F2 - L12 H3 F2 - C1 - B2 40% L12 H3 F2 - L12 H3 F2 - C1 - B1 0.2 L12 H3 F2 - L12 H4 F2 - C1 - B1 0.1 20% 0% 0.00 0.50 1.00 1.50 2.00 L12 H1 F2 - L12 H3 F2 - C2 - B2 -20% L12 H2 F2 - L12 H3 F2 - C2 - B2 Acceleration (g) Percent Difference in Acceleration 0.3 60% 0.0 0.00 1.00 2.00 3.00 4.00 5.00 6.00 2.00 2.50 3.00 -0.1 -40% L12 H3 F2 - L12 H3 F2 - C2 - B1 -60% -0.2 L12 H3 F2 - L12 H4 F2 - C2 - B1 -80% -0.3 -100% -120% -0.4 Displacement (cm) Displacement (cm) Percent Difference Monotonic Pushover Curves 150% L12_H3_F2 0.4 L12 H3 F2 - L24 H1 F2 - C1 - B1 0.3 L12 H3 F2 - L24 H2 F2 - C1 - B1 50% 0% 0.00 0.20 0.40 0.60 -50% 0.80 1.00 1.20 L12 H3 F2 - L24 H3 F2 - C1 - B1 0.2 L12 H3 F2 - L24 H4 F2 - C1 - B1 0.1 L12 H3 F2 - L24 H1 F2 - C2 - B1 L12 H3 F2 - L24 H2 F2 - C2 - B1 Acceleration (g) Percent Difference in Acceleration 100% 0.0 0.00 0.50 1.00 1.50 -0.1 L12 H3 F2 - L24 H3 F2 - C2 - B1 -100% -0.2 L12 H3 F2 - L24 H4 F2 - C2 - B1 -150% -0.3 -200% -0.4 Displacement (cm) Displacement (cm) 27 Chapter 4. Coupled System Figure 4.21. Three stories, flexible wall and concrete floors building 4.2.7 Four Stories, Flexible Wall and Wood Floors Building The following are the coupling results for one storey, flexible wall and wood floor (L12_H4_F1) building. Similar to the 3 storey building before it, the 4 storey building is most affected by the height of the building next to it. If the adjacent building is shorter, then the 4 storey building develops a soft storey directly above it which reduces the building’s capacity. For buildings of a similar height and attached via a full connection, the capacity of the 4 storey building increases. L12_H4_F1 Percent Difference Monotonic Pushover Curves L12 H1 F1 - L12 H4 F1 - C1 - B2 100% 0.3 L12 H2 F1 - L12 H4 F1 - C1 - B2 0.2 L12 H3 F1 - L12 H4 F1 - C1 - B2 L12 H4 F1 - L24 H4 F1 - C1 - B2 0% 0.00 0.1 1.00 2.00 3.00 4.00 5.00 6.00 L12 H4 F1 - L24 H1 F1 - C1 - B1 -50% L12 H4 F1 - L24 H2 F1 - C1 - B1 Acceleration (g) Percent Difference in Acceleration 50% L12 H4 F1 - L24 H3 F1 - C1 - B1 -100% 0.0 0.00 1.00 2.00 3.00 4.00 5.00 6.00 7.00 8.00 -0.1 L12 H4 F1 - L24 H4 F1 - C1 - B1 -150% -0.2 -0.3 -200% Displacement (cm) Displacement (cm) Percent Difference Monotonic Pushover Curves 100% L12_H4_F1 0.3 L12 H1 F1 - L12 H4 F1 - C2 - B2 L12 H2 F1 - L12 H4 F1 - C2 - B2 0.2 L12 H3 F1 - L12 H4 F1 - C2 - B2 0% 0.00 0.1 1.00 2.00 3.00 4.00 5.00 L12 H4 F1 - L12 H4 F1 - C2 - B1 L12 H4 F1 - L24 H1 F1 - C2 - B1 -50% L12 H4 F1 - L24 H2 F1 - C2 - B1 -100% Acceleration (g) Percent Difference in Acceleration 50% 0.0 0.00 ……………………… 0.50 1.00 1.50 2.00 2.50 3.00 3.50 4.00 4.50 5.00 -0.1 L12 H4 F1 - L24 H3 F1 - C2 - B1 L12 H4 F1 - L24 H4 F1 - C2 - B1 -0.2 -150% -0.3 -200% Displacement (cm) Displacement (cm) Percent Difference Monotonic Pushover Curves 150% L12_H4_F1 0.3 L12 H1 F1 - L12 H4 F1 - C1 - B2 L12 H2 F1 - L12 H4 F1 - C1 - B2 0.2 L12 H3 F1 - L12 H4 F1 - C1 - B2 50% 0.1 L12 H4 F1 - L12 H4 F1 - C1 - B1 0% 0.00 L12 H1 F1 - L12 H4 F1 - C2 - B2 0.50 1.00 1.50 2.00 2.50 L12 H2 F1 - L12 H4 F1 - C2 - B2 -50% L12 H3 F1 - L12 H4 F1 - C2 - B2 Acceleration (g) Percent Difference in Acceleration 100% 0.0 0.00 1.00 2.00 3.00 4.00 5.00 6.00 -0.1 L12 H4 F1 - L12 H4 F1 - C2 - B1 -100% -0.2 -150% -0.3 Displacement (cm) Displacement (cm) 28 Chapter 4. Coupled System L12_H4_F1 Percent Difference Monotonic Pushover Curves L12 H4 F1 - L24 H1 F1 - C1 - B1 100% 0.3 L12 H4 F1 - L24 H2 F1 - C1 - B1 0.2 L12 H4 F1 - L24 H3 F1 - C1 - B1 L12 H4 F1 - L24 H4 F1 - C1 - B1 0% 0.00 0.1 1.00 2.00 3.00 4.00 5.00 6.00 L12 H4 F1 - L24 H1 F1 - C2 - B1 -50% L12 H4 F1 - L24 H2 F1 - C2 - B1 Acceleration (g) Percent Difference in Acceleration 50% L12 H4 F1 - L24 H3 F1 - C2 - B1 -100% 0.0 0.00 1.00 2.00 3.00 4.00 5.00 6.00 -0.1 L12 H4 F1 - L24 H4 F1 - C2 - B1 -150% -0.2 -0.3 -200% Displacement (cm) Displacement (cm) Figure 4.22. Four stories, flexible wall and wood floors building 4.2.8 Four Stories, Flexible Wall and Concrete Floors Building The following are the coupling results for one storey, flexible wall and concrete floor (L12_H4_F2) building. Again the same conclusions are drawn from these results as from the previous ones. L12_H4_F2 Percent Difference Monotonic Pushover Curves L12 H1 F2 - L12 H4 F2 - C1 - B2 50% 0.3 L12 H2 F2 - L12 H4 F2 - C1 - B2 0.2 L12 H3 F2 - L12 H4 F2 - C1 - B2 0.50 1.00 1.50 2.00 0.2 2.50 -50% L12 H4 F2 - L12 H4 F2 - C1 - B2 0.1 L12 H4 F2 - L24 H1 F2 - C1 - B1 0.1 L12 H4 F2 - L24 H2 F2 - C1 - B1 -100% Acceleration (g) Percent Difference in Acceleration 0% 0.00 0.0 0.00 0.50 1.00 1.50 2.00 2.50 -0.1 L12 H4 F2 - L24 H3 F2 - C1 - B1 -0.1 L12 H4 F2 - L24 H4 F2 - C1 - B1 -150% -0.2 -0.2 -0.3 -200% Displacement (cm) Displacement (cm) Percent Difference Monotonic Pushover Curves 100% L12_H4_F2 0.3 L12 H1 F2 - L12 H4 F2 - C2 - B2 L12 H2 F2 - L12 H4 F2 - C2 - B2 0.2 L12 H3 F2 - L12 H4 F2 - C2 - B2 0.1 L12 H4 F2 - L12 H4 F2 - C2 - B1 0% 0.00 0.20 0.40 0.60 0.80 1.00 1.20 1.40 L12 H4 F2 - L24 H1 F2 - C2 - B1 L12 H4 F2 - L24 H2 F2 - C2 - B1 -50% L12 H4 F2 - L24 H3 F2 - C2 - B1 Acceleration (g) Percent Difference in Acceleration 50% 0.0 0.00 ……………………… 0.50 1.00 1.50 2.00 -0.1 L12 H4 F2 - L24 H4 F2 - C2 - B1 -100% -0.2 -0.3 -150% Displacement (cm) Displacement (cm) 29 Chapter 4. Coupled System Percent Difference Monotonic Pushover Curves 100% L12_H4_F2 0.3 L12 H1 F2 - L12 H4 F2 - C1 - B2 80% 0.2 60% L12 H2 F2 - L12 H4 F2 - C1 - B2 40% L12 H3 F2 - L12 H4 F2 - C1 - B2 20% L12 H4 F2 - L12 H4 F2 - C1 - B1 0.1 0% 0.00 0.50 1.00 1.50 2.00 L12 H1 F2 - L12 H4 F2 - C2 - B2 -20% L12 H2 F2 - L12 H4 F2 - C2 - B2 Acceleration (g) Percent Difference in Acceleration 0.2 0.1 0.0 0.00 1.00 2.00 3.00 4.00 5.00 6.00 -0.1 -40% L12 H3 F2 - L12 H4 F2 - C2 - B2 -0.1 -60% L12 H4 F2 - L12 H4 F2 - C2 - B1 -0.2 -80% -0.2 -100% -120% -0.3 Displacement (cm) Displacement (cm) L12_H4_F2 Percent Difference Monotonic Pushover Curves L12 H4 F2 - L24 H1 F2 - C1 - B1 50% 0.3 L12 H4 F2 - L24 H2 F2 - C1 - B1 0.2 L12 H4 F2 - L24 H3 F2 - C1 - B1 0.50 1.00 1.50 2.00 2.50 L12 H4 F2 - L24 H4 F2 - C1 - B1 0.1 -50% L12 H4 F2 - L24 H1 F2 - C2 - B1 L12 H4 F2 - L24 H2 F2 - C2 - B1 -100% L12 H4 F2 - L24 H3 F2 - C2 - B1 Acceleration (g) Percent Difference in Acceleration 0% 0.00 0.0 0.00 0.50 1.00 1.50 2.00 2.50 -0.1 L12 H4 F2 - L24 H4 F2 - C2 - B1 -150% -0.2 -0.3 -200% Displacement (cm) Displacement (cm) Figure 4.23. Four stories, flexible wall and concrete floors building 4.2.9 One Storey, Rigid Wall and Wood Floors Building The following are the coupling results for one storey, flexible wall and wood floor (L24_H1_F1) building. Where the 1 storey building can reached failure under the pounding connection, the capacity of thee building is less than the single building capacity. Most of the time, however, the building could not reach capacity. There is one data set that greatly stands out from the rest and that is the interaction with the 1 storey building of flexible walls in a full connection. According to the data, when the coupled system acts in the direction of the flexible walled building, the capacity of the rigid wall building drops. This makes sense because the adjacent building has just a slightly lower capacity than this one and is at the same storey height, therefore the collapse mechanism of the weaker building cannot change. The load transferred to the rigid building weakens it as expected. 30 Chapter 4. Coupled System Percent Difference Monotonic Pushover Curves 150% L24_H1_F1 1.5 L24 H1 F1 - L24 H1 F1 - C1 - B1 100% L24 H1 F1 - L24 H2 F1 - C1 - B1 1.0 L24 H1 F1 - L24 H3 F1 - C1 - B1 0.5 0% 0.00 L24 H1 F1 - L24 H4 F1 - C1 - B1 0.05 0.10 0.15 0.20 0.25 0.30 0.35 0.40 L12 H1 F1 - L24 H1 F1 - C1 - B2 -50% L12 H2 F1 - L24 H1 F1 - C1 - B2 Acceleration (g) Percent Difference in Acceleration 50% 0.0 0.00 ……………………… 0.20 0.40 0.60 0.80 1.00 1.20 1.40 -100% -0.5 L12 H3 F1 - L24 H1 F1 - C1 - B2 -150% L12 H4 F1 - L24 H1 F1 - C1 - B2 -1.0 -200% -250% -1.5 Displacement (cm) Displacement (cm) Percent Difference Monotonic Pushover Curves 40% L24_H1_F1 1.5 L24 H1 F1 - L24 H1 F1 - C2 - B1 20% L24 H1 F1 - L24 H2 F1 - C2 - B1 0.05 0.10 0.15 0.20 0.25 0.30 0.35 0.40 1.0 0.45 L24 H1 F1 - L24 H3 F1 - C2 - B1 -20% 0.5 L24 H1 F1 - L24 H4 F1 - C2 - B1 -40% L12 H1 F1 - L24 H1 F1 - C2 - B2 -60% L12 H2 F1 - L24 H1 F1 - C2 - B2 -80% Acceleration (g) Percent Difference in Acceleration 0% 0.00 ……………………… 0.05 0.10 0.15 0.20 0.25 0.30 0.35 0.40 0.45 0.50 0.35 0.40 0.45 0.50 0.35 0.40 0.45 0.50 -0.5 L12 H3 F1 - L24 H1 F1 - C2 - B2 -100% 0.0 0.00 L12 H4 F1 - L24 H1 F1 - C2 - B2 -120% -1.0 -140% -1.5 -160% Displacement (cm) Displacement (cm) Percent Difference Monotonic Pushover Curves 60% L24_H1_F1 1.5 L24 H1 F1 - L24 H1 F1 - C1 - B1 40% L24 H1 F1 - L24 H2 F1 - C1 - B1 0% 0.00 1.0 L24 H1 F1 - L24 H3 F1 - C1 - B1 0.05 0.10 0.15 0.20 0.25 0.30 0.35 0.40 0.45 0.5 -20% L24 H1 F1 - L24 H4 F1 - C1 - B1 -40% L24 H1 F1 - L24 H1 F1 - C2 - B1 -60% L24 H1 F1 - L24 H2 F1 - C2 - B1 Acceleration (g) Percent Difference in Acceleration 20% 0.0 0.00 ……………………… 0.05 0.10 0.15 0.20 0.25 0.30 -80% -0.5 L24 H1 F1 - L24 H3 F1 - C2 - B1 -100% L24 H1 F1 - L24 H4 F1 - C2 - B1 -120% -1.0 -140% -160% -1.5 Displacement (cm) Displacement (cm) Percent Difference Monotonic Pushover Curves 150% L24_H1_F1 1.5 L12 H1 F1 - L24 H1 F1 - C1 - B2 L12 H2 F1 - L24 H1 F1 - C1 - B2 1.0 L12 H3 F1 - L24 H1 F1 - C1 - B2 50% 0.5 L12 H4 F1 - L24 H1 F1 - C1 - B2 0% 0.00 0.05 0.10 0.15 0.20 -50% 0.25 0.30 L12 H1 F1 - L24 H1 F1 - C2 - B2 L12 H2 F1 - L24 H1 F1 - C2 - B2 L12 H3 F1 - L24 H1 F1 - C2 - B2 Acceleration (g) Percent Difference in Acceleration 100% 0.0 0.00 0.05 0.10 0.15 0.20 0.25 0.30 -0.5 -100% L12 H4 F1 - L24 H1 F1 - C2 - B2 -1.0 -150% -200% -1.5 Displacement (cm) Displacement (cm) Figure 4.24. One storey, rigid wall and wood floors building 31 Chapter 4. Coupled System 4.2.10 One Storey, Rigid Wall and Concrete Floors Building The following are the coupling results for one storey, flexible wall and wood floor (L24_H1_F2) building. The same observations can be made from this 1 storey, rigid wall building as with the one above. One interesting note is that only 1 data set matches the capacity of the individual building, whereas with the wood floors, there are more buildings that match and exceed the capacity of the single building Percent Difference Monotonic Pushover Curves 150% L24_H1_F2 1.5 L24 H1 F2 - L24 H1 F2 - C1 - B1 L24 H1 F2 - L24 H2 F2 - C1 - B1 1.0 L24 H1 F2 - L24 H3 F2 - C1 - B1 50% 0.5 L24 H1 F2 - L24 H4 F2 - C1 - B1 0% 0.00 0.05 0.10 0.15 0.20 0.25 0.30 0.35 0.40 -50% L12 H1 F2 - L24 H1 F2 - C1 - B2 L12 H2 F2 - L24 H1 F2 - C1 - B2 Acceleration (g) Percent Difference in Acceleration 100% 0.0 0.00 ……………………… 0.10 0.20 0.30 0.40 0.50 0.60 0.70 0.80 -0.5 L12 H3 F2 - L24 H1 F2 - C1 - B2 -100% L12 H4 F2 - L24 H1 F2 - C1 - B2 -1.0 -150% -200% -1.5 Displacement (cm) Displacement (cm) Percent Difference Monotonic Pushover Curves 40% L24_H1_F2 1.5 L24 H1 F2 - L24 