Table of Content S.No. Title Table of contents List of Figures List of Tables Acknowledgement 1 Introduction 1.1 General information 1.2 Layout of the report 2 Slab design 2.1 Flat plate design 2.2 Flat slab design 2.3 Slab with interior beam 3 Beam and Column design 3.1 General information 3.2 Edge beams 3.3 Interior beams 3.4 Corner columns 3.5 Edge column 3.6 Interior column 4 Staircase design 4.1 General information `4.2 Staircase design 5 Shear wall design 5.1 General information 5.2 Shear wall design for staircase 5.3 Shear wall design for elevator 6 Foundation design 6.1 General information 6.2 Footing under column 6.3 Footing under edge column 6.4 Footing under interior column 6.5 Combined footing under two adjacent corner edge columns 6.6 Staircase foundation 6.7 Shear wall foundation Page No 1 1 4 6 19 29 35 35 36 49 66 69 74 79 79 79 93 93 93 99 109 109 109 113 117 120 127 132 i 7 7.1 7.2 8 9 145 145 158 179 180 Retaining wall General information Green engineering Concrete material estimation References List of figures Figure No. Content Figure 1.1 Structural feature of the office building Page no. 1 Figure 1.2 2 The top view of the office building project using 25’x25’ panels Figure 2.1 The four types of slab for the office building Figure 2.2 The position of the use of the expansion joint on each floors Figure 2.3 The expansion joint (Source by Design Handbook: section 4 from Figure 2.4 Panel assignment Figure 2.5 Bars arrangement Figure 2.6 Shear check for flat slab with drop panel Figure 3.1 Panel load share that goes to an Edge Beam Figure 3.2 Glazing load dispersion diagram Figure 3.3 Loaded Frame on Axis ((A1-A2-A3-A4- A5) Figure 3.4 Loading and shear force diagram for beam A1-A2 of the flat plate floor Figure 3.5 Loading diagram (axis 1B-2B-3B-4B-5B) for the purpose of calculating additional moments due to self weight of beam Figure 3.6 Loading diagram (axis 1B-2B-3B-4B-5B) for the purpose of calculating shear in internal beams due to loads from slab Figure 3.7 Corner column attachment and section of beams attached to it Figure 3.8 Load transfer to an edge column Figure 3.9 Edge Column attachment to slabs/ beams in both directions Figure 3.10 Interior Column attachment to slabs/ beams 4 5 6 6 11 20 37 38 40 47 50 50 67 70 71 75 ii Figure 4.1 Figure 4.2 Figure 5.1 Figure 6.1 Figure 6.2 Figure 6.3 Figure 6.4 Figure 6.5 Figure 6.6 Figure 6.7 Figure 6.8 Figure 6.9 Figure 6.10 Figure 6.11 Figure 6.12 Figure 6.13 Figure 6.14 Figure 6.15 Figure 6.16 Figure 6.17 Figure 6.18 Figure 7.1 Figure 7.2 Figure 7.3 Figure 7.4 Figure 7.5 Figure 8.1 Figure 8.2 Figure 8.3 Figure 8.4 Figure 8.5 Building Plan View Staircase Plan View Shear force and bending moment due to wind load Footing load elements Corner Footing Bearing Pressure distribution Corner Footing Critical Sections: a) two way shear , b) one way shear and c) bending moment Edge footing Bearing Pressure distribution Edge Footing Critical Sections: a) two way shear , b) one way shear and c) bending moment Interior footing Bearing Pressure distribution Interior Footing Critical Sections: a) two way shear , b) one way shear and c) bending moment Common footing Bearing Pressure distribution Common Footing Critical Sections: a) two way shear , b) one way shear and c) bending moment Load at typical floor on wall Critical section for shear Critical section for shear Plan of shear wall & vertical forces acting on footing Plan of footing integrated with beams 1, 2, 3 showed in red hatch load & reactions on strip A load & reactions on Beam 1 load & reactions on Beam 2 load & reactions on Beam 3 Example of Retaining Wall Drainage system in retaining wall Free body of soil & pressure Footing Details Critical section for shear in toe Increases in Environmental Regulation Graphs on Emission in Industrial Typical Unitized Curtain Wall Systems Typical Unitized Curtain Wall System Assembled product Typical Unitized Curtain Wall System Air Vapor Barrier 79 81 94 109 110 110,112 114 114,115,116 118 118,119 121 123,124 127 129 130 132 134 134 137 139 141 145 146 147 151 155 163 164 169 169 171 iii Figure 8.6 Figure 8.7 Figure 8.8 Figure 8.9 Figure 8.10 Figure 8.11 Load Transfers Glass Panel Sizes at different floors Components of Roofing System Positive Drainage for healthy roots Fixing Method Scheme representation of Sewage Treatment Plant 174 175 177 178 178 180 List of Tables Table 2.1 Table 2.2 Table 3.1 Table 3.2 Table 3.3 Table 3.4 Table 3.5 Table 3.6 Table 3.7 Table 3.8 Table 3.9 Table 3.10 Table 4.1 Table 5.1 Table 7.1 Table 8.1 Table 8.2 Description of different types of panel Minimum thickness of slabs without interior beams (ACI table 9.5c) Summary of loading on Edge Beams Design Moments from SAP analysis output for frame on Axis ((A1-A2-A3- A4- A5) Design Moments for internal beams on axis 1B-2B3B-4B-5B Design Shear forces for internal beams on axis 1B2B-3B-4B-5B Corner column loading from frame analysis Design Loads Summary and Reinforcement provide for a Typical Corner Column Acting design loads before magnification for edge column Design Loads Summary and Reinforcement provided for a Typical Edge Column Acting Column Axial loads for an interior column Design Loads Summary and Reinforcement provided for a Typical interior Column Detailing of reinforcement Specification of elevators Vertical forces and moment acting at the toe of the footing Materials considered in green engineering Glass weight 7 10 39 40 51 51 66 69 71 74 75 77 88 102 149 161 169 iv Acknowledgment Our deepest gratitude goes to Prof Riyad S. Aboutah for his continuous and constructive advise and follow up. His successive advisories and comments were the pillars in our every step during the design process of the building and its comments. We are thankful to him for the fact that he has inspired and helped us know about the ACI Code, the concepts and ways of analysis and design of Shear walls, staircases, beams, column, foundations and retaining walls. We are also thankful to our peers who helped us in one way or another in bringing this project into the shape it has assumed now. v 1. Introduction This is a report for a design project of a three-story office building which is located in the city of Syracuse, New York. The main structure of the office building project is wholly made of reinforced concrete. The height of the building is 58 feet, and story heights of each floor are as specified in Figure 1.1 Each panel size of the building is 25’x 25’. Figure 1.1: Structural feature of the office building In addition, the building is designed for fire safety purpose by having two staircases situated at both corners of the building. For the convenient usage, the building is also comprised of two elevators and two freight elevator in the middle part of the building. Moreover, the outside parts of property include the parking lot, and retaining wall with the height of 10 feet run through the edge area of the property. This is illustrated in the figure 1.2 in the next page 1 Figure 1.2: The top view of the office building project using 25’x25’ panels The flooring system used in the design of the building is fashioned in such a way that the design project will give an opportunity to design different slab types. In line to this, slabs of flat plate type on the top floor, slab of flat slab type on the middle floor and slabs with interior beams on the first floor are used. On the top of the building along the peripheries there is a 1-ft high parapet wall. At the edges of the panels of staircase and elevators, shear wall will be incorporated for the design from the roof slab through ground slab. The thick square lines at the panel edges represent shear wall to be used. On the roof slab, a mechanical room is placed next to the two elevators in the same panel. Furthermore, as green engineering is becoming a