H1 F2 - C2 - B1 20% L24 H1 F2 - L24 H2 F2 - C2 - B1 0.05 0.10 0.15 0.20 0.25 0.30 0.35 0.40 1.0 0.45 L24 H1 F2 - L24 H3 F2 - C2 - B1 -20% 0.5 L24 H1 F2 - L24 H4 F2 - C2 - B1 -40% L12 H1 F2 - L24 H1 F2 - C2 - B2 -60% L12 H2 F2 - L24 H1 F2 - C2 - B2 -80% Acceleration (g) Percent Difference in Acceleration 0% 0.00 ……………………… 0.10 0.20 0.30 0.40 0.50 0.60 0.70 0.80 -0.5 L12 H3 F2 - L24 H1 F2 - C2 - B2 -100% 0.0 0.00 L12 H4 F2 - L24 H1 F2 - C2 - B2 -120% -1.0 -140% -1.5 -160% Displacement (cm) Displacement (cm) Percent Difference Monotonic Pushover Curves 60% L24_H1_F2 1.5 L24 H1 F2 - L24 H1 F2 - C1 - B1 40% L24 H1 F2 - L24 H2 F2 - C1 - B1 0% 0.00 1.0 L24 H1 F2 - L24 H3 F2 - C1 - B1 0.10 0.20 0.30 0.40 0.50 0.60 0.70 0.5 -20% L24 H1 F2 - L24 H4 F2 - C1 - B1 -40% L24 H1 F2 - L24 H1 F2 - C2 - B1 -60% L24 H1 F2 - L24 H2 F2 - C2 - B1 Acceleration (g) Percent Difference in Acceleration 20% 0.0 0.00 ……………………… 0.10 0.20 0.30 0.40 0.50 0.60 0.70 -80% L24 H1 F2 - L24 H3 F2 - C2 - B1 -0.5 -100% L24 H1 F2 - L24 H4 F2 - C2 - B1 -120% -1.0 -140% -160% -1.5 Displacement (cm) Displacement (cm) 32 Chapter 4. Coupled System Percent Difference Monotonic Pushover Curves 100% L24_H1_F2 1.5 L12 H1 F2 - L24 H1 F2 - C1 - B2 L12 H2 F2 - L24 H1 F2 - C1 - B2 1.0 L12 H3 F2 - L24 H1 F2 - C1 - B2 0% 0.00 0.5 0.10 0.20 0.30 0.40 0.50 0.60 L12 H4 F2 - L24 H1 F2 - C1 - B2 L12 H1 F2 - L24 H1 F2 - C2 - B2 -50% L12 H2 F2 - L24 H1 F2 - C2 - B2 -100% Acceleration (g) Percent Difference in Acceleration 50% 0.0 0.00 0.10 0.20 0.30 0.40 0.50 0.60 0.70 0.80 0.90 -0.5 L12 H3 F2 - L24 H1 F2 - C2 - B2 L12 H4 F2 - L24 H1 F2 - C2 - B2 -150% -1.0 -200% -1.5 Displacement (cm) Displacement (cm) Figure 4.25. One storey, rigid wall and concrete floors building 4.2.11 Two Stories, Rigid Wall and Wood Floors Building The following are the coupling results for one storey, flexible wall and wood floor (L24_H2_F1) building. All of the adjacent buildings connected by pounding connections cause a decrease in capacity of the 2 storey, rigid walled building. The full connection does not cause nearly as many buildings to fail. This is again due to the fact that a fully connection coupled system will tend to act as a single unit, which can lead to an increase of capacity from that of an individual building. This is usually occurs when acting with a taller and more flexible building. A stress concentration occurs at the change in elevation, similar to what would occur if the two buildings were actually one. Percent Difference Monotonic Pushover Curves 40% L24_H2_F1 0.8 L24 H1 F1 - L24 H2 F1 - C1 - B2 20% 0.6 0% 0.00 0.20 0.40 0.60 0.80 -20% 1.00 1.20 1.40 L24 H2 F1 - L24 H3 F1 - C1 - B1 0.4 L24 H2 F1 - L24 H4 F1 - C1 - B1 0.2 L12 H1 F1 - L24 H2 F1 - C1 - B2 -40% L12 H2 F1 - L24 H2 F1 - C1 - B2 -60% Acceleration (g) Percent Difference in Acceleration L24 H2 F1 - L24 H2 F1 - C1 - B1 0.0 0.00 ……………………… 0.50 1.00 1.50 2.00 2.50 -0.2 L12 H3 F1 - L24 H2 F1 - C1 - B2 -80% -0.4 L12 H4 F1 - L24 H2 F1 - C1 - B2 -100% -0.6 -120% -0.8 Displacement (cm) Displacement (cm) 33 Chapter 4. Coupled System Percent Difference Monotonic Pushover Curves 100% L24_H2_F1 1.0 L24 H1 F1 - L24 H2 F1 - C2 - B2 0.8 L24 H2 F1 - L24 H2 F1 - C2 - B1 0.6 L24 H2 F1 - L24 H3 F1 - C2 - B1 0.4 L24 H2 F1 - L24 H4 F1 - C2 - B1 0% 0.00 0.10 0.20 0.30 0.40 0.50 L12 H1 F1 - L24 H2 F1 - C2 - B2 L12 H2 F1 - L24 H2 F1 - C2 - B2 -50% Acceleration (g) Percent Difference in Acceleration 50% L12 H3 F1 - L24 H2 F1 - C2 - B2 0.0 0.00 ……………………… 0.50 1.00 1.50 2.00 2.50 3.00 -0.2 -0.4 L12 H4 F1 - L24 H2 F1 - C2 - B2 -100% 0.2 -0.6 -0.8 -1.0 -150% Displacement (cm) Displacement (cm) Percent Difference Monotonic Pushover Curves 60% L24_H2_F1 1.0 L24 H1 F1 - L24 H2 F1 - C1 - B2 40% 0.8 L24 H2 F1 - L24 H2 F1 - C1 - B1 20% L24 H2 F1 - L24 H3 F1 - C1 - B1 0.20 0.40 0.60 0.80 1.00 1.20 0.4 1.40 -20% L24 H2 F1 - L24 H4 F1 - C1 - B1 -40% L24 H1 F1 - L24 H2 F1 - C2 - B2 -60% L24 H2 F1 - L24 H2 F1 - C2 - B1 Acceleration (g) Percent Difference in Acceleration 0.6 0% 0.00 0.2 0.0 0.00 ……………………… 0.50 1.00 1.50 2.00 2.50 3.00 3.50 -0.2 -80% L24 H2 F1 - L24 H3 F1 - C2 - B1 -0.4 -100% L24 H2 F1 - L24 H4 F1 - C2 - B1 -0.6 -120% -0.8 -140% -160% -1.0 Displacement (cm) Displacement (cm) Percent Difference Monotonic Pushover Curves 100% L24_H2_F1 0.8 L12 H1 F1 - L24 H2 F1 - C1 - B2 0.6 L12 H2 F1 - L24 H2 F1 - C1 - B2 0% 0.00 0.10 0.20 0.30 0.40 0.50 0.60 0.70 L12 H3 F1 - L24 H2 F1 - C1 - B2 0.4 L12 H4 F1 - L24 H2 F1 - C1 - B2 0.2 0.80 L12 H1 F1 - L24 H2 F1 - C2 - B2 L12 H2 F1 - L24 H2 F1 - C2 - B2 -50% Acceleration (g) Percent Difference in Acceleration 50% 0.0 0.00 0.50 1.00 1.50 2.00 2.50 3.00 -0.2 L12 H3 F1 - L24 H2 F1 - C2 - B2 -0.4 L12 H4 F1 - L24 H2 F1 - C2 - B2 -100% -0.6 -150% -0.8 Displacement (cm) Displacement (cm) Figure 4.26. Two stories, rigid wall and wood floors building 4.2.12 Two Stories, Rigid Wall and Concrete Floors Building The following are the coupling results for one storey, flexible wall and wood floor (L24_H2_F2) building. Similar observations can be made from the 2 storey, rigid walled building with concrete floors as for the previous building with wood floors. The only difference is that less combinations allow the building to meet its original capacity and none cause an increase in capacity. 34 Chapter 4. Coupled System Percent Difference Monotonic Pushover Curves 150% L24_H2_F2 0.8 L24 H1 F2 - L24 H2 F2 - C1 - B2 0.6 L24 H2 F2 - L24 H2 F2 - C1 - B1 50% 0% 0.00 0.10 0.20 0.30 0.40 0.50 0.60 0.70 0.80 -50% L24 H2 F2 - L24 H3 F2 - C1 - B1 0.4 L24 H2 F2 - L24 H4 F2 - C1 - B1 0.2 L12 H1 F2 - L24 H2 F2 - C1 - B2 L12 H2 F2 - L24 H2 F2 - C1 - B2 Acceleration (g) Percent Difference in Acceleration 100% 0.0 0.00 ……………………… 0.10 0.20 0.30 0.40 0.50 0.60 0.70 0.80 0.90 -0.2 L12 H3 F2 - L24 H2 F2 - C1 - B2 -100% -0.4 L12 H4 F2 - L24 H2 F2 - C1 - B2 -150% -0.6 -200% -0.8 Displacement (cm) Displacement (cm) Percent Difference Monotonic Pushover Curves 20% L24_H2_F2 0.8 L24 H1 F2 - L24 H2 F2 - C2 - B2 0% 0.00 0.10 0.20 0.30 0.40 0.50 0.6 0.60 L24 H2 F2 - L24 H2 F2 - C2 - B1 L24 H2 F2 - L24 H3 F2 - C2 - B1 0.4 L24 H2 F2 - L24 H4 F2 - C2 - B1 0.2 -40% -60% L12 H1 F2 - L24 H2 F2 - C2 - B2 -80% L12 H2 F2 - L24 H2 F2 - C2 - B2 -100% Acceleration (g) Percent Difference in Acceleration -20% 0.0 0.00 ……………………… 0.20 0.40 0.60 0.80 1.00 1.20 -0.2 L12 H3 F2 - L24 H2 F2 - C2 - B2 -120% -0.4 L12 H4 F2 - L24 H2 F2 - C2 - B2 -140% -0.6 -160% -0.8 -180% Displacement (cm) Displacement (cm) Percent Difference Monotonic Pushover Curves 100% L24_H2_F2 0.8 L24 H1 F2 - L24 H2 F2 - C1 - B2 0.6 L24 H2 F2 - L24 H2 F2 - C1 - B1 0% 0.00 0.10 0.20 0.30 0.40 0.50 0.60 0.70 0.80 0.90 L24 H2 F2 - L24 H3 F2 - C1 - B1 0.4 L24 H2 F2 - L24 H4 F2 - C1 - B1 0.2 L24 H1 F2 - L24 H2 F2 - C2 - B2 -50% L24 H2 F2 - L24 H2 F2 - C2 - B1 Acceleration (g) Percent Difference in Acceleration 50% 0.0 0.00 ……………………… 0.20 0.40 0.60 0.80 1.00 -0.2 -100% L24 H2 F2 - L24 H3 F2 - C2 - B1 -0.4 L24 H2 F2 - L24 H4 F2 - C2 - B1 -150% -0.6 -200% -0.8 Displacement (cm) Displacement (cm) Percent Difference Monotonic Pushover Curves 50% L24_H2_F2 0.8 L12 H1 F2 - L24 H2 F2 - C1 - B2 0.6 L12 H2 F2 - L24 H2 F2 - C1 - B2 0.10 0.20 0.30 0.40 0.50 0.60 0.70 0.80 0.90 L12 H3 F2 - L24 H2 F2 - C1 - B2 0.4 L12 H4 F2 - L24 H2 F2 - C1 - B2 0.2 -50% L12 H1 F2 - L24 H2 F2 - C2 - B2 L12 H2 F2 - L24 H2 F2 - C2 - B2 -100% Acceleration (g) Percent Difference in Acceleration 0% 0.00 0.0 0.00 0.20 0.40 0.60 0.80 1.00 1.20 -0.2 L12 H3 F2 - L24 H2 F2 - C2 - B2 -0.4 L12 H4 F2 - L24 H2 F2 - C2 - B2 -150% -0.6 -200% -0.8 Displacement (cm) Displacement (cm) Figure 4.27. Two stories, rigid wall and concrete floors building 35 Chapter 4. Coupled System 4.2.13 Three Stories, Rigid Wall and Wood Floors Building The following are the coupling results for one storey, flexible wall and wood floor (L24_H3_F1) building. Similar observations can be made as previous made above. Percent Difference Monotonic Pushover Curves 150% L24_H3_F1 0.6 L24 H1 F1 - L24 H3 F1 - C1 - B2 L24 H2 F1 - L24 H3 F1 - C1 - B2 0.4 L24 H3 F1 - L24 H3 F1 - C1 - B1 50% 0.2 L24 H3 F1 - L24 H4 F1 - C1 - B1 0% 0.00 L12 H1 F1 - L24 H3 F1 - C1 - B2 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 L12 H2 F1 - L24 H3 F1 - C1 - B2 Acceleration (g) Percent Difference in Acceleration 100% -50% ……………………… 0.0 0.00 0.50 1.00 1.50 2.00 2.50 3.00 -0.2 L12 H4 F1 - L24 H3 F1 - C1 - B2 -100% -0.4 -150% -0.6 Displacement (cm) Displacement (cm) Percent Difference Monotonic Pushover Curves 40% L24_H3_F1 0.8 L24 H1 F1 - L24 H3 F1 - C2 - B2 20% 0.6 0.50 1.00 1.50 2.00 2.50 3.00 -20% L24 H3 F1 - L24 H3 F1 - C2 - B1 0.4 L24 H3 F1 - L24 H4 F1 - C2 - B1 0.2 L12 H1 F1 - L24 H3 F1 - C2 - B2 -40% L12 H2 F1 - L24 H3 F1 - C2 - B2 Acceleration (g) Percent Difference in Acceleration L24 H2 F1 - L24 H3 F1 - C2 - B2 0% 0.00 -60% 0.0 0.00 ……………………… 0.50 1.00 1.50 2.00 2.50 3.00 3.50 4.00 4.50 5.00 3.50 4.00 4.50 5.00 -0.2 L12 H3 F1 - L24 H3 F1 - C2 - B2 -0.4 -80% L12 H4 F1 - L24 H3 F1 - C2 - B2 -0.6 -100% -0.8 -120% Displacement (cm) Displacement (cm) Percent Difference Monotonic Pushover Curves 150% L24_H3_F1 0.8 L24 H1 F1 - L24 H3 F1 - C1 - B2 0.6 L24 H2 F1 - L24 H3 F1 - C1 - B2 L24 H3 F1 - L24 H3 F1 - C1 - B1 0.4 L24 H3 F1 - L24 H4 F1 - C1 - B1 0.2 50% 0% 0.00 L24 H1 F1 - L24 H3 F1 - C2 - B2 0.20 0.40 0.60 0.80 1.00 1.20 1.40 L24 H2 F1 - L24 H3 F1 - C2 - B2 Acceleration (g) Percent Difference in Acceleration 100% 0.0 0.00 ……………………… 0.50 1.00 1.50 2.00 2.50 3.00 -0.2 -50% L24 H3 F1 - L24 H3 F1 - C2 - B1 -0.4 L24 H3 F1 - L24 H4 F1 - C2 - B1 -100% -0.6 -150% -0.8 Displacement (cm) Displacement (cm) 36 Chapter 4. Coupled System Percent Difference Monotonic Pushover Curves 100% L24_H3_F1 0.6 L12 H1 F1 - L24 H3 F1 - C1 - B2 L12 H2 F1 - L24 H3 F1 - C1 - B2 0.4 L12 H3 F1 - L24 H3 F1 - C1 - B2 0.2 L12 H4 F1 - L24 H3 F1 - C1 - B2 0% 0.00 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 L12 H1 F1 - L24 H3 F1 - C2 - B2 L12 H2 F1 - L24 H3 F1 - C2 - B2 -50% Acceleration (g) Percent Difference in Acceleration 50% 0.0 0.00 0.50 1.00 1.50 2.00 2.50 3.00 3.50 4.00 -0.2 L12 H3 F1 - L24 H3 F1 - C2 - B2 L12 H4 F1 - L24 H3 F1 - C2 - B2 -100% -0.4 -150% -0.6 Displacement (cm) Displacement (cm) Figure 4.28. Three stories, rigid wall and wood floors building 4.2.14 Three Stories, Rigid Wall and Concrete Floors Building The following are the coupling results for one storey, flexible wall and wood floor (L24_H3_F2) building. The effects of coupling on this building are similar to the rigid walled ones above. One difference is that every building with the same length of wall caused a reduction in the building’s capacity, as can be seen in the third set of graphs. Percent Difference Monotonic Pushover Curves 80% L24_H3_F2 0.6 L24 H1 F2 - L24 H3 F2 - C1 - B2 60% L24 H2 F2 - L24 H3 F2 - C1 - B2 0.4 L24 H3 F2 - L24 H3 F2 - C1 - B1 20% 0.2 L24 H3 F2 - L24 H4 F2 - C1 - B1 0% 0.00 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 L12 H1 F2 - L24 H3 F2 - C1 - B2 -20% L12 H2 F2 - L24 H3 F2 - C1 - B2 -40% Acceleration (g) Percent Difference in Acceleration 40% 0.0 0.00 ……………………… 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.00 1.20 1.40 -0.2 -60% L12 H4 F2 - L24 H3 F2 - C1 - B2 -80% -0.4 -100% -120% -0.6 Displacement (cm) Displacement (cm) Percent Difference Monotonic Pushover Curves 100% L24_H3_F2 0.6 L24 H1 F2 - L24 H3 F2 - C2 - B2 L24 H2 F2 - L24 H3 F2 - C2 - B2 0.4 L24 H3 F2 - L24 H3 F2 - C2 - B1 0% 0.00 0.2 0.10 0.20 0.30 0.40 0.50 0.60 0.70 0.80 L24 H3 F2 - L24 H4 F2 - C2 - B1 L12 H1 F2 - L24 H3 F2 - C2 - B2 -50% L12 H2 F2 - L24 H3 F2 - C2 - B2 -100% L12 H3 F2 - L24 H3 F2 - C2 - B2 Acceleration (g) Percent Difference in Acceleration 50% 0.0 0.00 ……………………… 0.20 0.40 0.60 0.80 -0.2 L12 H4 F2 - L24 H3 F2 - C2 - B2 -0.4 -150% -0.6 -200% Displacement (cm) Displacement (cm) 37 Chapter 4. Coupled System Percent Difference Monotonic Pushover Curves 150% L24_H3_F2 0.6 L24 H1 F2 - L24 H3 F2 - C1 - B2 L24 H2 F2 - L24 H3 F2 - C1 - B2 0.4 L24 H3 F2 - L24 H3 F2 - C1 - B1 50% 0.2 L24 H3 F2 - L24 H4 F2 - C1 - B1 0% 0.00 L24 H1 F2 - L24 H3 F2 - C2 - B2 0.10 0.20 0.30 0.40 0.50 0.60 0.70 L24 H2 F2 - L24 H3 F2 - C2 - B2 -50% Acceleration (g) Percent Difference in Acceleration 100% 0.0 0.00 ……………………… 0.20 0.40 0.60 0.80 1.00 1.20 1.40 -0.2 L24 H3 F2 - L24 H3 F2 - C2 - B1 L24 H3 F2 - L24 H4 F2 - C2 - B1 -100% -0.4 -150% -0.6 Displacement (cm) Displacement (cm) Percent Difference Monotonic Pushover Curves 60% L24_H3_F2 0.6 L12 H1 F2 - L24 H3 F2 - C1 - B2 40% L12 H2 F2 - L24 H3 F2 - C1 - B2 0.4 L12 H3 F2 - L24 H3 F2 - C1 - B2 0% 0.00 0.2 0.20 0.40 0.60 0.80 1.00 1.20 1.40 L12 H4 F2 - L24 H3 F2 - C1 - B2 -20% L12 H1 F2 - L24 H3 F2 - C2 - B2 -40% L12 H2 F2 - L24 H3 F2 - C2 - B2 -60% L12 H3 F2 - L24 H3 F2 - C2 - B2 -80% L12 H4 F2 - L24 H3 F2 - C2 - B2 Acceleration (g) Percent Difference in Acceleration 20% 0.0 0.00 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 -0.2 -0.4 -100% -120% -0.6 Displacement (cm) Displacement (cm) Figure 4.29. Three stories, rigid wall and concrete floors building 4.2.15 Four Stories, Rigid Wall and Wood Floors Building The following are the coupling results for one storey, flexible wall and wood floor (L24_H4_F1) building. This building performs similarly to the 3 storey counterpart with wood floors. Percent Difference Monotonic Pushover Curves 150% L24_H4_F1 0.5 L24 H1 F1 - L24 H4 F1 - C1 - B2 0.4 L24 H2 F1 - L24 H4 F1 - C1 - B2 100% 0.2 L24 H4 F1 - L24 H4 F1 - C1 - B1 0% 0.00 L12 H1 F1 - L24 H4 F1 - C1 - B2 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 L12 H2 F1 - L24 H4 F1 - C1 - B2 -50% L12 H3 F1 - L24 H4 F1 - C1 - B2 L12 H4 F1 - L24 H4 F1 - C1 - B2 Acceleration (g) Percent Difference in Acceleration 0.3 L24 H3 F1 - L24 H4 F1 - C1 - B2 50% 0.1 0.0 0.00 ……………………… 0.50 1.00 1.50 2.00 2.50 3.00 3.50 -0.1 -0.2 -0.3 -100% -0.4 -150% -0.5 Displacement (cm) Displacement (cm) 38 Chapter 4. Coupled System Percent Difference Monotonic Pushover Curves 40% L24_H4_F1 0.5 L24 H1 F1 - L24 H4 F1 - C2 - B2 0.4 20% L24 H2 F1 - L24 H4 F1 - C2 - B2 0.50 1.00 1.50 2.00 2.50 3.00 3.50 4.00 L24 H3 F1 - L24 H4 F1 - C2 - B2 0.2 L24 H4 F1 - L24 H4 F1 - C2 - B1 -20% L12 H1 F1 - L24 H4 F1 - C2 - B2 -40% L12 H2 F1 - L24 H4 F1 - C2 - B2 Acceleration (g) Percent Difference in Acceleration 0.3 0% 0.00 -60% L12 H3 F1 - L24 H4 F1 - C2 - B2 0.1 ……………………… 0.0 0.00 1.00 2.00 3.00 4.00 5.00 6.00 -0.1 -0.2 -80% L12 H4 F1 - L24 H4 F1 - C2 - B2 -0.3 -100% -0.4 -0.5 -120% Displacement (cm) Displacement (cm) Percent Difference Monotonic Pushover Curves 60% L24_H4_F1 0.5 L24 H1 F1 - L24 H4 F1 - C1 - B2 0.4 40% L24 H2 F1 - L24 H4 F1 - C1 - B2 0.3 L24 H3 F1 - L24 H4 F1 - C1 - B2 0.2 0% 0.00 0.50 1.00 1.50 2.00 2.50 3.00 L24 H4 F1 - L24 H4 F1 - C1 - B1 -20% L24 H1 F1 - L24 H4 F1 - C2 - B2 -40% L24 H2 F1 - L24 H4 F1 - C2 - B2 -60% L24 H3 F1 - L24 H4 F1 - C2 - B2 -80% L24 H4 F1 - L24 H4 F1 - C2 - B1 Acceleration (g) Percent Difference in Acceleration 20% 0.1 0.0 0.00 ……………………… 0.50 1.00 1.50 2.00 2.50 3.00 3.50 4.00 3.00 3.50 4.00 -0.1 -0.2 -0.3 -100% -0.4 -120% -0.5 Displacement (cm) Displacement (cm) Percent Difference Monotonic Pushover Curves 100% L24_H4_F1 0.5 L12 H1 F1 - L24 H4 F1 - C1 - B2 80% 0.4 60% L12 H2 F1 - L24 H4 F1 - C1 - B2 40% L12 H3 F1 - L24 H4 F1 - C1 - B2 20% L12 H4 F1 - L24 H4 F1 - C1 - B2 0.2 0% 0.00 0.20 0.40 0.60 0.80 1.00 1.20 1.40 L12 H1 F1 - L24 H4 F1 - C2 - B2 -20% L12 H2 F1 - L24 H4 F1 - C2 - B2 Acceleration (g) Percent Difference in Acceleration 0.3 0.1 0.0 0.00 0.50 1.00 1.50 2.00 2.50 -0.1 -40% L12 H3 F1 - L24 H4 F1 - C2 - B2 -60% L12 H4 F1 - L24 H4 F1 - C2 - B2 -80% -0.2 -0.3 -0.4 -100% -120% -0.5 Displacement (cm) Displacement (cm) Figure 4.30. Four stories, rigid wall and wood floors building 4.2.16 Four Stories, Rigid Wall and Concrete Floors Building The following are the coupling results for one storey, flexible wall and wood floor (L24_H4_F2) building. Coupling is good for the tallest building with rigid walls. Only a few combinations cause a lowering of the building’s capacity, and all of those are within the full inter-building connection. The smaller and sometimes more rigid buildings help prop this building up and the 4 storey rigid wall building has the ability to refrain from developing a soft-storey at the change of elevation with the shorter adjacent one. It is strange that the taller building would as little of an effect from the coupling as it does, especially when the 3 storey rigid walled buildings are greatly affected by it. 39 Chapter 4. Coupled System Percent Difference Monotonic Pushover Curves 120% L24_H4_F2 0.3 L24 H1 F2 - L24 H4 F2 - C1 - B2 100% L24 H2 F2 - L24 H4 F2 - C1 - B2 0.2 L24 H3 F2 - L24 H4 F2 - C1 - B2 60% 0.1 L24 H4 F2 - L24 H4 F2 - C1 - B1 40% L12 H1 F2 - L24 H4 F2 - C1 - B2 20% 0% 0.00 L12 H2 F2 - L24 H4 F2 - C1 - B2 0.20 0.40 0.60 0.80 1.00 1.20 Acceleration (g) Percent Difference in Acceleration 80% 0.0 0.00 ……………………… 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.40 -0.1 L12 H3 F2 - L24 H4 F2 - C1 - B2 -20% L12 H4 F2 - L24 H4 F2 - C1 - B2 -40% -0.2 -60% -80% -0.3 Displacement (cm) Displacement (cm) Percent Difference Monotonic Pushover Curves 100% L24_H4_F2 0.5 L24 H1 F2 - L24 H4 F2 - C2 - B2 0.4 L24 H2 F2 - L24 H4 F2 - C2 - B2 0.3 L24 H3 F2 - L24 H4 F2 - C2 - B2 0.2 L24 H4 F2 - L24 H4 F2 - C2 - B1 0% 0.00 0.20 0.40 0.60 0.80 1.00 1.20 1.40 L12 H1 F2 - L24 H4 F2 - C2 - B2 L12 H2 F2 - L24 H4 F2 - C2 - B2 -50% Acceleration (g) Percent Difference in Acceleration 50% L12 H3 F2 - L24 H4 F2 - C2 - B2 0.0 0.00 ……………………… 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 -0.1 -0.2 L12 H4 F2 - L24 H4 F2 - C2 - B2 -100% 0.1 -0.3 -0.4 -0.5 -150% Displacement (cm) Displacement (cm) Percent Difference Monotonic Pushover Curves 150% L24_H4_F2 0.3 L24 H1 F2 - L24 H4 F2 - C1 - B2 L24 H2 F2 - L24 H4 F2 - C1 - B2 0.2 L24 H3 F2 - L24 H4 F2 - C1 - B2 50% 0.1 L24 H4 F2 - L24 H4 F2 - C1 - B1 0% 0.00 L24 H1 F2 - L24 H4 F2 - C2 - B2 0.20 0.40 0.60 0.80 1.00 1.20 L24 H2 F2 - L24 H4 F2 - C2 - B2 -50% Acceleration (g) Percent Difference in Acceleration 100% 0.0 0.00 c ……………………… 0.20 0.40 0.60 0.80 1.00 1.20 1.40 -0.1 L24 H3 F2 - L24 H4 F2 - C2 - B2 L24 H4 F2 - L24 H4 F2 - C2 - B1 -100% -0.2 -150% -0.3 Displacement (cm) Displacement (cm) Percent Difference Monotonic Pushover Curves 150% L24_H4_F2 0.5 L12 H1 F2 - L24 H4 F2 - C1 - B2 0.4 L12 H2 F2 - L24 H4 F2 - C1 - B2 100% 0.2 50% L12 H4 F2 - L24 H4 F2 - C1 - B2 0% 0.00 L12 H1 F2 - L24 H4 F2 - C2 - B2 0.20 0.40 0.60 0.80 1.00 1.20 1.40 L12 H2 F2 - L24 H4 F2 - C2 - B2 -50% L12 H3 F2 - L24 H4 F2 - C2 - B2 L12 H4 F2 - L24 H4 F2 - C2 - B2 Acceleration (g) Percent Difference in Acceleration 0.3 L12 H3 F2 - L24 H4 F2 - C1 - B2 0.1 0.0 0.00 0.20 0.40 0.60 0.80 1.00 1.20 1.40 -0.1 -0.2 -0.3 -100% -0.4 -150% -0.5 Displacement (cm) Displacement (cm) Figure 4.31. Four stories, rigid wall and concrete floors building 40 Chapter 4. Coupled System 4.3 Discussion As the adjacent building becomes taller and all other parameters remain constant, such as the wall thickness and material properties, the base shear for the adjacent building increases and it becomes weaker. As these buildings become weaker, they tend to transfer their inertial forces through the coupled connection to the stronger building next to it. This proves detrimental for the building of interest. When the building of interest is the weaker one, then the effects of the force transfer is slightly more complicated. Sometimes the building becomes stronger because now the inertial forces are distributed over a larger base. Other times it actually weakens because a soft storey develops in the upper floors as seen in Figure 4.19. In general, a flexible building acting on a more rigid building reduces the strength of the rigid building. The results are easily understood – the flexible building still failed prior to the rigid building. Weakening of the rigid building, however, is important to understand because it will factor into repair costs for earthquake damage. Pounding connections tended to exhibit this behaviour more so than their fully connected counterparts. The fully connected buildings acted more as a single structure. Because of this, the failure mode of the fully connected systems sometimes included failure of the rigid building. Other times a soft storey would develop in the flexible building leading to failure of the system through the soft storey, similar to the pounding connections. In short, coupling a more flexible building to a rigid building did not cause the rigid building to fail first, but it did change its behaviour and make it substantially weaker. 4.3.1 Pounding Connection Coupled buildings by a pounding connection demonstrate a change in behaviour only when the more flexible building acts upon the more rigid one. When the more flexible building moves in the opposite direction of the rigid building, neither building sees a change in their response curve. Figure 4.19 below provides a few examples of this behaviour. Note that in each case the rigid building is the 2 storey one and the flexible building is the 4 storey one. In most cases where the more flexible building extended one storey or more above the rigid one, a soft storey developed at the interaction of the buildings. Figure 4.19 also demonstrates this phenomenon. In this condition, both buildings experience a reduction in strength on their response curves. This suggests that pounding between buildings is almost always at least slightly detrimental. 