big concern for the recent world environment, the design the building intends to include the aspects of the use of green roof at the top of the building (roof slab), glass panels placed outside on all sides of the building and Sewage Treatment Plant which gives the clean water as required for clean environment. In Building Sewage Treatment plant is fixed at the parking lot as it is a 2 modular system .Apart from that few finishes items are explained like waterproofing, Paints were its advantages to the environment are explained Throughout this project design a concrete strength capacity of 6000 psi and the steel strength capacity of 60000 psi are used. The design procedures are pertinent to those specified in the ACI-318 code and international building code design. Nonetheless to mention, aesthetics as an integral part of a building design, though not thoroughly dealt, has been tried to be incorporated. For this aspect, glass walling has been used as façade for the external part of the building. Material use estimation with a focus on concrete usage is also a part of the design project. The report is organized in such a manner that it will have flow when read. The second chapter is devoted to the design of slabs. Chapter three presents the design of beams and columns followed by design of stair case and shear wall in chapter four. In chapter six designs of foundations for the building and the shear walls is addressed. The green engineering and aesthetics part is included in chapter eight proceeded by retaining wall in chapter six. At the end comes the Concrete estimation followed by references. 3 2. Slabs Design 2.1 General information This office building uses the different type of design on each slab. Therefore, four types of slab will be used as specified by a plan requirement. These four slabs are designed using two-way slab systems, direct design method. A flat plate is used for a design for a roof slab which has supporting beams running over along the edge of the roof slab. Next, a flat slab is implemented for a design for the second floor. It also has supporting beams running over along the edge of the floor like the way it is done on the flat plate. However, they are different in that the flat slab makes a use of drop panels on the top of columns supporting the flat slab, resulting in a use of a less slab thickness than that of flat plate. For the first floor, the slab with interior beams is used. In this case, supporting beams at four sides of each panel squarely connect all the columns below the slab. Finally, the ground slab is designed to be used on the first floor of the building. The illustration of the slab design is shown below. Figure 2.1: The four types of slab for the office building 4 Moreover, expansion joint is provided for this building. Due to the temperatureproduced change, a potential impact is likely to occur to the office building. The utilization of the expansion joint brings a benefit for the office building in terms of the structural integrity and building serviceability. Before the concrete is placed, the expansion joint will be constructed by installing pre-formed or pre-molded elastic/resilient material. The thickness of such material to be incorporated at edge of slabs is half inch with the wideness of each slab types. Once the material has been inserted, the brass or bronze cover plate will be attached. The feature below shows the use of expansion joint at the interior edges of the office building on each floors and a feature example of this usage. Figure 2.2: The position of the use of the expansion joint on each floors 5 Figure 2.3: The expansion joint (Source by Design Handbook: section 4 from http://www.copper.org/homepage.html) 2.2 Flat plate Figure 2.4: Panel Assignment 6 The slab has been divided into panels (as indicated) for the purpose of design using the Direct Design Method as adopted by ACI Code. The axis coordinates have also been assigned to the top view of the building plan in order to show the direction of the particular strips to be considered in the calculation using excel sheet. The particular description of the panels are as detailed in the next page. Table 2.1: Description of different types of panel Panel 1 An exterior ( but not on the corner) panel in An exterior corner panel, both of its exterior which its exterior side is support on edge beam, edges are supported on edge beam which runs over the exterior columns Panel 2 Fulfills the requirements stated for direct design Fulfills the requirements stated for direct design method as per ACI Code method as per ACI Code Panel 3 Panel 4 An interior panel Fulfills the requirements stated for direct design method as per ACI Code An exterior panel like with support conditions like Panel 1 Does not meet, the requirement for the presence of at least three continuous panels direction 7 each Preliminary design of minimum column dimension In order to obtain a value of (ln) , the preliminary column dimension must be determined. The typical column considered is an interior column with the following tributary area. Assume the depth of slab to be 8 inches. Loads on this tributary area include snow load, live load, dead load, rain load. Rain load, RL = 62.5 psf Snow load, SL = 46.2 psf Roof Live load, Lr = 12.0 psf Dead load = 150 lb/ft3 *(8/12) ft = 100 psf Topping load = 20 psf Live load = 50 psf Finishing load = 20 psf Load combination (preliminary) This formula below is used to determine the combination of loads (ACI code 9.2) U = 1.2(DL+ FL + TL) +1.6*(LL+HL) + 0.5[max (Lr, SL,RL)] = 1.2(100 + 0 + 20) + 1.6(0 + 0) + 0.5*62.5 = 175.25 psf = 1.2(100 + 20 +0) + 1.6(50 + 0) + 0.5 (0) = 224 psf For flat plate U For flat slab U For slab with beams 8 U = 1.2(100 + 20 +0) + 1.6(50 + 0) + 0.5 (0) = 224 psf Load on Column Pu = 0.80 [0.85 (Ag -Ast) + Ast] = specified constant by code = 0.7 for tied columns = 6,000 psi = 60,000 psi Assume Ast is equal to 1.5% of Ag = 0.015 Ag For flat plate, P = 175.25 * (25’*25’) Pu = 1.5* P = 1.5 * 109.53 = 164.3 kips 164.3 = = 109.53 kips 0.7 *0.8 [0.85 * (6,000/1,000) * (Ag -0.015Ag) + (60,000/1,000) * 0.015Ag] Ag = 50 in2 Required column size = 7” x 7” For flat slab, Pu 368.7 = = 164.3 + 1.5[218 * (25’*25’)] = 368.7 kips 0.7 *0.8 [0.85 * (6,000/1,000) * (Ag -0.015Ag) + (60,000/1,000) * 0.015Ag] Ag = 111.15 in2 Column size = 11” x 11” For slab with beams, Pu 573.07 = = 368.7 + 1.5[190.25 * (25’*25’)] = 573.07 kips 0.7 *0.8 [0.85 * (6,000/1,000) * (Ag -0.015Ag) + (60,000/1,000) * 0.015Ag] Ag = 172.76 in2 Column size = 14” x 14” 9 As a result, the column size to be used is 14”x 14” in the design for flat plate, flat slab, and slab with beams. Depth requirements For the specified design concrete strength, as per ACI (table 9.5c) the minimum thickness required for flat slab and flat plate is Table 2.2: MINIMUM THICKNESS OF SLABS WITHOUT INTERIOR BEAMS (ACI table 9.5c) fy, psi Without drop panels Exterior panels With drop panels Interior Exterior panels Interior panels panels With edge Without With edge Without beams edge beams edge beams 60000 ln/33 ln/30 beams ln/33 ln/36 ln/33 ln/36 Minimum slab depth requirement for flat plate hmin = ln/33 ; ln = 25-(14’/12’) = 23.833’ = 23.833/33 = 0.722’ = 8.667” As a result, we try hmin = 9 inches. New design load for roof flat plate DL = 150 * (9/12) = 112.5 psf Ud = 175.25 + 1.2 (112.5 – 100) = 190.25 psf With the green roof load, an additional load of 30 psf is included. Ud = 190.25 + 1.2 (30) = 226.25 psf Static Moment for all panels of flat plate Mo = (Ud l1 ln2)/8 (ACI code 13-4) = 226.25 * 25 * [25-(14/12)2] / (8*1000) = 401.613 ft-k 10 Consider bar arrangement as follows Figure 2.5: Bars arrangement dx= depth for bars spanning in x-direction dy = depth for bar spanning in y-direction For an assumed j=0.925, compute trial area As, at a section of