41 Chapter 4. Coupled System Figure 4.32. Pounding connection 4.3.2 Full Connection The main different between the full connection and the pounding connection is that the full connection causes the coupled system to act as one building. Neither building is independent in either direction. Similar to the pounding connection, interaction through a full building connection between a short building and a taller building tends to lead to the development of a soft storey just above the shorter building. A major difference is that unlike the pounding connection, the full connection experiences this change in both directions. This means that when buildings share walls and are of different heights, there is a chance that a stress concentration could form where the shorter building ends. This concentration of stresses in no different than if the coupled system were one building. Figure 4.20 below shows the development of these soft stories and also the increase demands on the shorter building, which is not always present in the pounding connection system. 42 Chapter 4. Coupled System Figure 4.33. Full connection The type of system that typically causes the greatest decrease in single building capacity is a coupled system with flexible walls acting against a shorter building with more rigid walls. In almost every instance, the taller building develops a soft-storey failure mechanism just above the shorter building and fails at a lower acceleration and displacement than it would on its own. In studying vulnerability parameters on a larger scale, this condition should be noted and included and capturing the effect of building interaction. Another important note is that the pounding connection between buildings tended to change building responses more than the full connection. This means that buildings which share a load bearing masonry wall are less likely to observe damage than those that are simply spaced closely together. There are a few instances when a full connection between buildings is actually worse than a pounding one. Most notably is again when the building heights are substantially different and the shorter one has more rigid walls than the taller. 43 Chapter 4. Coupled System Percent Difference Monotonic Pushover Curves 100% L24_H3_F1 0.8 L24 H3 F1 - L24 H3 F1 - C1 - B1 0.6 L24 H3 F1 - L24 H3 F1 - C2 - B1 0% 0.00 0.20 0.40 0.60 0.80 1.00 1.20 L24 H3 F2 - L24 H3 F2 - C1 - B1 0.4 L24 H3 F2 - L24 H3 F2 - C2 - B1 0.2 Acceleration (g) Percent Difference in Acceleration 50% 1.40 -50% 0.0 0.00 1.00 2.00 3.00 4.00 5.00 6.00 4.00 5.00 6.00 -0.2 -0.4 -100% -0.6 -150% -0.8 Displacement (cm) Displacement (cm) Percent Difference Monotonic Pushover Curves 100% L24_H3_F2 0.8 L24 H3 F1 - L24 H3 F1 - C1 - B1 0.6 L24 H3 F1 - L24 H3 F1 - C2 - B1 0% 0.00 0.20 0.40 0.60 0.80 -50% 1.00 1.20 1.40 L24 H3 F2 - L24 H3 F2 - C1 - B1 0.4 L24 H3 F2 - L24 H3 F2 - C2 - B1 0.2 Acceleration (g) Percent Difference in Acceleration 50% 0.0 0.00 1.00 2.00 3.00 -0.2 -0.4 -100% -0.6 -150% -0.8 Displacement (cm) Displacement (cm) Figure 4.34. Three stories, rigid walls buildings for Row Conglomerations Of all the buildings in this study, building interaction influences the response of the 3 storey, rigid walled buildings more than any other type of system. An influence of the interaction can even be seen in the pounding condition between the same buildings. Because of these differences, the 3 storey rigid walled building with wood floors is the building of choice for the row conglomeration study described in the following chapter. 44 Chapter 5. Simple Conglomeration 5. CONGLOMERATIONS One of the remaining relations to observe is the effect on building responses with respect to its location within a longer building conglomeration. This section on building conglomeration addresses that relationship. The purpose is to indicate what positions impact the building’s response the most. 5.1 Analysis A conglomeration consists of a row of buildings oriented in much the same fashion as the coupled system. They consist of 3, 6 and 9 buildings with either pounding or full connections between each building. A building with concrete floors is included either as an external building or an internal building in each group of conglomerations to model the effects of a heavier building acting on lighter ones. A full list of conglomerations analyzed is listed in Table 5.1 below. From the coupled system analysis in the previous chapter, 3 storey buildings with rigid walls and wood floors were determined to have the most impact on adjacent building response. These buildings were thus the only ones considered in the conglomeration study. This was done in order to limit the number of models required to capture the impact of position in a row of buildings on a building’s behaviour. A list of the different conglomerations in this study is located in Appendix C. To reduce the number of models further, only data was collected for an exterior building and an interior building for each of the conglomerations. The interior building was the middle building, or in the case of the 6 building conglomeration, the fourth building from the left. A mix of different inter-building connections within a conglomeration is not considered in this study. Other parameters, such as building height and wall thickness, are also excluded from the conglomeration portion of the study. The focus of the row conglomeration is on building position. Including other parameters previously studied in the coupled systems chapter would complicate the study of this parameter to the point that obtaining useful information would become difficult. For that reason, a changing pattern of building connections is not considered necessary to understand the influence of building interaction based on a buildings position. Such a study would complicate the parameter too much to extract useful information. 45 Chapter 5. Simple Conglomeration 5.2 Monotonic Pushover Results The standard building of study for the row conglomeration is the 3 storey, rigid walled building with wood floors. The results are presented for each type of row conglomeration for this building, highlighting the effects of the conglomeration on the building’s response in each case. The 3 storey building pushover curve is used as a reference point to discuss the effects of other buildings on the curve. Percentage difference curves are created by taking the difference in acceleration over the average acceleration at various displacements along each curve as a comparison. The original pushover curves are provided next to the percentage difference curves for each case. The percentage difference curves demonstrate the effect of the conglomeration on the response of the building. Table 5.6. Notation description for navigating result files Notation L12 L24 H1 H2 H3 H4 F1 F2 C1 C2 B1 B2 B4 B5 Description Length of in-plane wall = 12 m Length of in-plane wall = 24 m Number of stories = 1 with individual storey heights matching previous table Number of stories = 2 with individual storey heights matching previous table Number of stories = 3 with individual storey heights matching previous table Number of stories = 4 with individual storey heights matching previous table Floor composition = wood Floor composition = concrete Inter-building connection type = pounding Inter-building connection type = full connection Building 1 in a coupled or row conglomeration system Building 2 in a coupled or row conglomeration system Building 4 in a row conglomeration system Building 5 in a row conglomeration system Example: L12 H1 F2 – Single building with length = 12 m, 1 storey tall, Concrete floors 3 * L24 H3 F1 – C1 – B2 w/ external F2 – This is a 3 building row conglomeration system with first building having a length of 24 m, a height of 3 stories, and concrete floors. The second building has a length of 24 m, height of 3 stories and wood floors. The third building has a length of 24 m, height of 3 stories and wood floors. The connection between the buildings is a pounding connection and the data presented is for the second building, or the interior building of the row conglomeration. 46 Chapter 5. Simple Conglomeration Figure 5.35. Example: 3 * L24 H3 F1 – C1 – B2 w/ external F2 5.2.1 Three building conglomerations The following results are for the 3 building conglomeration systems. The most noticeable trend in the data is a negative effect due to the influence of surrounding buildings within a conglomeration, with a few exceptions. These exceptions occur only when the conglomeration is fully connected between each building. With the buildings being fully connected, the conglomeration actually gains capacity. This trend is illustrated in Figure 5.2 below. L24_H3_F1 Percent Difference Monotonic Pushover Curves 3 * L24 H3 F1 - C1 - B1 40% 0.8 3 * L24 H3 F1 - C1 - B2 0.6 20% 3 * L24 H3 F1 - C2 - B1 0.50 1.00 1.50 2.00 2.50 3 * L24 H3 F1 - C2 - B2 0.2 -20% 3 * L24 H3 F1 - C1 - B2 w/ external F2 -40% 3 * L24 H3 F1 - C1 - B3 w/ external F2 Acceleration (g) Percent Difference in Acceleration 0.4 0% 0.00 0.0 0.00 0.50 1.00 1.50 2.00 2.50 -0.2 -60% 3 * L24 H3 F1 - C2 - B2 w/ external F2 -80% 3 * L24 H3 F1 - C2 - B3 w/ external F2 -0.4 3 * L24 H3 F1 - C1 - B1 w/ internal F2 -100% -0.6 -0.8 Displacement (cm) Displacement (cm) Figure 5.36. 3 building conglomerations results A - 3 Buildings - L24 H3 F1 – Pounding Connection 47 Chapter 5. Simple Conglomeration B - 3 Buildings - L24 H3 F1 – Full Connection Figure 5.37. 3 Building conglomeration models The above figure illustrates the failure mechanism of buildings with only wood floors. The plan view for both the pounding and full connection conglomerations show that the middle wall fails prior to the exterior walls. The elevation below each of the plan views is of the interior wall. The failure mechanism appears to be similar for both conglomerations. Walls on both the first and second storey fail in shear while the top storey wall does not fail. The biggest difference between the conglomerations is that the smaller walls at the end of each building do not fail in the pounding connection while they do fail in the full connection. This is partly the reason why building that are fully connected perform better than those using the pounding connection. A - 3 Buildings - L24 H3 F1 – Pounding Connection w/ external F2 on the left 48 Chapter 5. Simple Conglomeration B - 3 Buildings - L24 H3 F1 – Full Connection w/ external F2 on the left C - 3 Buildings - L24 H3 F1 – Pounding Connection w/ internal F2 in the centre D - 3 Buildings - L24 H3 F1 – Full Connection w/ internal F2 in the centre Figure 5.38. 