maximum moment, in this case (first interior negative column strip) with Mu = 210.85 ft-kips Shear check for flat plate Bars # 5 are used for reinforcement. dx = 9-3/4-(0.625/2) = 7.9375” dy = 7.9375 – 0.625 = 7.3125” dav = (7.9375+7.3125)/2 = 7.625” b0 = (2) (14” + 7.625”) + (2) (14”+7.625”) = 86.5” Vu ØVc = [(25’*25’)-{(14”+7.625”)/12}2]*(226.25/1000) = 140.827 kips = = Ø4 *b0 * d (0.85) * 4 * = 173.704 kips > 140.827 kips OK (ACI code 11-35) * (86.5) * (7.625)/1000 11 12 13 14 15 16 17 18 2.3 Flat Slab Depth requirement From table 2.2, minimum slab depth requirement for flat slab hmin = ln/36 ; ln = 25-(14’/12’) = 23.833’ = 23.833/36 = 0.662’ = 7.944” As a result, we try hmin = 8 inches. This thickness is the same as one assumed before. Therefore, Ud remains the same as one calculated from the preliminary design for a column dimension. Ud = 224 psf Static Moment for all panels of flat slab Mo = (Ud l1 ln2)/8 = 226.25 * 25 * [25-(14/12)2] / (8*1000) = 401.613 ft-k Note: Height of drop panel >= ¼ of slab thickness Width of drop panel extension on each side >=1/6 of span length measured center-to-center of supports f for each beam is considered the smallest value 0.8 19 Shear check for flat slab with drop panel Figure 2.6: Shear check for flat slab with drop panel There are 2 critical sections for slab with drop panel (dash line) h = 8” hd ≥ h/4 8”/4 = 2” Therefore, the thickness of drop panel = 8” + 2” = 10” ; hd = Assume bar #5 to be used for reinforcement. Determine d1 d1 = 10” – – 0.625” = 8.625” Determine d2 by using dx = 8”-3/4-(0.625”/2) = 6.9375” dy = 6.9375” – 0.625” = 6.3125” d2 = (6.9375”+6.3125”)/2 = L/6 = 25’/6 = 6.625” 4.167’ Consequently, use 4.2’ for a length of drop panel from the center of the column. 20 Check shear at the edge of drop panel b0 Vu ØVc = 2[(4.2’*12”) + (6.625”)] + 2[(4.2’*12”) + (6.625”)] = 228.1” = [25’ * 25’ – {4.2’+ (6.625”/12”)} 2] * (224/1000) = 134.942 kips = (0.85) 4 = (0.85) 4 = 397.984 kips > 134.942 kips OK b0 d * 228.1” * 6.625” Check punching shear at the column Since the drop panel is thicker than the thickness of flat slab, the adjustment must be implemented.Therefore, The new U for the section over the drop panel Upanel = b0 Vu 224 psf + 1.5 * 150 psf * [(10”-8”)/12] = 261.5 psf = 2(14”+8.625”) + 2(14”+8.625”) = 90.5” = [(25’*25’ – 4.2’*4.2)*224/1000’] + [4.2’*4.2’ – {(14”+8.625”)/12”}2]261.5/1000 Vc = 139.732 kips = (0.85) 4 = 205.571 kips > 139.732 kips OK * 90.5 * 8.625/1000 For a flat slab, the slab thickness to be used for design is 8”. Ud = 224 psf Static moment = 397.619 ft-k 21 22 23 24 25 26 27 28 2.3 Slabs with interior beams between columns In order direct design method to be applicable the following condition shall be satisfied (ACI 318 section 13.6.1.6) 0.2≤ where Step 1 : Slab thickness and beam size: If >1 for all beams all the shear is transferred to the columns by beams, making it unnecessary to check shear while selecting the slab thickness Assume all beams to have sizes of 14 in width and 20 in depth The calculated α for both the edge and interior beam respectively are 1.86 and 2.1 respectively and this satisfy the above condition no shear failure checking required for slabs Corresponding average α values for a corner panel and interior panel are then The slab thickness will be determined by the thickness of the interior panel But not less than Therefore the assumed h= 7 inches can be comfortably selected as the thickness of the slab with interior beams running between columns 29 Loading , based on h= depth of slab 7 in considered U= 1.2 (150*7/12+15) +1.6*(50) =203 Psf Design static bending moment, Mo The design static moments for edge strips and interior strips are Edge strip L2= 12.5+ (4/12) = 12.83 ft ln= 25 ft Interior strip l2= 25 ft ln= 25 ft Reinforcement Calculation Assume bar # 5 is used , the depths, d, in the orthogonal direction are dx= depth for bars spanning in x-direction dy = depth for bar spanning in y-direction For an assumed j=0.925, compute trial area As, at a section of maximum moment, in this case (first interior negative middle strip) with Mu=-64.43 ft-kips per 12. Ft length 30 =2.915 in2 Compute a and a/d and check ρ≤ 0.75 ρb For ρ= 0.75 ρb from a table a/d= 0.444, the value obtained above is much less than this hence the slab thickness is safe against bending. Maximum spacing of shrinkage reinforcement in slabs 18in Smax= i.e Smax=18 in 2h 31 32 33 34 3. Beam and Column Design 3.0 General Information The beam and column design is done as per the requirements of the ACI code and particular procedures has been adopted from the book “Reinforced Concrete: Mechanics and Design” by James G. Macgregor, second edition. The beams designed include the edge beams in all floor and the interior beams in the first floor. In designing the columns, however, the regularity of the building both in plan and elevation has been considered in selecting representative columns. The panel dimensions are all the same between columns. This condition of the building integrity has made it easy in selecting representative columns, in which only these representative columns are designed and duplicated every where in the building where the category falls into. Accordingly, each column of the building will fall in any one of the following three categories. Moreover, as the frames are braced by shear walls as indicated in plan, the frame is considered as braced against side sway. Category one: A corner column This column is found in corner of each of the building units separated by expansion joint. This column is subjected to a biaxial bending which is attributed to the bending actions coming from the frames in each direction but balanced in opposite directions. Category two: An edge column This column is found on the periphery of the building units and is subjected to a small amount of bending in one direction and a substantial amount of bending in the other direction (that accounts to the bending due to an interior frame that joins the edge column and which not balanced on the other side) Category three: An interior column Pertaining to the uniformity in panel dimensions of the panels surrounding an interior column, the unbalanced moments that are transferred to an interior column is 35 insignificant. Thus, this column will be designed for an axial loading and minimum moments that will take care of accidental eccentricities. 3.1 Edge Beam Design The Edge beams designed include those beams on axes namely: Axis (A1- A2-A3-A4A5), Axis (5E-5D-5C-5B-5A), Axis (1A-1B-1C-1D, Axis (B6-B7-B8-B9-B10), and Axis (6B-6C). The choice of axes for design covers all the edges on all the three floors and the design have been made separately, for each floor as the loading is different. Flat plate Edge beam Design The flat plate edge beams are subjected to the following loads Share of the Bending moments in the edge column strips of the slab analysis by direct design method Weight of the stem of the beam Weight of the 1ft high parapet wall Loads due to the glass wall claddings For easiness of analysis, the bending moments from the column strips has been alternatively considered by just analyzing the beam by subjecting to a load share of the slab weight and floor loading of each panel adjacent to the beam. The load share to each beam from a particular panel is as shown in figure 3.1 below. This approach of loading the beam results in a slightly magnified moment as compared to the moments computed using the direct design method of the ACI code. 36 Where w= 12.5 ft * Pu ( panel ) w = 12.5 ft * 226.25 lb / ft 2 * 1k 2.82k / ft lb Figure 3.1 Panel load share that goes to an Edge Beam The thickness of parapet wall (assuming made of concrete) has been decided based on a guideline obtained from (www.carryduff.designes.co.uk/ technical/limiting-height-ofchimney-and-parapet-walls.html). As