3 building conglomeration models 49 Chapter 5. Simple Conglomeration Another interesting point is the transfer of inertial forces between buildings when a concrete floor building is included in the conglomeration. This transfer is most noticeable when observing the pounding connection systems. As seen in group A of Figure 5.4 above, the external concrete floor building is on the left and the wood floor buildings are the 2 on the right. The internal wall elevation shows that inertial forces are transferred from the concrete floor building to the wood floor building because the buildings on the right actually separate from the concrete building. This notion is confirmed by observing the external wall elevations in that the walls all move the same amount. This is because the concrete floors are stiff enough to distribute the inertial forces to the exterior walls of the concrete building which then gets transferred to the exterior walls of the wood floor buildings on the right. This concept is again illustrated in group C of Figure 5.4. Here, the internal building has concrete floors while both external buildings have wood floors. The exterior wall elevations shows the same phenomenon occurring is described above. The wood floor building on the left does not show any signs of failure in the exterior walls because the wood floors are not stiff enough to transfer the inertial forces to these walls. On the other hand, the wood floor building on the right does show signs of failure in the exterior walls because of load transferred from the concrete floor building. Again the exterior building furthest to the right separates from the concrete building at failure. This is seen in the interior wall elevation of group C. L24_H3_F1 Percent Difference Monotonic Pushover Curves L24_H3_F2 20% 0.6 10% 0.50 1.00 1.50 2.00 2.50 0.2 -10% Acceleration (g) Percent Difference in Acceleration 0.4 0% 0.00 -20% 0.0 0.00 0.50 1.00 1.50 2.00 2.50 -30% -0.2 -40% -0.4 -50% -0.6 -60% Displacement (cm) Displacement (cm) Figure 5.39. Comparison of wood vs concrete floors These observations are of particular interest when comparing them to the behaviour between the individual 3 story buildings. Above in Figure 5.5, a 3 storey building with wood floors and rigid walls is compared to a 3 storey building with concrete floors and rigid walls. As can be seen in the graphs, the two buildings observe similar levels of maximum acceleration and quite different levels of ultimate displacement. The building with concrete floors fails at a lower displacement level than the one with wood floors. The building with concrete floors also has a shallower initial ascent than the one with wood floors. This makes sense because 50 Chapter 5. Simple Conglomeration the one with concrete floors is heavier and thus will have larger forces from the same acceleration levels as the building with wood floors. In this regard, it is particularly interesting to note that in group A of Figure 5.5 above, the building with concrete floors on the left does not have as large of displacements as those with wood floor on the right. This clearly suggests that some of its inertial forces are transferred to the other buildings resulting in larger displacements at lower levels of acceleration. None of the above observations are noticeable in the full connection systems. This is because the concrete floors distribute the inertial forces to the exterior walls for the entire system. When comparing the plan view of these building conglomerations with that of the original full connection system, i.e. the one without any concrete floor diaphragms present, one notices that the failure mode is different. All three walls appear to displace the same distance at failure, whereas the interior wall of the original system clearly displaces further. The difference, however, is that the increase of inertial forces due to the increase of dead load from the concrete floors still negatively effects the other buildings as seen in Figure 5.4 above. Unlike the original conglomeration system where the strength of the system actually increase, these decrease. 5.2.2 Six building conglomerations The following results are for the 6 building conglomeration systems. The results are similar for the 6 building conglomerations as for the 3 building conglomerations. Each of the different conglomerations negatively influenced the standard 3 storey building’s response. All of the conglomerations reduce the ultimate strength of the building and some also reduce the ultimate displacement obtained. There are a few outliers as seen in Figure 5.6 below. One system observed a very low acceleration at its ultimate displacement, clearly smaller than 80% of the highest value. This is the result of the convergence being too large for that particular model. The other two outliers are caused by an very large displacement of the system after the first iteration. This occurs in one of the 9 building conglomerations as well and is discussed in more detail later. L24_H3_F1 Percent Difference Monotonic Pushover Curves 6 * L24 H3 F1 - C1 - B1 50% 0.6 6 * L24 H3 F1 - C1 - B4 0.4 0.50 1.00 1.50 2.00 2.50 6 * L24 H3 F1 - C2 - B1 6 * L24 H3 F1 - C2 - B4 -50% 6 * L24 H3 F1 - C1 - B4 w/ external F2 -100% 6 * L24 H3 F1 - C1 - B6 w/ external F2 -150% 0.2 Acceleration (g) Percent Difference in Acceleration 0% 0.00 0.0 0.00 0.50 1.00 1.50 2.00 2.50 -0.2 6 * L24 H3 F1 - C2 - B4 w/ external F2 -200% 6 * L24 H3 F1 - C2 - B6 w/ external F2 6 * L24 H3 F1 - C1 - B1 w/ internal F2 -250% -0.4 -0.6 Displacement (cm) Displacement (cm) Figure 5.40. 6 building conglomerations results 51 Chapter 5. Simple Conglomeration A - 6 Buildings - L24 H3 F1 – Pounding Connection B - 6 Buildings - L24 H3 F1 – Full Connection Figure 5.41. 6 building conglomeration models The failure mode is similar between the standard 3 storey building conglomerations when comparing the pounding and full connections as seen above. Because all of the buildings have wood floors acting as a weak diaphragm, the interior wall observes the largest displacements of the system. A – 6 Buildings - L24 H3 F1 – Pounding Connection w/ external F2 on the left B - 6 Buildings - L24 H3 F1 – Full Connection w/ external F2 on the left 52 Chapter 5. Simple Conglomeration C - 6 Buildings - L24 H3 F1 – Pounding Connection w/ internal F2 in the centre D - 6 Buildings - L24 H3 F1 – Full Connection w/ internal F2 in the centre Figure 5.42. 6 building conglomeration models The effects of the concrete building on the behaviour of the conglomeration are similar for the 6 building systems as for the 3 building systems. The concrete floors distribute the inertial forces from the interior walls to the exterior walls as seen most clearly in the plan views for the full building connections. These show that all three walls have approximately the same displacement at failure. The concrete floor building is not as effective at distributing the loads between walls through a pounding connection as through a full connection. This observation is similar to that made for the 3 building conglomerations. The pounding connection systems also depict a separation of buildings. 5.2.3 Nine building conglomerations The following results are for the 9 building conglomeration systems. The results for the 9 building conglomerations are very similar to those for the other conglomerations. Clearly the size of the conglomeration is not a major factor in determining the influence on a building. The important factors appear to be whether the system has pounding or full building connections. Pounding connections are more detrimental to the standard building’s response. For larger conglomerations, the full connection also appears to have a negative effect on the building’s response. 53 Chapter 5. Simple Conglomeration L24_H3_F1 Percent Difference Monotonic Pushover Curves 9 * L24 H3 F1 - C1 - B1 50% 0.6 9 * L24 H3 F1 - C1 - B5 0.4 0.50 1.00 1.50 2.00 2.50 9 * L24 H3 F1 - C2 - B1 9 * L24 H3 F1 - C2 - B5 -50% 9 * L24 H3 F1 - C1 - B5 w/ external F2 -100% 9 * L24 H3 F1 - C1 - B9 w/ external F2 -150% 0.2 Acceleration (g) Percent Difference in Acceleration 0% 0.00 0.0 0.00 0.50 1.00 1.50 2.00 2.50 -0.2 9 * L24 H3 F1 - C2 - B5 w/ external F2 -200% 9 * L24 H3 F1 - C2 - B9 w/ external F2 9 * L24 H3 F1 - C1 - B1 w/ internal F2 -250% -0.4 -0.6 Displacement (cm) Displacement (cm) Figure 5.43. 9 building conglomerations results Similar to the 6 building conglomerations earlier, the 9 building conglomeration results contain a few uncharacteristic responses. The full connection between all wood buildings also experiences an initial large displacement under the first step of the analysis as does the 6 building conglomerations with the same setup. Likewise, the conglomeration with an external concrete floor building experiences a very large final displacement at a level of acceleration lower than 80% of the highest acceleration, similar to the same system type for the 6 building conglomerations. The wall elevations for the 9 building conglomerations are not presented in the following figures because they are very small due to their long length. The plan views illustrate similar trends as seen for in the 6 building systems. A - 9 Buildings - L24 H3 F1 – Pounding Connection B - 9 Buildings - L24 H3 F1 – Full Connection Figure 5.44. 9 building conglomeration models A - 9 Buildings - L24 H3 F1 – Pounding Connection w/ external F2 on the left B - 9 Buildings - L24 H3 F1 – Full Connection w/ external F2 on the left C - 9 Buildings - L24 H3 F1 – Pounding Connection w/ internal F2 in the centre 54 Chapter 5. Simple Conglomeration D - 9 Buildings - L24 H3 F1 – Full Connection w/ internal F2 in the centre Figure 5.45. 9 building conglomeration models The most important note to make about the 9 building conglomerations is that the wood floor buildings begin to develop the global behaviour as the individual buildings due to the long length of the system. As seen in the plan view for group B, the building on the end of the conglomeration has larger displacements at the centre wall than the outer walls. The concrete floor building on the far left, however, has very similar displacements for each of the walls. This means that when the conglomeration becomes longer, the benefit of having a rigid floor diaphragm is lost for the overall system. This leaves only negative effects from the additional weight from the concrete floors being transferred throughout the system. 5.2.4 Pounding connections, no concrete floor buildings The following results are for the pounding connection conglomeration systems without any concrete floor buildings in the conglomeration. All of the conglomerations caused a decrease in the highest acceleration obtained by the standard building in its response. There is no clear difference between the size of the conglomeration or position within a conglomeration in affecting standard building’s response. L24_H3_F1 Percent Difference Monotonic Pushover Curves 3 * L24 H3 F1 - C1 - B1 40% 0.6 6 * L24 H3 F1 - C1 - B1 20% 0.4 3 * L24 H3 F1 - C1 - B2 0.50 1.00 1.50 2.00 2.50 0.2 6 * L24 H3 F1 - C1 - B4 -20% 9 * L24 H3 F1 - C1 - B5 -40% Acceleration (g) Percent Difference in Acceleration 9 * L24 H3 F1 - C1 - B1 0% 0.00 0.0 0.00 0.50 1.00 1.50 2.00 2.50 -0.2 -60% -0.4 -80% -0.6 -100% Displacement (cm) Displacement (cm) Figure 5.46. Pounding connections, no concrete floor buildings 5.2.5 Full connections, no concrete floor buildings The following results are for the full connection conglomeration systems without any concrete floor buildings in the conglomeration. For the 3 building conglomeration, the capacity of the standard building increases due to the interaction with the other buildings. Both the ultimate displacement and maximum acceleration increase for this system. In this case, the full connection essentially joins the buildings together which increases the capacity of the 55 Chapter 5. Simple Conglomeration standard building. This is similar to the effect observed in a few of the coupled systems from the previous chapter. Longer conglomerations observe a more detrimental effect from the influence of adjacent buildings. For both the 6 and 9 building conglomerations, the standard building decreases in strength. This is due to the fact that the full connection between buildings is not strong enough to link the buildings together over longer conglomerations. As can be seen in Figure 5.13 below, a few of the full connection row conglomerations have an unusual pushover curve. This curve is caused by a discrepancy within these files. The first step in the pushover analysis causes a jump to a large displacement. Figure 5.14 shows the models at the beginning of the analysis and after one step. Clearly the building exhibits large displacements after the first step of the analysis. Throwing out this data, we obtain Figure 5.15 below. This only occurred in systems without concrete floors. L24_H3_F1 Percent Difference Monotonic Pushover Curves 3 * L24 H3 F1 - C2 - B1 50% 0.8 6 * L24 H3 F1 - C2 - B1 0.6 0% 0.00 0.50 1.00 1.50 2.00 2.50 9 * L24 H3 F1 - C2 - B1 0.2 6 * L24 H3 F1 - C2 - B4 -100% 9 * L24 H3 F1 - C2 - B5 Acceleration (g) Percent Difference in Acceleration 0.4 3 * L24 H3 F1 - C2 - B2 -50% 0.0 0.00 0.50 1.00 1.50 2.00 2.50 -0.2 -150% -0.4 -200% -0.6 -0.8 -250% Displacement (cm) Displacement (cm) Figure 5.47. Full connections, no concrete floor buildings At rest After first step Figure 5.48. Model 56 Chapter 5. Simple Conglomeration L24_H3_F1 Percent Difference Monotonic Pushover Curves 3 * L24 H3 F1 - C2 - B1 40% 0.8 20% 0.6 3 * L24 H3 F1 - C2 - B2 0.50 1.00 1.50 2.00 2.50 0.2 -20% 9 * L24 H3 F1 - C2 - B5 -40% Acceleration (g) Percent Difference in Acceleration 0.4 0% 0.00 0.0 0.00 0.50 1.00 1.50 2.00 2.50 -0.2 -60% -0.4 -80% -0.6 -0.8 -100% Displacement (cm) Displacement (cm) Figure 5.49. Full connections, no concrete floor buildings without unusual pushover curves 5.2.6 Pounding connection, external concrete floor building The following results are for the pounding connection conglomeration systems with a building with concrete floors on the far left side of the conglomeration. All of the conglomerations caused a decrease in the highest acceleration obtained by the standard building in its response. The effect of a heavier floor system appears to be detrimental to the other buildings within a conglomeration where the buildings are connected by pounding connections. L24_H3_F1 Percent Difference Monotonic Pushover Curves 3 * L24 H3 F1 - C1 - B3 w/ external F2 50% 0.6 6 * L24 H3 F1 - C1 - B6 w/ external F2 0.4 9 * L24 H3 F1 - C1 - B9 w/ external F2 0.50 1.00 1.50 2.00 2.50 3 * L24 H3 F1 - C1 - B2 w/ external F2 -50% 6 * L24 H3 F1 - C1 - B4 w/ external F2 9 * L24 H3 F1 - C1 - B5 w/ external F2 -100% 0.2 Acceleration (g) Percent Difference in Acceleration 0% 0.00 0.0 0.00 0.50 1.00 1.50 2.00 2.50 -0.2 -150% -0.4 -0.6 -200% Displacement (cm) Displacement (cm) Figure 5.50. Pounding connection, external concrete floor building 5.2.7 Full connection, external concrete floor building The following results are for the full connection conglomeration systems with a building with concrete floors on the far left side of the conglomeration. All of the conglomerations caused a decrease in the highest acceleration and ultimate displacement obtained by the standard building in its response. The effect of a heavier floor system appears to be detrimental to the other buildings even though, as seen before, the presence of a stiffer diaphragm helps distribute loads to the exterior walls and relieve the interior one. The overall effect is that the 57 Chapter 5. Simple Conglomeration weight of the concrete floors transferred through the conglomeration decreases the capacity of the buildings adjacent to it. L24_H3_F1 Percent Difference Monotonic Pushover Curves 3 * L24 H3 F1 - C2 - B3 w/ external F2 0% 0.00 0.6 0.50 1.00 1.50 2.00 2.50 6 * L24 H3 F1 - C2 - B6 w/ external F2 -10% 0.4 9 * L24 H3 F1 - C2 - B9 w/ external F2 -30% 3 * L24 H3 F1 - C2 - B2 w/ external F2 -40% 6 * L24 H3 F1 - C2 - B4 w/ external F2 -50% 9 * L24 H3 F1 - C2 - B5 w/ external F2 -60% 0.2 Acceleration (g) Percent Difference in Acceleration -20% 0.0 0.00 0.50 1.00 1.50 2.00 2.50 -0.2 -70% -80% -0.4 -90% -0.6 -100% Displacement (cm) Displacement (cm) Figure 5.51. Full connection, external concrete floor building 5.2.8 Pounding connection, internal concrete floor building The following results are for the pounding connection conglomeration systems with a building with concrete floors at the centre of the conglomeration. Note that only external building positions are considered for the standard 3 storey building because the building with concrete floors occupies the centre most position of each conglomeration. The effects of the conglomeration and the presence of the concrete floors are similar to the previous systems. The standard building decreases in capacity, especially when acted upon by the heavier building and the rest of the conglomeration. L24_H3_F1 Percent Difference Monotonic Pushover Curves 3 * L24 H3 F1 - C1 - B1 w/ internal F2 50% 0.6 6 * L24 H3 F1 - C1 - B1 w/ internal F2 0.50 1.00 1.50 2.00 2.50 0.4 9 * L24 H3 F1 - C1 - B1 w/ internal F2 -50% 0.2 Acceleration (g) Percent Difference in Acceleration 0% 0.00 -100% 0.0 0.00 -150% -0.2 -200% -0.4 0.50 1.00 1.50 2.00 2.50 -0.6 -250% Displacement (cm) Displacement (cm) Figure 5.52. Pounding connection, internal concrete floor building 58 Chapter 5. Simple Conglomeration 5.2.9 Full connection, internal concrete floor building The following results are for the full connection conglomeration systems with a building with concrete floors at the centre of the conglomeration. Note that only external building positions are considered for the standard 3 storey building because the building with concrete floors occupies the centre most position of each conglomeration. The effects of the conglomeration and the presence of the concrete floors are similar to the pounding system with the same orientation above. The standard building decreases in capacity both in acceleration and displacement. L24_H3_F1 Percent Difference Monotonic Pushover Curves 3 * L24 H3 F1 - C2 - B1 w/ internal F2 0% 0.00 0.6 0.50 1.00 1.50 2.00 2.50 6 * L24 H3 F1 - C2 - B1 w/ internal F2 -10% 0.4 9 * L24 H3 F1 - C2 - B5 w/ internal F2 -30% 0.2 Acceleration (g) Percent Difference in Acceleration -20% -40% -50% -60% 0.0 0.00 0.50 1.00 1.50 2.00 2.50 -0.2 -70% -0.4 -80% -0.6 -90% Displacement (cm) Displacement (cm) Figure 5.53. Full connection, internal concrete floor building 5.3 Discussion Except for the fully connected buildings in the 3 building row conglomeration, the influence of adjacent buildings appears to be negative. In only one instance did the strength of the building remain the same, and that was the fully connected buildings in the row conglomeration with all of them having wood floors. Position does not appear to play much of a role. The decrease in capacity of the buildings appears to be roughly the same percentage regardless of position within the row conglomeration. Adding a heavier building to the row conglomeration also does not appear to make a more significant impact on the building’s overall response, however, in certain cases it does cause for the inertial forces to distribute between the three walls more effectively. 59 Chapter 6. Conclusions 6. CONLCUSIONS These results are to be used to gain a general understanding of building interaction between masonry systems. Five factors have been considered on a preliminary level: building height, wall length, floor type, inter-building connections, and position within a conglomeration. A more in depth study of variable would have to be pursued before levels of design are possible to be obtained. This study does suggest that the most important parameters in understanding building interaction are the building’s height and the inter-building connection. Only the latter parameter is included in the conglomeration study of the previous chapter while the former is included in the coupled system analysis. 6.1 Further Study Future study is needed in order to better quantify the effects of inter-building interaction within a conglomeration. This study indicates that the most important parameters to consider in future studies are the buildings’ heights and the inter-building connections. These conclusions are simply drawn from the parameters studied. Other parameters need to be studied in order to fully understand the inter-building relationship. Torsion, differential ground motions, and different building materials are all very important topics that this study does not cover. When these other parameters are considered, the importance of floor systems and building position may increase. Eventually studies of different building materials may provide useful coefficients to capture the effect of inter-building reaction on a city-wide scale. This would ultimately allow for better hazard estimates for future earthquakes. 60 References REFERENCES Abrams, D. P. [2001] “Performance-based engineering concepts for unreinforced masonry building structures,” Progress in Structural Engineering and Materials; Vol. 3, pp. 38-56. Augusti, G., Ciampoli, M. [2000] “Heritage buildings and seismic reliability,” Progress in Structural Engineering and Materials; Vol. 2, pp. 225-237. Benedetti, D., Benzoni, G.M. [1991] “Identification of equivalent structural schemes for coupled systems,” Earthquake Engineering and Structural Dynamics; Vol. 20, No. 4, pp. 317-333. Binda, L., Anzani, A. [1998] “Rehabilitation and reuse of historic masonry buildings in Europe,” Progress in Structural Engineering and Materials; Vol. 1, No. 3, pp. 217-278. Binda, L., Saisi, A. [2005] “Research on historic structures in seismic areas in Italy,” Progress in Structural Engineering and Materials; Vol. 7, pp. 71-85. Borri, A., Cangi, G. [2004] “Vulnerabilità ed interventi di prevenzione sismica nei centri storici umbri dell’alta val tiberina,” Proceedings of 9th Congresso Nazionale “L’ingegneria Sismic in Italia,” Genoa, Italy. Borri, A., De Maria, D., Piccarreta, M. [2004] “Osservazione dei danni negli edifici di aggregazioni storiche dell’Umbria,” Proceedings of 9th Congresso Nazionale “L’ingegneria Sismic in Italia,” Genoa, Italy. Cattari, S., Curti, E., Giovinazzi, S., Lagomarsino, S., Parodi, S., Penna, A. [2004] “Un modello meccanico per l’analisi di vulnerabilità del costruito in muratura a scala urbana,” Proceedings of 9th Congresso Nazionale “L’ingegneria Sismic in Italia,” Genoa, Italy. Dialer, C. P. [2002] “Typical masonry failures and repairs: a German Engineer’s view,” Progress in Structural Engineering and Materials; Vol. 4, pp. 332-339. D’Ayala D., Spence R., Oliveira C., Silva P. [1996] ”Vulnerability of buildings in historic town centres: a limit-state approach,” Proceedings of XI World Conference on Earthquake Engineering, Mexico. Galasco, A., Lagomarsino, S., Penna, A., Resemini, S. [2004] “Non-linear seismic analysis of masonry structures,” Proceedings of 13th World Conference on Earthquake Engineering, Vancouver, Canada. Jankowski, R. [2006] “Analytical expression between the impact damping ratio and the coefficient of restitution in the non-linear viscelastic model of structural pounding,” Earthquake Engineering and Structural Dynamics; Vol. 35, pp. 517-524. 