per this guideline; For 1ft high parapet wall the thickness of wall t= 6 in Factored Dead load of parapet wall = 1.2*12in *6in * 150lb 1 ft 2 1k k * * 0.09 3 2 ft 144in 1000lb ft Factored Dead weight of the beam stem/web (on the assumption that the total depth of the beam is 16 in and its width is 12 in). For instance, the thickness of the flat plate is 9 in, which has been already included in the floor loading, the corresponding beam stem load will be 150lb 1 ft 2 1k k = 1.2*12in *7in * 3 * * 0.11 2 ft 144in 1000lb ft Similarly for the edge beams in other floor the factored beam stem loads will be o on the edge beams on the floor with flat slab ( thickness of slab = 8 in) = 0.11 k 8 k * 0.125 ft 7 ft o on the edge beams of the floor slab with beams ( thickness of slab = 7 in) = 0.11 k 9 k * 0.141 ft 7 ft 37 The Glass curtain wall is assumed to be made from a 10mm (3/8 in) thick insulating glass unit paneled into vertical mullions which are 5ft apart on center to center and a horizontal mullion fitted into the vertical mullions to divide the storey glazing into Vision area and the Spandrel area. The glass curtain wall is hanging from the floor edges beams with vertical mullions attached to the edge beams. Therefore, the weight of the glass curtain wall which consists of: the glass itself, vertical and horizontal mullion, capping, connection to fix it in to the floor edge beams will be transferred into the edge beams as concentrated loads. However the following approximation has been made to simplify the load calculations attributed to the difficulty we face in understanding the details of the connections and finding out the detailed sizes of the vertical and horizontal mullions plus the capping. Approximations made o The weights of the connections, horizontal and vertical mullions and capping are assumed to amount as 50% of the glass weight o The load transferred to the edge beams is taken as distributed allover the length rather than concentrated at the points of connections. The glass loading and its accessories of a given panel along the story height is carried towards to the top and bottom floor edge beams equally. A diagrammatic representation of the load transfer is as indicated below. Figure 3.2 Glazing load dispersion diagram Load due to glass curtain wall Weight of a 10mm (3/8 in) glass is 5psf (glass information bulletin) Weight of connections, mullions, capping = 0.5*5= 2.5 psf Total weight of glass curtain wall = 7.5 psf 38 Accordingly, the loads due to curtain wall that will go to the edges beams as uniformly distributed loads will be as shown below, which is also clearly indicated in Table 3.1 that shows the summary of loading on edge beams Floor level Flat plate Flat slab Floor with beams Grade beams Factored load to beams due to glazing 1.2( 7.5*16/2) =72lb/ft = 0.072k/ft 1.2(7.5*(16/2+16/2)= 144 lb/ft = 0.144 k/ft 1.2(7.5*(16/2+26/2)=189 lb/ft =0.189 k/ft 1.2*(7.5*26/2)=117 lb/ft =0.117 k/ft Table 3.1 Summary of loading on Edge Beams Floor level Due to parapet wall Udl- k/ft Flat plate 0.09 Flat slab 0 Floor with beams 0 Grade beams 0 Factored Design loads Due to self weight of beam stem/web Udl- k/ft 0.11 0.125 0.141 0.251 Due to glass curtain walls Udl – k/ft 0.072 0.144 0.189 0.117 Weight from slabs ( triangular) w (k/ft) 2.82 2.79 2.61 0 In soliciting out the design actions (bending moment and shear forces) for the edge beams a frame analysis using SAP 2000 is done to analyze the frame consisting of edge beams from top to bottom. Frame on axis (A1- A2-A3-A4-A5), one of the frame types analyzed, with full loading is as shown in figure 3.3 below. In addition the edge beams will be designed for torsion moments which are the negative exterior column strip moments of the column strips spanning into the edge beams from the slab analysis using the directed design method. The output of the frames analyzed for the beams has been hand picked. The outputs taken are the negative moments at the supports and the span moments plus the shear forces at each end of the beam. A sample of the outputs selected for the frame on axis (A1-A2-A3A4- A5) is shown in Table 3.2. 39 Figure 3.3 Loaded Frame on Axis ((A1-A2-A3-A4- A5) Table 3.2 Design Moments from SAP analysis output for frame on Axis ((A1-A2-A3-A4- A5) Moments (kips-ft) Beams @level Flat plate Flat Slab Slab w/beams Ground A1 support 66.75 90.53 74.42 A1-A2 span 76.01 65.43 68.6 A2 support 118.74 110.00 111.71 A2-A3 span 59.64 60.2 57.58 A3 support 103.49 105.26 100.73 A3-A4 span 59.64 60.2 57.88 A4 support 118.74 110 111.71 A4-A5 span 76.01 65.43 68.6 A5 support 66.75 90.53 74.42 18.21 9.77 19.5 9.45 19.29 9.45 19.5 9.77 18.21 40 Reinforcement calculations Checking assumed depth of beam for moment and shear capacity. Maximum moment every where in the beams is Mu = 118.79 kips-ft i.e. at the Flat plate edges beam at support A2 Assuming no compression reinforcement, the minimum depth required is given by Mu knbd 2 12000 d 1200M u ; b(in) M u (k ft ) kn b Assume the values of the steel ratio as follow 0.5b ; b 0.0377 for f c' 6000 psi and f y 60000 psi 0.019 for 0.019 kn 911 j 0.888 d 12.76in The required over all depth of beam D for the width b= 12 in is then D= 12.76 in +1.5in (cover) +.375in ( dtirrup)+.5 ( half bar diameter# 8) = 15.135 in D= 16 in used is ok! Checking shear capacity Maximum shear in the beams is Vmax = 22. 18 kips. This shall not be greater than the maximum allowed shear Vu , which is calculated based on the concrete strength , steel strength and the depth of the cross-section Vu= (Vc+Vs) = 2 fc/ bwd 8 f c/ bwd 106.65 kips is greater than the maximum applied shear so depth is satisfactory and can proceed with design of reinforcements. Longitudinal Reinforcement Calculations a) Support/ Negative moments (compression on web) – section is rectangular As M u (k ft )*12000 ; f y jd d 16 2.5 13.5in Mu,max = 118.79 k-ft b= 12 in and assume j = 0.875 As= 2.24 in2 41 Corresponding a = 2.2 in Since compression is on the web the beam behaves as rectangular with b= bw= 12 in and its ductile failure can easily checked that ≤b by checking if a/d ≤ 0.75(ab/d) a/d = 0.163 ≤ 0.333 ok ( failure is ductile failure) Using the above value of a re-compute As, this will result in a slightly more reinforcement than required. Thus, As M u (k ft )*12000 0.018M u f y (d a / 2) This formula is used to calculate the reinforcements for all support moments. b) Span/ Positive moments Mu,max = 76.01 k-ft Assume that compression zone rectangular and like with in the depth of the slab for the section of the beam to be considered (that accounts part of the slab as an effective flange) shown below. Assuming j = 0.95 M (k ft ) *12000 As u 1.31in 2 f y jd Then a As f y 0.85* f c'b 0.815 in a< h , therefore the assumption is correct compression zone lies on the flange Since compression zone lies all in all on the flange and section of beam beam is rectangular with b= 19 in it can easily checked that ≤b by checking if a/d ≤ 0.75(ab/d) a/d = 0.06 ≤ 0.333 ok ( failure is ductile failure) Therefore, for the positive moment regions, As can be calculated from 42 As M u (k ft )*12000 0.017 M u f y (d a / 2) This formula is used to calculate the reinforcement in span of the edge beams. All the rest of the calculations are done in an excel sheet presented below Flat Plate Edge beams Longitudinal Reinforcement bw(in)= 12 Beam (bw=12 in; d=14.5in) Support Moment A1 A2 -66.18 59.8 2.1528 1.2939 0.54 0.54 1.1912 1.2939 -66.18 76.56 1.854 2.1528 1.01062 0 1.01062 0.54 0.54 0.54 2.1528 1.01062 1.854 1.01062 0.54 A5 -119.6 59.8 1.1912 Min. reinf A4 -103 76.56 Req'd reinf.(in2), span Reinf Provide A3 -119.6 Span Moment Req'd reinf.(in2), supp d(in)= 13.5 1.19124 1.293864 0.54 0.54 0.54 2.1528 1.293864 1.19124 Bar # used 7 7 8 7 8 7 8 7 7 area of bar 0.6 0.6 0.79 0.6 0.79 0.6 0.79 0.6 0.6 1.9854 2.1564 2.7250633 1.68437 2.346835 1.684367 2.725063 2.15644 1.9854 #bars req'd bars used 2#7 2#7+1#6 3#8 bw(in)= 12 Beam (bw=12 in; d=14.5in) Support Moment 1B -66.02 Reinf Provide -119.8 1.1884 Req'd reinf.(in2), span 2#8 +1#7 2#7+1#6 -102.8 2.1564 0.54 1.1884 1.2934 1D -113.06 60.2 1.2934 0.54 2#7 1C 76.53 Min. reinf 2#8 + 1 #6 d(in)= 13.5 1A Span Moment Req'd reinf.(in2), supp 2#7 61.22 1.8504 1.01738 0.54 0.54 2.1564 1.01738 2.03508 0 1.034618 0.54 0.54 0.54 1.8504 1.034618 2.03508 Bar # used 7 7 8 7 8 7 8 area of bar 0.6 0.6 0.79 0.6 0.79 0.6 0.79 #bars req'd bars used 1.9806 2.1556 2.7296203 1.69563 2.342278 1.724363 2.576051 2#7 2#7+1#6 3#8 2#7 2#8 + 1 #6 2#7 2#8 +1#7 43 2#7 bw(in)= 12 Beam (bw=12 in; d=14.5in) Support Moment 6B 6C 58.44 125.83 Span Moment Req'd reinf.(in2), supp 72 1.0636 Req'd reinf.(in2), span 2.290106 1.2456 Min. reinf 0.54 Reinf Provide d(in)= 13.5 0.54 0.54 1.0636 1.2456 2.290106 Bar # used 7 7 8 area of bar 0.6 0.6 0.79 #bars req'd 1.7727 2.076 2.8988684 # bars used 2#7 2#7 +1#6 3#8 Beam (bw=12 in; d=14.5in) 5E 5D Support Moment -64.08 -115.04 Span Moment Req'd reinf.(in2), supp 1.1534 2.07072 0 1.1534 1.2498 57.52 1.79496 0.98071 0 0 -66.42 76.56 2.13228 0 0.972088 0 2.07072 0.98071 5A -118.46 58.03 1.2498 Min. reinf 5B -99.72 73.95 Req'd reinf.(in2), span Reinf Provide 5C 0 1.293864 0 1.79496 0.972088 1.19556 0 0 0 2.13228 1.293864 1.19556 Bar # used 7 7 8 7 8 7 8 7 7 area of bar 0.6 0.6 0.79 0.6 0.79 0.6 0.79 0.6 0.6 1.9224 2.0829 2.6211646 1.63451 2.272101 1.620147 2.699089 2.15644 1.9926 #bars req'd bars used 2#7 2#7+1#6 2#8 +1#7 2#7 2#8 + 1 #6 2#7 2#8 +1#7 2#7+1#6 2#7 . Flat Slab Edge beams Longitudinal Reinforcement bw(in)= 12 Beam (bw=12 in; d=14.5in) Support Moment A1 Req'd reinf.(in2), supp Req'd reinf.(in2), span A2 -83.53 Span Moment d(in)= 13.5 A3 -99.74 59.39 1.5035 -96 55.2 1.79532 1.0037 A5 -99.74 -83.53 55.2 1.728 0.93288 A4 0 59.39 1.79532 0.93288 1.50354 1.003691 44 Min. reinf Reinf Provide 0.54 0.54 0.54 1.5035 1.0037 0.54 0.54 0.54 1.79532 0.93288 1.728 0.93288 0.54 0.54 0.54 1.79532 1.003691 1.50354 Bar # used 7 7 8 7 8 7 8 7 7 area of bar 0.6 0.6 0.79 0.6 0.79 0.6 0.79 0.6 0.6 2.5059 1.6728 2.272557 1.5548 2.272557 1.672818 2.5059 #bars req'd bars used 2#7+1#6 2#7 2#8 +1#6 bw(in)= 12 Beam (bw=12 in; d=14.5in) Support Moment -83.41 -99.9 59.37 1.7982 1.0034 0.54 2#7 2#8 +1#6 2 #7 1C 1D -94.84 -101.2 55.45 1.5014 Min. reinf 2#8+1#6 1B Req'd reinf.(in2), span Reinf Provide 2#7 1.70712 1.8216 0.93711 0 0.93119 0.54 0.54 0.54 0.54 1.7982 0.93711 1.70712 0.93119 1.8216 0.54 0.54 1.5014 1.0034 55.1 Bar # used 7 7 8 7 8 7 8 area of bar 0.6 0.6 0.79 0.6 0.79 0.6 0.79 #bars req'd bars used 2.5023 1.6723 2.2762025 1.56184 2.160911 1.551983 2.305823 2#7+1#6 2#7 2#8 +1#6 bw(in)= 12 Beam (bw=12 in; d=14.5in) Support Moment Reinf Provide 77.74 2#8 +1#6 59.82 1.4149 1.921192 1.0349 0.54 0.54 0.54 1.4149 1.0349 1.921192 7 7 8 area of bar 0.6 0.6 0.79 # bars used 2#7 105.56 Bar # used #bars req'd 2#8+1#6 6C Req'd reinf.(in2), span Min. reinf 2#7 d(in)= 13.5 6B Span Moment Req'd reinf.(in2), supp 2#7+1#6 d(in)= 13.5 1A Span Moment Req'd reinf.(in2), supp 1.5548 2.187342 2.3581 1.7248 2.4318886 2#7+1#6 2#7 2#8 +1#6 45 Edge beams on floor slab with interior beams Longitudinal Reinforcement bw(in)= 12 Beam (bw=12 in; d=14.5in) Support Moment A1 A2 -69.34 Span Moment Req'd reinf.(in2), supp A3 -104.5 0.54 0.54 1.2481 1.0955 64.82 1.6938 0.91784 0.54 -69.34 54.31 1.881 1.0955 A5 -104.5 54.31 1.2481 Min. reinf A4 -94.1 64.82 Req'd reinf.(in2), span Reinf Provide d(in)= 13.5 1.881 0 0.917839 0.54 0.54 1.881 0.91784 1.24812 1.095458 0.54 0.54 1.6938 0.917839 0.54 0.54 1.881 1.095458 1.24812 Bar # used 7 7 8 7 8 7 8 7 7 area of bar 0.6 0.6 0.79 0.6 0.79 0.6 0.79 0.6 0.6 2.0802 1.8258 2.3810127 1.52973 2.144051 1.529732 2.381013 1.825763 2.0802 #bars req'd bars used 2#7 2#7 2#8 +1#6 bw(in)= 12 Beam (bw=12 in; d=14.5in) 1B -69.4 Reinf Provide 1.881 1.0951 0.54 2 #7 -99.8 55.13 1.6812 0.92156 0.54 0.54 1.2492 1.0951 0.54 1.881 0.92156 1.7964 0 0.931697 0.54 0.54 0.54 1.6812 0.931697 1.7964 Bar # used 7 7 8 7 8 7 8 area of bar 0.6 0.6 0.79 0.6 0.79 0.6 0.79 #bars req'd bars used 2.082 1.8252 2.3810127 1.53593 2.128101 1.552828 2.273924 2#7+1#6 2#7 2#8 +1#6 bw(in)= 12 Beam (bw=12 in; d=14.5in) Support Moment 6B 2#7 2#8+1#6 2#7 2#8 +1#6 d(in)= 13.5 6C 64.97 Span Moment Req'd reinf.(in2), supp 2#7+1#6 1D 54.53 1.2492 Min. reinf 2#8 +1#6 -93.4 64.8 Req'd reinf.(in2), span 2#7 1C -104.5 Span Moment Req'd reinf.(in2), supp 2#8+1#6 d(in)= 13.5 1A Support Moment 2#7 111.56 63.92 1.1825 2.030392 46 Req'd reinf.(in2), span 1.1058 Min. reinf 0.54 Reinf Provide 0.54 0.54 1.1825 1.1058 2.030392 Bar # used 7 7 8 area of bar 0.6 0.6 0.79 #bars req'd 1.9708 # bars used 2#7 1.843 2.5701165 2#7 2#8 +1#7 Design for Shear and Torsion For the edge beams the analysis results showed that the shear forces at critical sections are almost the same for all the edge beams in a floor with a slight difference of only 2kips. Therefore all edge beams are designed for the highest shear forces value in the beams in each floor. The load and shear force diagram for the edge beam with the larger shear, which is found on the flat plate floor, is as depicted in figure 3.4. Figure 3.4 loading and shear force diagram for beam A1- A2 of the flat plate floor Design shear at d distance from face of support is Vd = 23.1 -.5*(.248*20.5/12+.27)*20.5/12 = 22.5 kips Design for shear Vn Vd 22.5 26.4kips 0.85 47 Check if stirrups are required as per ACI 11.5.5 Vc 2 fcbw d 25.1kips Vn 26.4kips is greater than Vc 2 12.54 Therefore stirrups are required Check selected stirrups for anchorage and maximum spacing Try No. 3 double leg stirrups with fy = 60000psi in which case Av= 0.22 in2 . Since the bar used for stirrups is less No. 6 ACI recommends that the stirrups be anchored by a 900 hook around a bar.As per ACI 11.4.5, the maximum spacing shall be the smaller of the following Smax 0.5d 6.75in d / 4 3.375 if Vn 6 f c' bw d 75.3 kips (not to beused ) f y Av ,min 60000*0.22 14.7 in 50*12 50bw Smax = 6.75 in Compute the required stirrup spacing to resist the design shear forces For vertical stirrups s Av f y d Vn Vc .22*60000*13.5 137in (26.4 25.1)*1000 use double leg # 3 bars at a spacing s=6.75 in all over the beam. As this is the maximum shear, the same spacing of stirrup is to be used all over the edge beams. Torsion Consideration at Edge Beams The torsional constant of the section is given by x x x 2 y max{(92 *19 7 2 *12), (162 *12 7 2 *9)} 2 y max{2127,3198} 2 y 3198in3 48 The torsion moment that acts on the edge beam is equal to the negative moment in the column strips of the floor system that span into the edge beams. That is the moments at the exterior supports of the flood system shown in the tables in the slab design section. For Flat Plate floor edge beams, the maximum exterior negative column strip moment is 114.89 k-ft per 12.5 ft strip Td =114.89/12.5 = 9.19 k-ft Check whether torsion reinforcement is required or not fc/ x2 y .85* 6000 *3198/12000 17.54k ft Td = 9.19 is less than to 17.54 k-ft , therefore no torsion reinforcement is required . Thus provide reinforcement for the edge beams as per the specification stated in the tables below for main reinforcement and provide #3 bar double-legged stirrup @ 6.75 in center-to-center 3.2 Interior beams Interior beams are only present at the second floor of the building. The loads to which these beams are subjected include o Self weight of the beam o Floor loads and floor weight In the analysis of direct design method, the moments from the slabs carried by an adjacent beam to a column strip of the slab has been calculated during slab analysis. Therefore the moment due to floor weight and floor loading are picked from the table of moments done for slab analysis. However, the beams shear forces and additional moment due to its unit weight need to be calculated in a different manner. For which two different frame analyses has been done for each axis of beams, one for additional moment calculation and the other for shear calculation(assumption all the shear is transferred to the column through shear force in beams). Figures 3.5 and 3.6 show the frame loadings for axis (axis 1B-2B-3B-4B-5B) for this purpose. 