61 References Lourenço P.B., [2002] “Computations on historic masonry structures,” Progress in Structural Engineering and Materials; Vol. 4, pp. 301-319. Magenes, G., [2006] “Masonry building design in seismic areas: recent experiences and prospects from a European standpoint,” First European Conference on Earthquake Engineering and Seismology; keynote address K9. Muthukumar, S., DesRoches, R. [2006] “A Hertz contact model with non-linear damping for pounding simulation,” Earthquake Engineering and Structural Dynamics; Vol. 35, pp. 811-828. Penelis, G. G. [2002] “Strucutural restoration of historical buildings in seismic areas,” Progress in Structural Engineering and Materials; Vol. 4, pp. 64-73. Rush, A., Leafer, D. [2004] “Physical and chemical properties of pre-regulated American cements,” Proceedings of 4th International Seminar on Structural Analysis of Historical Constructions, Padua, Italy. Stavroulakis, G., Abdalla, K. [1991] “Contact between adjacent structures,” Journal of Structural Engineering; Vol. 117, No. 10, pp. 2838-2850. Tobriner, S., Comerio, M., Green, M. [1997] “Reconnaissance report on the Umbria-Marche, Italy earthquakes of 1997,” EERI Special Earthquake Report; pp 1-12. Westermo, B.D. [1989] “The dynamics of interstructural connection to prevent pounding,” Journal Earthquake Engineering and Structural Dynamics; Vol. 18, pp. 687-699. Zhang, W. S., Xu, Y. L. [1999] “Dynamic characteristics and seismic reponse of adjacent buildings linked by discrete dampers,” Earthquake Engineering and Structural Dynamics; Vol. 28, pp. 11631185. 62 Appendix A – Single Building Results APPENDIX A – SINGLE BUILDING RESULTS This section contains results from pushover analysis for single buildings in greater detail than presented in the previous chapters. A.1 Monotonic Pushover Results In general, the individual buildings perform as expected. The shortest buildings reach the highest levels of acceleration and the tallest have the largest displacements, with a few exceptions. Buildings with concrete floors tend to have lower levels of acceleration as do buildings with flexible walls. One important observation to note is that buildings with wood floors tend to have larger displacements than those with concrete. The reason is because of weak diaphragm action. This cause most of the load to be concentrated at the interior wall which then fails first and brings the exterior walls with it. This weak diaphragm action remains in the study because of the importance of properly representing historical buildings. A concentration of inertial forces or the inability to properly distribute them between the available walls causes the buildings to be weaker than they would be otherwise. Figure 3.6 shows the three parallel lateral resisting walls just before failure for buildings with wood floors. As can be clearly seen in this figure, the interior wall fails first and causes the exterior ones to fail afterwards. The results from monotonic pushover analysis are provided below. Note that the displacement axis for the negative monotonic pushover curves has been changed to the positive displacement axis for better comparison purposes. A.1.1 Height The effect of height on the global response of a building is as expected. For a given level of displacement, the acceleration required to reach that displacement is greater for the shorter buildings and lower for the taller buildings with largest difference between the 1 storey building and the 4 storey building. The results are divided by wall type and floor type. A general pushover curve summarizes the results for the difference combinations by comparing the different building heights under that combination to one another. The following 4 graphs after the large monotonic pushover curve provide the percent difference between the different buildings for better comparison purposes. A1 Appendix A – Single Building Results Table A.7. Legend for height comparison 1 Storey 2 Stories 3 Stories 4 Stories A2 Appendix A – Single Building Results 0.8 0.6 0.4 Acceleration (g) 0.2 0.0 0.0 1.0 2.0 3.0 4.0 5.0 6.0 -0.2 -0.4 -0.6 -0.8 Displacement (cm) Figure A.54. Monotonic pushover curves: flexible walls & wood floors 150% 0% 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 -20% 100% Percent Difference in Acceleration Percent Difference in Acceleration -40% -60% -80% -100% -120% -140% 50% 0% 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 0.6 0.7 0.8 0.9 -50% -160% -100% -180% -200% -150% Displacement (cm) Displacement (cm) 1 story base building 2 storey base building 200% 200% 180% 160% 100% 50% 0% 0.0 0.1 0.2 0.3 0.4 0.5 0.6 -50% 0.7 0.8 0.9 Percent Difference in Acceleration Percent Difference in Acceleration 150% 140% 120% 100% 80% 60% 40% -100% 20% 0% -150% 0.0 Displacement (cm) 3 story base building 0.1 0.2 0.3 0.4 0.5 Displacement (cm) 4 story base building Figure A.55. Constants: flexible walls & wood floors A3 Appendix A – Single Building Results 0.4 0.3 0.2 Acceleration (g) 0.1 0.0 0.0 0.5 1.0 1.5 2.0 2.5 -0.1 -0.2 -0.3 -0.4 -0.5 Displacement (cm) Figure A.56. Monotonic pushover curves: flexible walls & concrete floors 50% 150% 100% 0% 0.1 0.2 0.3 0.4 0.5 0.6 0.7 Percent Difference in Acceleration Percent Difference in Acceleration 0.0 -50% -100% -150% 50% 0% 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.5 0.6 0.7 -50% -100% -150% -200% -200% -250% -250% Displacement (cm) Displacement (cm) 1 story base building 2 storey base building 250% 200% 150% Percent Difference in Acceleration 50% 0% 0.0 0.1 0.2 0.3 0.4 -50% -100% 0.5 0.6 0.7 Percent Difference in Acceleration 200% 100% 150% 100% 50% -150% -200% 0% 0.0 -250% Displacement (cm) 3 story base building 0.1 0.2 0.3 0.4 Displacement (cm) 4 story base building Figure A.57. Constants: flexible walls & concrete floors A4 Appendix A – Single Building Results 1.5 1.0 Acceleration (g) 0.5 0.0 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 -0.5 -1.0 -1.5 Displacement (cm) Figure A.58. Monotonic pushover curves: rigid walls & wood floors 150% 20% 0% 0.0 0.1 0.1 0.2 0.2 0.3 0.3 0.4 0.4 100% 0.5 Percent Difference in Acceleration Percent Difference in Acceleration -20% -40% -60% -80% -100% -120% -140% 50% 0% 0.0 0.1 0.1 0.2 0.2 0.3 0.3 0.4 0.4 0.5 -50% -100% -160% -150% -180% Displacement (cm) Displacement (cm) 1 story base building 2 storey base building 200% 180% 160% 150% 50% 0% 0.0 0.1 0.1 0.2 0.2 0.3 -50% 0.3 0.4 0.4 0.5 Percent Difference in Acceleration Percent Difference in Acceleration 140% 100% 120% 100% 80% 60% 40% 20% -100% 0% 0.0 -150% Displacement (cm) 3 story base building 0.1 0.1 0.2 0.2 0.3 0.3 0.4 0.4 0.5 Displacement (cm) 4 story base building Figure A.59. Constants: rigid walls & wood floors A5 Appendix A – Single Building Results 1.5 1.0 Acceleration (g) 0.5 0.0 0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 -0.5 -1.0 -1.5 Displacement (cm) Figure A.60. Monotonic pushover curves: rigid walls & concrete floors 0% 150% 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 -20% 100% Percent Difference in Acceleration Percent Difference in Acceleration -40% -60% -80% -100% -120% -140% 50% 0% 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 -50% -100% -160% -150% -180% -200% -200% Displacement (cm) Displacement (cm) 1 story base building 2 storey base building 200% 200% 180% 150% 50% 0% 0.0 0.1 0.2 0.3 0.4 0.5 -50% 0.6 0.7 0.8 0.9 Percent Difference in Acceleration Percent Difference in Acceleration 160% 100% 140% 120% 100% 80% 60% 40% -100% 20% 0% 0.0 -150% Displacement (cm) 3 story base building 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 Displacement (cm) 4 story base building Figure A.61. Constants: rigid walls & concrete floors A6 Appendix A – Single Building Results A.1.2 Wall and floor stiffness Below are a serious of graphs depicting the results for monotonic pushover analysis comparing the effects of wall and floor stiffness on the response of a building. As can be expected, wall stiffness was more important to the difference of a building response than floor stiffness. Another important note to consider is the level of change of wall stiffness versus the level of change of floor stiffness. The results are divided by building height. A general pushover curve summarizes the results for the difference combinations by comparing the different building wall types and floor types under that combination to one another. The following 4 graphs after the large monotonic pushover curve provide the percent difference between the different buildings for better comparison purposes. Table A.8. Legend for wall and floor comparison Flexible walls, Wood floors Flexible walls, Concrete floors Rigid walls, Wood floors Rigid walls, Concrete floors A7 Appendix A – Single Building Results 1.5 1.0 Acceleration (g) 0.5 0.0 0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 -0.5 -1.0 -1.5 Displacement (cm) Figure A.62. Monotonic pushover curves: 1 storey buildings 140% 140% 120% 120% 80% 60% 40% 20% 0% 0.0 0.1 0.1 0.2 0.2 0.3 0.3 0.4 0.4 0.5 -20% Percent Difference in Acceleration Percent Difference in Acceleration 100% 100% 80% 60% 40% 20% -40% 0% 0.0 -60% 0.1 0.1 0.2 0.3 0.3 0.4 0.4 0.5 Displacement (cm) Displacement (cm) Flexible walls & Wood floors base building Flexible walls & Concrete floors base building 60% 80% 40% 60% 20% 40% 0% 0.0 0.1 0.1 0.2 0.2 0.3 0.3 0.4 -20% -40% -60% -80% 0.4 0.5 Percent Difference in Acceleration Percent Difference in Acceleration 0.2 -20% -80% 20% 0% 0.0 0.1 0.1 0.2 0.2 0.3 0.3 0.4 0.4 0.5 -20% -40% -60% -100% -80% -120% -100% -120% -140% Displacement (cm) Displacement (cm) Rigid walls & Wood floors base building Rigid walls & Concrete floors base building Figure A.63. Constant: 1 storey buildings A8 Appendix A – Single Building Results 0.8 0.6 0.4 Acceleration (g) 0.2 0.0 0.0 1.0 2.0 3.0 4.0 5.0 6.0 -0.2 -0.4 -0.6 -0.8 Displacement (cm) Figure A.64. Monotonic pushover curves: 2 storey buildings 120% 100% 100% 80% 80% Percent Difference in Acceleration Percent Difference in Acceleration 120% 60% 40% 20% 0% 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 