49 Figure 3.5 Loading diagram (axis 1B-2B-3B-4B-5B) for the purpose of calculating additional moments due to self weight of beam Figure 3.6 loading diagram (axis 1B-2B-3B-4B-5B) for the purpose of calculating shear in internal beams due to loads from slab However, the shear calculated using the diagram in figure 3.6 need to be adjusted by multiplying by 1l2 l1 if 1l2 l1 1.0 as per ACI 13.6. Therefore the total shear force used in design for the design of the beam will be the shear force obtained from figure 3.5 50 and the adjusted shear from figure 3.6 . For an interior beam with the beam the value of 1l2 l1 is calculated as follows 3 0.7165* 25 E b a 0.72 f cb f 1l2 l 1 25 Ecs l h b,ft h,ft a 1 0.583333 f L,slab 1.5 a/h b/h 1.333333 2.285714 1.714286 α 25 0.716501 The design moments and shear forces for the internal beams on axis 1B-2B-3B-4B-5B are as indicated in Table 3.3 and Table 3.4 respectively. Table 3.3 Design Moments for internal beams on axis 1B-2B-3B-4B-5B Interior beams From slab Due to own weight Md, Design Moment 1B support 34.75 4.95 1B-2B span 96.7 4.41 2B support 118.78 8.21 Moments (kips-ft) 2B-3B 3B 3B-4B span support span 59.39 110.3 59.39 3.52 7.14 3.52 4B support 118.78 8.21 4B-5B span 96.72 4.41 5B support 34.75 4.95 39.7 101.1 127 62.91 127 101.1 39.7 117.44 62.91 Table 3.4Design Shear forces for internal beams on axis 1B-2B-3B-4B-5B Interior beams From slab ( 1) Adjusted shear from slab (1)*0.72 Due to own weight Vd , design shear 1B support 31.2 22.46 2B support Left right 37.55 34.82 27 25.1 3B support left right 33.93 33.93 24.43 24.43 4B support left right 34.87 37.55 25.1 27 5B support 31.2 22.46 1.62 1.88 1.77 1.73 1.73 1.77 1.88 1.62 24.08 28.88 26.87 26.16 26.16 26.87 28.88 24.08 51 There will no be torsion load in internal beams as the panels on both sides of the beams are having the same loading and the same dimensions. Therefore the interior beams will be designed for shear and bending only. Reinforcement calculations Checking assumed depth of beam for moment and shear capacity. Maximum moment every where in the interior beams is Mu = 118.78 kips-ft i.e. at the support 2B Assuming no compression reinforcement, the minimum depth required is given by Mu knbd 2 12000 d 1200M u ; b(in) M u (k ft ) kn b Assume the values of the steel ratio as follow 0.5b ; b 0.0377 for f c' 6000 psi and f y 60000 psi 0.019 for 0.019 kn 911 j 0.888 d 12.76in The required over all depth of beam D for the width b= 12 inches is then D= 12.76 in +1.5in (cover) +.375in ( dtirrup)+.5 ( half bar diameter# 8) = 15.135 in D= 16 in used is ok! Checking shear capacity Maximum shear in the beams is Vmax = 28. 88 kips. This shall not be greater than the maximum allowed shear Vu , which is calculated based on the concrete strength , steel strength and the depth of the cross-section Vu= (Vc+Vs) = 2 fc/ bwd 8 f c/ bwd 106.65 kips is greater than the maximum applied shear so depth is satisfactory and can proceed with design of reinforcements. 52 Longitudinal Reinforcement Calculations a) Support/ Negative moments (compression on web) – section is rectangular As M u (k ft )*12000 ; f y jd d 16 2.5 13.5in Mu,max = 118.789 k-ft b= 12 in and assume j = 0.875 As= 2.24 in2 Corresponding a = 2.2 in Since compression is on the web and beam section is rectangular with b= bw= 12 inches and it can easily checked that ≤b by checking if a/d ≤ 0.75(ab/d) a/d = 0.163 ≤ 0.333 ok ( failure is ductile failure) Re-compute As As M u (k ft )*12000 0.018M u f y (d a / 2) This formula is used to calculate the reinforcements for all support moments. b) Span/ Positive moments Mu,max = 101.1 k-ft Assume that compression zone rectangular and lies within the depth of the slab for the section of the beam to be considered (that accounts part of the slab as an effective flange) shown below. Assuming j = 0.95 M (k ft ) *12000 As u 1.743 in 2 f y jd Then a As f y 0.686 in 0.85* f c'b a< h , therefore the assumption is correct compression zone lies on the flange Since compression zone lies all in all on the flange and beamsecion is rectangular with b= 19 inches and it can easily checked that ≤b by checking if a/d ≤ 0.75(ab/d) a/d = 0.051 ≤ 0.333 ok ( failure is ductile) 53 Therefore, for the positive moment regions, As can be calculated from As M u (k ft )*12000 0.0169M u f y (d a / 2) This formula is used to calculate the reinforcement in the span of the interior beams. All the rest of the calculations are done in an excel sheet presented below Interior Beams Beam (bw=12 in; d=14.5in) Support Moment Span Moment Req'd reinf.(in2), supp Req'd reinf.(in2), span Min. reinf Reinf Provide Bar # used area of bar #bars req'd bars used Beam (bw=12 in; d=14.5in) Support Moment Span Moment Req'd reinf.(in2), supp Req'd reinf.(in2), span Min. reinf Reinf Provide Bar # used area of bar #bars req'd bars used Beam (bw=12 in; d=14.5in) Support Moment Span Moment Req'd reinf.(in2), supp Req'd reinf.(in2), span Min. reinf Reinf Provide Bar # used area of bar #bars req'd bars used bw(in)= 12 d(in)= 13.5 B1 B2 B3 -41.75 -130.5 -120.5 103.03 64.3 0.752 2.349 2.169 1.7412 1.08667 0 0.54 0.54 0.54 0.54 0.54 0.752 1.7412 2.349 1.08667 2.169 7 7 8 7 8 0.6 0.6 0.79 0.6 0.79 1.253 2.902 2.9734 1.81112 2.7456 2#6 3#7 bw(in)= 12 8B -41.75 3#8 2#7 d(in)= 13.5 8C -130.5 96.72 0.752 1.6346 1.08667 0.54 0.54 0.54 0.54 0.752 1.6346 2.349 1.08667 7 7 8 7 0.6 0.6 0.79 0.6 1.253 2.7243 2.9734 1.81112 2#6 2#7 +1#6 3#8 2#7 64.3 8D -120.5 8E -120.5 0.54 2.174 7 0.6 3.624 3#8 2#7 3#8 2#7 3#7 64.3 3#8 2#6 8F -131 64.3 2.169 8G -42 96.75 2.349 0.75 1.09 1.0867 1.6351 0.54 0.54 0.54 0.54 0.54 0.54 1.09 2.169 1.0867 2.349 1.6351 0.75 7 8 7 8 7 7 0.6 0.79 0.6 0.79 0.6 0.6 1.81 2.74557 1.8111 2.973 2.7251 1.25 2#8+1#7 2#7 d(in)= 13.5 D3 D4 -120.8 -120.8 64.12 64.12 2.1744 2.1744 1.0836 1.08363 0 0.54 0.54 0.54 0.54 1.0836 2.1744 1.08363 2.1744 7 8 7 8 0.6 0.79 0.6 0.79 1.806 2.7524 1.80605 2.7524 0.752 1.09 1.7412 0.54 0.54 0.54 0.54 1.09 2.349 1.7412 0.752 7 8 7 7 0.6 0.79 0.6 0.6 1.81 2.97342 2.902 1.253 bw(in)= 12 D2 -120.8 2.174 103.03 3#8 2.169 0 0.54 2.169 8 0.79 2.7456 B5 -41.8 2.349 2#8+1#7 2#7 64.3 2.349 B4 -130.5 3#8 2#7 +1#6 3#8 2#7 +1#6 2#6 D5 -120.8 64.1 2.1744 1.08 0.54 0.54 1.08 2.1744 7 8 0.6 0.79 1.81 2.75241 2#7 3#8 54 Beam (bw=12 in; d=14.5in) Support Moment Span Moment Req'd reinf.(in2), supp Req'd reinf.(in2), span Min. reinf Reinf Provide Bar # used area of bar #bars req'd bars used Beam (bw=12 in; d=14.5in) Support Moment Span Moment Req'd reinf.(in2), supp Req'd reinf.(in2), span Min. reinf Reinf Provide Bar # used area of bar #bars req'd bars used Beam (bw=12 in; d=14.5in) Support Moment Span Moment Req'd reinf.(in2), supp Req'd reinf.(in2), span Min. reinf Reinf Provide Bar # used area of bar #bars req'd bars used bw(in)= 12 C1 -41.75 d(in)= 13.5 C2 -130.5 103.3 0.752 C3 -120.5 64.3 2.349 1.7458 1.08667 0.54 0.54 0.54 0.54 0.752 1.7458 2.349 1.08667 7 7 8 7 0.6 0.6 0.79 0.6 1.253 2.9096 2.9734 1.81112 2#6 3#7 3#8 bw(in)= 12 D7 -135.1 2#7 64.3 2.169 2.169 1.09 1.0867 0.54 0.54 0.54 0.54 1.09 2.169 1.0867 2.169 7 8 7 7 0.6 0.79 0.6 0.6 1.81 2.74557 1.8111 3.615 2#8+1#7 2#7 2#8+1#7 D9 -135.1 55 2.4318 0.9295 0.9295 0.54 0.54 0.54 0.54 2.432 0.9295 2.4318 0.9295 7 7 8 7 0.6 0.6 0.79 0.6 4.053 1.5492 3.0782 1.54917 3#7 +1#8 2#7 C5 -121 64.3 2.169 0 0.54 2.169 8 0.79 2.7456 2#8+1#7 2#7 d(in)= 13.5 D8 -135.1 55 2.432 C4 -120.5 3#7 +1#8 2#7 2.4318 0 0.54 2.4318 8 0.79 3.0782 3#7 +1#8 bw(in)= 12 d(in)= 13.5 7B 7C -7 -198.8 111.25 0.126 3.5784 1.8801 0.54 0.54 0.54 0.54 1.8801 3.5784 7 7 8 0.6 0.6 0.79 0.9 3.1335 4.5296 2#6 2#8 +1#6 4#8 +1#6 Design for Shear For the interior beams, the analysis results showed that the shear forces at critical sections are almost the same for all the interior beams in the floor with a slight difference of only 2kips. Therefore all interior beams in the floor are designed for the highest shear force 55 values of 28.88 kips (shear at 2B to the left) at all interior supports and 24.1 kps (shear at 1B) at exterior support. Vd = is taken to be the maximum shear at support as it not too large compared to shear at d-distance as seen in the design shear force calculation for edge beams = 28.88 kips Design for shear Vn Vd 28.88 33.97kips 0.85 Check if stirrups are required as per ACI 11.5.5 Vc 2 fc/ bwd 2* 6000 *12*13.5/1000 25.1kips Vn =33.97 kps is greater than Vc/2 = 12.55 kips, therefore stirrups are required. Check selected stirrups for anchorage and maximum spacing Try No. 3 double leg stirrups with fy = 60000psi in which case Av= 0.22 in2 . Since the bar used for stirrups is less No. 6 ACI recommends that the stirrups be anchored by a 900 hook around a bar. As per ACI 11.4.5, the maximum spacing shall be the smaller of the following Smax 0.5d 6.75in d / 4 3.375 if Vn 6 f c' bw d 75.3 kips (not to beused ) f y Av ,min 60000*0.22 14.7 in 50*12 50bw Smax = 6.75 in Compute the required stirrup spacing to resist the design shear forces For vertical stirrups s Av f y d Vn Vc .22*60000*13.5 20in (33.97 25.1)*1000 Use double leg # 3 bars at a spacing s=6.75 in all over the beam as governed by the maximum stirrup spaced for a given depth d. As this is the maximum shear, the same spacing of stirrup is to be used all over the interior beams. 56 3.5 Beam Reinforcement Detailing/ Drawings 57 FLAT PLATE EDGE BEAMS FLAT SLAB EDGE BEAMS 58 59 60 EDGE BEAMS ON SLAB WITH INTERIOR BEAMS INTERIOR BEAMS 61 INTERIOR BEAMS 62 63 64 Notes: 1. Cover to reinforcements 1.5 inches 2. Concrete 6000 psi and steel 60000psi are used 3. all top reinforcements labeled 2#4 are hanging bars 65 3.6 Corner Column (A1) Column dimensions: 14” x 14” Table 3.5 shows corner column loads from frame analysis (frame loading) Table 3.5 Corner column loading from frame analysis Column level Third story Second story First story Foundation column Axial load P ( kips) Moment, ft) Bottom 66.75 49.75 My (k- 37.82 77.9 Moment, Mx ( k-ft) bottom top 66.75 -49.28 49.75 -41.26 115.82 124.92 24.26 4.88 24.26 4.88 -13.33 2.13 -13.33 2.13 top -49.28 -41.26 Consider the third story column Moment M 2b 66.75 k ft and M1b 49.28 k ft . These are the same for both directions. Axial force Pu = 37.82 kips + self weight of columns 14 in*14in*16ft* 150 lb/ft 3 = 37.82 + (12 in/ ft) 2 *1000lb / k 37.82 3.27 41.1 kips Check for Slenderness ACI 10.10 considers a braced (non-sway) Column is short if klu M 34 12( 1b ) 40 r M 2b 16in 14.6 ft 12in / ft r 0.3* column dim ension 0.3*14in 4.2in lu 16 depth of beam 16 ft a) Column attachments 66 b) Top and bottom beam sections Figure 3.7 Corner column attachment and section of beams attached to it These sections are used in determining the slenderness of the column as per ACI 10.10 Ic Ic 14*143 in 4 1 ft 14*143 in 4 1 ft 3 16.67 in 2* 33.34in3 l 12*16 ft 12 in l 12*16 ft 12 in c top c bot Ib 163 *12in 4 93 *13in 4 13*9**3.52 in 4 1 ft 21.06in3 25 ft 12in lb top Ib 163 *12in 4 83 *13in 4 13* 8**42 in 4 1 ft 21.05in3 l 25 ft 12 in b bot t I I c b / lc top / lb top I c / lc bot 33.74in3 1.602 16.67in3 0.791 b 21.06in3 Ib / lb 21.05in3 bot 0.7 0.05(t b ) 0.82 1.0 k k 0.82 0.85 0.05min 0.88 1.0 klu 0.82*14.67 *12in M 34.3 and 34 12( 1b ) 42.86 40 r 4.2in M 2b klu 34.3 40 r 67 Therefore, column is not slender and treated as short column. Check for minimum moment requirements For braced columns emin= (0.6+0.03h)= 0.6+0.03*14= 1.02 in Pu*emin= 41.1*1.02/12= 3.49 k-ft Actual moments are greater than this minimum moment and hence the column is designed for actual moments. Compute magnified moments Magnified moment Mc, is given by M c b M 2b where b Cm 1 ( Pu / Pc ) 0.75; Cm 0.6 0.4 M 1b M 0.304 2b Pc EI 2 klu 2 ; EI 0.4 Ec I g 1 dns (design stage) ; Ec 57000 f c' 4.41*106 psi I g 144 /12 3201in 4 dns factored axial dead load 0.7 appx. factored servive axial load 2 4.41*106 *3201lb.in 2 1kips 3303kips (.82*16*12in) *(1 0.7) 1000lb Cm 0.304 b 0.309 1 b 1 1 ( Pu / Pc ) 1 (41.1/(0.75*3303)) Pc 2 * Therefore no magnification of moments is required due to curvature. And the design moment will be Mc = M2b = 66.75 k-ft in both directions The reinforcement required for the factored design actions of Pu=41.1 kips and Mx=My= 66.75 k-ft is 8 # 8 bars. The Design for reinforcement is made using STAAD etc of STAAD Pro using the option of ACI Code. A similar procedure is followed for the columns in other stories and the results are as indicated in table 3.6 68 Table 3.6 Design Loads Summary and Reinforcement provide for a Typical Corner Column Column@ level Column type Design actions P (kips) Mx(k-ft) Second st. short 84.44 first slender foundation short Magnified actions Reinforcement My(k-ft) Mx(k-ft) My(k-ft) provided 49.75 49.75 49.75 49.75 4#8 bars 127.67 24.26 24.26 24.26 24.26 4#8 bars 141.39 4.88 4.88 4.88 4.88 4#8 bars Tie design As lateral forces taken by the shear wall and hence the shear forces in column are insignificant. For this reason no shear is considered in the design of the columns and the resulting tie requirement from the design software is # 3 bars ties spaced 14 inches on center to center. 3.5 Edge Column (B1) Column dimensions: 14” x 14” The loading to each column of the edge column includes the loadings from the edge frame that runs from the top of the building down to the foundation, analyzed using SAP 2000 and from the adjacent slabs through shear and moment transfer. Consider the edge located at B1 of the top storey, the tributary area for shear and strip for moment transfer as indicated in figures 3.8 (a) and 3.8(b) The column loadings in the y- direction can be taken from the frame analysis done earlier for the purpose of the design of edge beams. However, the column loading (moment and shear) in the x- directions has to be obtained from the above two diagrams as per the ACI code of shear and moment transfer to columns from slabs. The moment in the x-direction will be the moment at the exterior support of column strip of the strip shown in figure 3.7(b). And the shear will be approximately the total flood load in the tributary area shown in figure 3.7(a). As this also includes the floor load that has been already considered in the frame loads of the edge frame only half of the load over the area shall be considered and added to the axial load obtained from the frame analysis. 