60% 40% 20% 0% 0.9 0.0 -20% 0.1 0.2 0.3 -40% 0.5 0.6 0.7 0.8 0.9 -40% Displacement (cm) Displacement (cm) Flexible walls & Wood floors base building Flexible walls & Concrete floors base building 40% 40% 20% 20% 0% 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 -20% -40% -60% -80% -100% 0.8 0.9 Percent Difference in Acceleration Percent Difference in Acceleration 0.4 -20% 0% 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 -20% -40% -60% -80% -100% -120% -120% Displacement (cm) Rigid walls & Wood floors base building Displacement (cm) Rigid walls & Concrete floors base building Figure A.65. Constant: 2 storey buildings A9 Appendix A – Single Building Results Monotonic Pushover Curves 0.6 0.4 Acceleration (g) 0.2 0.0 0.00 1.00 2.00 3.00 4.00 5.00 6.00 -0.2 -0.4 -0.6 Displacement (cm) Figure A.66. Monotonic pushover curves: 3 storey buildings 120% 120% 100% Percent Difference in Acceleration Percent Difference in Acceleration 100% 80% 60% 40% 20% 80% 60% 40% 20% 0% 0.0 0% 0.0 0.2 0.4 0.6 0.8 1.0 1.2 0.2 0.4 0.6 0.8 1.0 1.2 1.4 -20% 1.4 -20% -40% Displacement (cm) Displacement (cm) Flexible walls & Wood floors base building Flexible walls & Concrete floors base building 40% 20% 20% 0% 0.2 0.4 0.6 0.8 1.0 1.2 1.4 Percent Difference in Acceleration Percent Difference in Acceleration 0.0 -20% -40% -60% -80% -100% 0% 0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 -20% -40% -60% -80% -100% -120% -120% Displacement (cm) Displacement (cm) Rigid walls & Wood floors base building Rigid walls & Concrete floors base building Figure A.67. Constant: 3 storey buildings A10 Appendix A – Single Building Results 0.5 0.4 0.3 Acceleration (g) 0.2 0.1 0.0 0.0 1.0 2.0 3.0 4.0 5.0 6.0 -0.1 -0.2 -0.3 -0.4 -0.5 Displacement (cm) Figure A.68. Monotonic pushover curves: 4 storey buildings 150% 120% 100% 100% 60% 40% 20% 0% 0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 -20% Percent Difference in Acceleration Percent Difference in Acceleration 80% 50% 0% 0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 -50% -40% -60% -80% -100% Displacement (cm) Displacement (cm) Flexible walls & Wood floors base building Flexible walls & Concrete floors base building 20% 150% 0% 0.2 0.4 0.6 0.8 1.0 1.2 1.4 100% Percent Difference in Acceleration Percent Difference in Acceleration 0.0 -20% -40% -60% -80% -100% 50% 0% 0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 -50% -100% -120% -140% -150% Displacement (cm) Rigid walls & Wood floors base building Displacement (cm) Rigid walls & Concrete floors base building Figure A.69. Constant: 4 storey buildings A11 Appendix A – Single Building Results A.2 Cyclic Pushover Results A general pattern is noticeable in the results for cyclic pushover analysis. For the flexible wall buildings, the hysteretic loops tend to be narrower than for the rigid wall buildings. This means that the energy dissipation was also less for these buildings. This makes sense because the flexible buildings with shorter walls tend to exhibit the rocking mechanism and toe crushing effect which dissipates less energy than the shear sliding mechanism. The longer, more rigid wall buildings tend to exhibit the shear sliding mechanism leading to larger hysteretic loops. 0.40 1.00 0.80 0.30 0.60 0.20 0.40 -2.00 -1.50 -1.00 -0.50 0.00 0.00 0.50 1.00 1.50 2.00 -0.20 Acceleration (g) Acceleration (g) 0.10 0.20 -0.80 -0.60 -0.40 -0.20 0.00 0.00 0.20 0.40 0.60 0.80 1.00 1.20 0.60 0.80 1.00 -0.10 -0.40 -0.20 -0.60 -0.30 -0.80 -1.00 -0.40 Displacement (cm) Displacement (cm) -0.60 -0.40 L12_H1_F2 Flexible walls & Wood floors Flexible walls & Concrete floors 1.50 1.50 1.00 1.00 0.50 0.50 -0.20 0.00 0.00 0.20 0.40 0.60 Acceleration (g) Acceleration (g) L12_H1_F1 -1.00 -0.80 -0.60 -0.40 -0.20 0.00 0.00 -0.50 -0.50 -1.00 -1.00 -1.50 Displacement (cm) L24_H1_F1 Rigid walls & Wood floors 0.20 0.40 -1.50 Displacement (cm) L24_H1_F2 Rigid walls & Concrete floors Figure A.70. Cyclic pushover curves for 1 storey buildings A12 Appendix A – Single Building Results 0.50 0.40 0.40 0.30 0.30 0.20 0.20 -8.00 -6.00 -4.00 0.00 0.00 -2.00 2.00 4.00 6.00 -0.10 Acceleration (g) Acceleration (g) 0.10 0.10 -1.50 -1.00 -0.50 0.00 0.00 0.50 1.00 1.50 2.00 -0.10 -0.20 -0.20 -0.30 -0.30 -0.40 -0.40 -0.50 -0.50 Displacement (cm) Displacement (cm) -8.00 -6.00 L12_H2_F2 Flexible walls & Wood floors Flexible walls & Concrete floors 0.80 0.80 0.60 0.60 0.40 0.40 0.20 0.20 -4.00 -2.00 0.00 0.00 2.00 4.00 6.00 8.00 Acceleration (g) Acceleration (g) L12_H2_F1 -1.00 -0.80 -0.60 -0.40 -0.20 0.00 0.00 -0.20 -0.20 -0.40 -0.40 -0.60 -0.60 -0.80 0.20 0.40 0.60 0.80 1.00 1.50 2.00 2.50 -0.80 Displacement (cm) Displacement (cm) L24_H2_F1 L24_H2_F2 Rigid walls & Wood floors Rigid walls & Concrete floors -8.00 -6.00 -4.00 -2.00 0.30 0.30 0.20 0.20 0.10 0.10 0.00 0.00 2.00 4.00 6.00 8.00 Acceleration (g) Acceleration (g) Figure A.71. Cyclic pushover curves for 2 storey buildings -2.50 -2.00 -1.50 -1.00 -0.50 0.00 0.00 -0.10 -0.10 -0.20 -0.20 -0.30 Displacement (cm) L12_H3_F1 Flexible walls & Wood floors 0.50 1.00 -0.30 Displacement (cm) L12_H3_F2 Flexible walls & Concrete floors A13 -3.00 -2.00 -1.00 0.60 0.60 0.40 0.40 0.20 0.20 0.00 0.00 1.00 2.00 3.00 4.00 5.00 Acceleration (g) Acceleration (g) Appendix A – Single Building Results -2.00 -1.50 -1.00 -0.50 0.00 0.00 -0.20 -0.20 -0.40 -0.40 -0.60 0.50 1.00 1.50 2.00 -0.60 Displacement (cm) Displacement (cm) L24_H3_F1 L24_H3_F2 Rigid walls & Wood floors Rigid walls & Concrete floors -8.00 -6.00 -4.00 -2.00 0.25 0.25 0.20 0.20 0.15 0.15 0.10 0.10 0.05 0.05 0.00 0.00 2.00 4.00 6.00 8.00 -0.05 Acceleration (g) Acceleration (g) Figure A.72. Cyclic pushover curves for 3 storey buildings -2.50 -2.00 -1.50 -1.00 -0.50 0.00 0.00 0.50 1.00 1.50 2.00 -0.05 -0.10 -0.10 -0.15 -0.15 -0.20 -0.20 -0.25 -0.25 Displacement (cm) Displacement (cm) L12_H4_F1 L12_H4_F2 Flexible walls & Wood floors Flexible walls & Concrete floors 0.20 0.50 0.40 0.15 0.30 0.10 0.20 -5.00 -4.00 -3.00 -2.00 -1.00 0.00 0.00 1.00 -0.10 2.00 3.00 4.00 Acceleration (g) Acceleration (g) 0.05 0.10 -1.50 -1.00 -0.50 0.00 0.00 0.50 1.00 1.50 -0.05 -0.20 -0.10 -0.30 -0.40 -0.50 Displacement (cm) L24_H4_F1 Rigid walls & Wood floors -0.15 -0.20 Displacement (cm) L24_H4_F2 Rigid walls & Concrete floors Figure A.73. Cyclic pushover curves for 4 storey buildings A14 Appendix B – Coupled System Combinations APPENDIX B – COUPLED SYSTEM COMBINATIONS Below is the table of different coupled system combinations used in this study. Table B.9. Analysis coupled systems L12 H1 F1 L12 H1 F2 L12 H1 F1 L12 H1 F2 L12 H1 F1 L12 H1 F2 L12 H1 F1 L12 H1 F2 L12 H2 F1 L12 H2 F2 L12 H2 F1 L12 H2 F2 L12 H2 F1 L12 H2 F2 L12 H3 F1 L12 H3 F2 L12 H3 F1 L12 H3 F2 L12 H4 F1 L12 H4 F2 L12 H1 F1 L12 H1 F2 L12 H1 F1 L12 H1 F2 L12 H1 F1 L12 H1 F2 L12 H1 F1 L12 H1 F2 L12 H2 F1 L12 H2 F2 L12 H2 F1 L12 H2 F2 - L12 H1 F1 L12 H1 F2 L12 H2 F1 L12 H2 F2 L12 H3 F1 L12 H3 F2 L12 H4 F1 L12 H4 F2 L12 H2 F1 L12 H2 F2 L12 H3 F1 L12 H3 F2 L12 H4 F1 L12 H4 F2 L12 H3 F1 L12 H3 F2 L12 H4 F1 L12 H4 F2 L12 H4 F1 L12 H4 F2 L24 H1 F1 L24 H1 F2 L24 H2 F1 L24 H2 F2 L24 H3 F1 L24 H3 F2 L24 H4 F1 L24 H4 F2 L24 H1 F1 L24 H1 F2 L24 H2 F1 L24 H2 F2 - C2 C2 C2 C2 C2 C2 C2 C2 C2 C2 C2 C2 C2 C2 C2 C2 C2 C2 C2 C2 C2 C2 C2 C2 C2 C2 C2 C2 C2 C2 C2 C2 L12 H2 F2 L12 H2 F1 L12 H2 F2 L12 H2 F1 L12 H2 F2 L12 H3 F1 L12 H3 F2 L12 H3 F1 L12 H3 F2 L12 H4 F1 L12 H4 F2 L12 H1 F1 L12 H1 F2 L12 H1 F1 L12 H1 F2 L12 H1 F1 L12 H1 F2 L12 H1 F1 L12 H1 F2 L12 H2 F1 L12 H2 F2 L12 H2 F1 L12 H2 F2 L12 H2 F1 L12 H2 F2 L12 H2 F1 L12 H2 F2 L12 H3 F1 L12 H3 F2 L12 H3 F1 L12 H3 F2 L12 H3 F1 - L12 H2 F2 L12 H3 F1 L12 H3 F2 L12 H4 F1 L12 H4 F2 L12 H3 F1 L12 H3 F2 L12 H4 F1 L12 H4 F2 L12 H4 F1 L12 H4 F2 L24 H1 F1 L24 H1 F2 L24 H2 F1 L24 H2 F2 L24 H3 F1 L24 H3 F2 L24 H4 F1 L24 H4 F2 L24 H1 F1 L24 H1 F2 L24 H2 F1 L24 H2 F2 L24 H3 F1 L24 H3 F2 L24 H4 F1 L24 H4 F2 L24 H1 F1 L24 H1 F2 L24 H2 F1 L24 H2 F2 L24 H3 F1 - C1 C1 C1 C1 C1 C1 C1 C1 C1 C1 C1 C1 C1 C1 C1 C1 C1 C1 C1 C1 C1 C1 C1 C1 C1 C1 C1 C1 C1 C1 C1 C1 B1 Appendix B – Coupled System Combinations L12 H2 F1 L12 H2 F2 L12 H2 F1 L12 H2 F2 L12 H3 F1 L12 H3 F2 L12 H3 F1 L12 H3 F2 L12 H3 F1 L12 H3 F2 L12 H3 F1 L12 H3 F2 L12 H4 F1 L12 H4 F2 L12 H4 F1 L12 H4 F2 L12 H4 F1 L12 H4 F2 L12 H4 F1 L12 H4 F2 L24 H1 F1 L24 H1 F2 L24 H1 F1 L24 H1 F2 L24 H1 F1 L24 H1 F2 L24 H1 F1 L24 H1 F2 L24 H2 F1 L24 H2 F2 L24 H2 F1 L24 H2 F2 L24 H2 F1 L24 H2 F2 L24 H3 F1 L24 H3 F2 L24 H3 F1 L24 H3 F2 L24 H4 F1 L24 H4 F2 L12 H1 F1 L12 H1 F2 L12 H1 F1 L12 H1 F2 L12 H1 F1 L12 H1 F2 L12 H1 F1 L12 H1 F2 L12 H2 F1 - L24 H3 F1 L24 H3 F2 L24 H4 F1 L24 H4 F2 L24 H1 F1 L24 H1 F2 L24 H2 F1 L24 H2 F2 L24 H3 F1 L24 H3 F2 L24 H4 F1 L24 H4 F2 L24 H1 F1 L24 H1 F2 L24 H2 F1 L24 H2 F2 L24 H3 F1 L24 H3 F2 L24 H4 F1 L24 H4 F2 L24 H1 F1 L24 H1 F2 L24 H2 F1 L24 H2 F2 L24 H3 F1 L24 H3 F2 L24 H4 F1 L24 H4 F2 L24 H2 F1 L24 H2 F2 L24 H3 F1 L24 H3 F2 L24 H4 F1 L24 H4 F2 L24 H3 F1 L24 H3 F2 L24 H4 F1 L24 H4 F2 L24 H4 F1 L24 H4 F2 L12 H1 F1 L12 H1 F2 L12 H2 F1 L12 H2 F2 L12 H3 F1 L12 H3 F2 L12 H4 F1 L12 H4 F2 L12 H2 F1 - C2 C2 C2 C2 C2 C2 C2 C2 C2 C2 C2 C2 C2 C2 C2 C2 C2 C2 C2 C2 C2 C2 C2 C2 C2 C2 C2 C2 C2 C2 C2 C2 C2 C2 C2 C2 C2 C2 C2 C2 C1 C1 C1 C1 C1 C1 C1 C1 C1 L12 H3 F2 L12 H3 F1 L12 H3 F2 L12 H4 F1 L12 H4 F2 L12 H4 F1 L12 H4 F2 L12 H4 F1 L12 H4 F2 L12 H4 F1 L12 H4 F2 L24 H1 F1 L24 H1 F2 L24 H1 F1 L24 H1 F2 L24 H1 F1 L24 H1 F2 L24 H1 F1 L24 H1 F2 L24 H2 F1 L24 H2 F2 L24 H2 F1 L24 H2 F2 L24 H2 F1 L24 H2 F2 L24 H3 F1 L24 H3 F2 L24 H3 F1 L24 H3 F2 L24 H4 F1 L24 H4 F2 - L24 H3 F2 L24 H4 F1 L24 H4 F2 L24 H1 F1 L24 H1 F2 L24 H2 F1 L24 H2 F2 L24 H3 F1 L24 H3 F2 L24 H4 F1 L24 H4 F2 L24 H1 F1 L24 H1 F2 L24 H2 F1 L24 H2 F2 L24 H3 F1 L24 H3 F2 L24 H4 F1 L24 H4 F2 L24 H2 F1 L24 H2 F2 L24 H3 F1 L24 H3 F2 L24 H4 F1 L24 H4 F2 L24 H3 F1 L24 H3 F2 L24 H4 F1 L24 H4 F2 L24 H4 F1 L24 H4 F2 - C1 C1 C1 C1 C1 C1 C1 C1 C1 C1 C1 C1 C1 C1 C1 C1 C1 C1 C1 C1 C1 C1 C1 C1 C1 C1 C1 C1 C1 C1 C1 B2 Appendix C – Row Conglomeration Combinations APPENDIX C – ROW CONGLOMERATION COMBINATIONS Below is the table of different row conglomeration system combinations used in this study. Table C.10. Conglomeration list Number of Total Wall Number Floor Inter-Building Position of Building with Buildings Length (m) of Stories Type Connection Type Concrete Floors 24 24 24 24 24 24 24 24 24 24 24 24 24 24 24 24 24 24 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 6 6 6 6 6 6 9 9 9 9 9 9 Wood Wood Wood Wood Wood Wood Wood Wood Wood Wood Wood Wood Wood Wood Wood Wood Wood Wood Pounding Full Pounding Full Pounding Full Pounding Full Pounding Full Pounding Full Pounding Full Pounding Full Pounding Full Exterior building Exterior building Interior building Interior building Exterior building Exterior building Interior building Interior building Exterior building Exterior building Interior building Interior building C1 MSc Dissertation 2007 Seismic evaluation of masonry building conglomerations of adjacent structures Adam Rush