69 a) Tributary area for shear transfer b) strip for moment transfer Figure 3.8 Load transfer to an edge column The column loadings in the y- direction can be taken from the frame analysis done earlier for the purpose of the design of edge beams. However, the column loading (moment and shear) in the x- directions has to be obtained from the above two diagrams as per the ACI code of shear and moment transfer to columns from slabs. The moment in the x-direction will be the moment at the exterior support of column strip of the strip shown in figure 3.8(b). And the shear will be approximately the total flood load in the tributary area shown in figure 3.8(a). As this also includes the floor load that has been already considered in the frame loads of the edge frame only half of the load over the area shall be considered and added to the axial load obtained from the frame analysis. Load from frame loading ( Y direction) P = 44.42 kips M 1by= -3.74kips M2by = 7.41 kips Load transfer from slab P = 0.5* 226.25 psf * 12.5ft*25ft * 1k/1000lb= 35.35 kips M1bx = 114.89 k-ft (taken from flat plate) M2bx = -0.5 *113.75 =56.87 k-ft (this is the moment transferred to the bottom of the third story column B1 from the flat slab and it is shared between this column and the column 70 below it. The share of the moments is based on their corresponding stiffness which in this case is the same and each will take half of the moment. Total column loading P= 44.42+33.35+ self weight of column= 77.77+3.27=81.04 kips M 1by= -3.74kips M2by = 7.41 kips M1bx = 114.89 k-ft M2bx = -56.87 k-ft A similar procedure is followed for the columns in the other stories and the edge column (B1) loadings are as indicated in table 3.7. Table 3.7 acting design loads before magnification for edge column Column level Axial load P ( kips) 81.04 163.65 Moment, My ( k-ft) bottom top -3.74 7.41 -1.96 4.12 Moment, Mx (kft) (from slab) Bottom top -56.87 114.89 -28.48 56.87 third story, Second story First story Foundation column 244.14 255 -1.02 -0.15 -28.48 0 2.35 0.48 28.48 0 For details of the calculation on magnification and slenderness of the columns, consider the third story column B1. Figure 3.9 shows its attachment / framing to the building elements. Figure 3.9 Edge Column attachments to slabs/ beams in both directions 71 Check for Slenderness ACI 10.10 considers a braced (non-sway) Column is short if 16in 14.6 ft 12in / ft 9in klu M 1b l 16 depth of slab 16 ft 15.25 ft 34 12( ) 40 ux 12in / ft r M 2b r 0.3* column dim ension 0.3*14in 4.2in luy 16 depth of beam 16 ft Cross sections of beams are the same sections used in the checking of slenderness for the corner column of the third story. The slab x-section to be used for the x-direction are shown below Y-direction Ic 3 16.67in lc top Ic 3 2*16.67 33.34in lc bot Ib 3 3 2*21.06in 42.12in lb top Ib 3 3 2*21.05in 42.1in lb bot t I I c b / lc top / lb top 16.67in3 0.396 42.12in3 X-direction Ic 3 16.67in l c top Ic 3 3 2*16.67in 33.34in lc bot Ib 93 in3 *150in /12 1 ft 30.375in 4 25 ft 12in lb top Ib 83 in3 *150in 4 /12 1 ft 21.33in3 l 25 ft 12 in b bot t I I c b / lc top / lb top 16.67in3 0.55 30.375in3 72 Y-direction b I I c b / lc bot / lb bot X-direction 33.74in3 0.801 42.10in3 0.7 0.05(t b ) 0.76 1.0 k 0.85 0.05 min 0.87 1.0 k 0.76 kluy 0.76*14.67 *12in 31.8 r 4.2in M and 34 12( 1b ) 40.06 40 M 2b kluy r b c b / lc bot / lb bot 33.74in3 1.58 21.33in3 0.7 0.05(t b ) 0.81 1.0 k 0.85 0.05min 0.88 1.0 k 0.81 klux 0.81*15.25*12in 35.29 r 4.2in M and 34 12( 1b ) 39.94 40 M 2b 31.3 40 I I klux 35.29 39.94 r Therefore, column is not slender in both directions. Check for minimum moment requirements For braced columns emin= (0.6+0.03h)= 0.6+0.03*14= 1.02 in Pu*emin= 81.04*1.02/12= 7.14 k-ft Actual max end moments are greater than this minimum moment and hence the column is designed for actual moments. Compute magnified moments Magnified moment Mc, is given by M c b M 2b where b Y-direction X-direction Cmy 0.6 0.4 by M 1by M 2by 0.4 Cmy 0.4 by 1 (0.75*3303) Cmy 0.6 0.4 bx 1 ( Pu / Pc ) 1 81.04 Cm 1 ( Pu / Pc ) 0.41 M 1by M 2by 0.402 Cmy 1 ( Pu / Pc ) 0.402 0.41 1 81.04 (0.75*3303) bx 1 73 Therefore no magnification of moments is required due to curvature. And the design moments will be Mcy = M2by = 7.43 k-ft and Mcx=M2bx= 114.89 k-ft The reinforcement required for the factored design actions of Pu=81.04 kips and Mx=7.43 k- ft, My= 114.89 k-ft is 6 # 8 bars. The Design for reinforcement is made using STAAD etc of STAAD Pro using the option of ACI Code. A similar procedure is followed for the columns in other stories and the results are as summarized in table 3.8 Table 3.8 Design Loads Summary and Reinforcement provided for a Typical Edge Column Column@ level Column type Analysis actions P (kips) Mx(k-ft) Second st. short 163.65 first slender foundation short Magnified actions Reinforcement My(k-ft) Mx(k-ft) My(k-ft) provided 4.12 56.87 13.9 56.87 4#8 bars 244.14 2.35 28.48 28.66 28.66 4#8 bars 255 .48 0 21.65 21.65 4#8 bars Tie design As lateral forces taken by the shear wall and hence the shear forces in column are insignificant. For this reason no shear is considered in the design of the columns and the resulting tie requirement from the design software is # 3 bars ties spaced 14 inches on center to center. 3.6 Interior Column Column dimensions: 14” x 14” The regularity of the building units and the equity of the panel dimension both in the xand y- directions will result in an almost zero unbalanced moment to be transferred to the columns. Therefore, the interior columns will be designed for an axial force (which is determined based on the tributary area of the floor that is carried by a specific internal column plus the self weight of the column and internal beams, if present) plus the 74 minimum moment that account for minimum accidental eccentricity. The summary of the axial loads that act on each column in respective story is as shown in table 3.9 Table 3.9 Acting Column Axial loads for an interior column Column Load from level top story kips Third 00 story second 144.67 First 287.93 ground 425.2 Load from floor- kips 226.25*25*25/1000=141.4 224*25*25/1000=140 209*25*25/1000=130.63 0 Load due to beam if any (kips) 0 Self weight of column -kips 3.27 Total axial force kips 144.67 0 1.33 1.33 3.27 5.31 1.02 287.93 425.2 427.55 Consider the column at the bottom story. Its attachment to the building elements is as indicated in figure 3.9 in both directions. Figure 3.10 Interior Column attachments to slabs/ beams Check for Slenderness ACI 10.10 considers a braced (non-sway) Column is short if klu M 34 12( 1b ) 40 r M 2b 16in =24.67ft 12in/ft r=0.3*column dimension=0.3*14in=4.2in lu 26-depth of beam=26ft- 75 Ic Ic 14*143 in 4 1 ft 14*143 in 4 1 ft 14*143 in 4 1 ft 3 16.67 26.93 in 63.61in3 l 12* 26 ft 12 in l 12* 26 ft 12 in 12*5 ft 12 in c top c bot Ib 163 *12in 4 /12 73 *18in 4 /12 18*7 **4.52 in 4 1 ft 47.75in3 2* 25 ft 12in lb top Ib 163 *12in 4 /12 1 ft 2* 27.3in3 l 25 ft 12 in b bot t I I c b / lc top / lb top I c / lc bot 63.61in3 2.33 26.93in3 0.564 b 47.75in3 Ib / lb 27.3in3 bot 0.7 0.05(t b ) 0.845 1.0 k k 0.845 0.85 0.05min 0.88 1.0 klu 0.845* 24.67 *12in M 59.56 and 34 12( 1b ) 22 40 r 4.2in M 2b klu 59.26 22 r Therefore, column is slender in both directions. Minimum moment requirements For braced columns emin= (0.6+0.03h)= 0.6+0.03*14= 1.02 in Pu*emin= 425.2*1.02/12= 36.14 k-ft These are the moments to be considered for design as governed by minimum eccentricity. Compute magnified moments Magnified moment Mc, is given by M c b M 2b where b Cm 1 ( Pu / Pc ) and since klu 59.26 is less 100 the limit set by ACI 10.11 then the un-cracked gross section of r the column can be used to calculate EI for the computation of Pc. 76 M c b M 2b where b Cm 1 ( Pu / Pc ) 0.75; Cm 0.6 0.4 M 1b M 1 2b Pc EI 2 klu 2 ; EI 0.4 Ec I g 1 dns (design stage) ; Ec 57000 f c' 4.41*106 psi I g 144 /12 3201in 4 dns factored axial dead load 0.7 appx. factored servive axial load 2 4.41*106 *3201lb.in 2 1kips 1179kips (.845* 26*12in) *(1 0.7) 1000lb Cm 1 b 2.08 1 b 2.08 1 ( Pu / Pc ) 1 (425.2 /(0.75*1179)) Pc 2 * Therefore magnification of moments is required due to curvature. And the design moments will be Mc = M2by = M2bx=2.08* 36.14 = 75.17 k-ft The reinforcement required for the factored design actions of Pu=425.2k and Mx=My= 75.17 k- ft is 8 #8bars. The Design for reinforcement is made using STAAD etc of STAAD Pro using the option of ACI Code. A similar procedure is followed for the columns in other stories and the results are as tabulated in table 3.10. Table 3.10 Design Loads Summary and Reinforcement provided for a Typical Interior Column Column@ level Column type Design actions P (kips) Mx(k-ft) Third stor. short 144.67 Second st. short first slender foundation short Magnified actions Reinforcement My(k-ft) Mx(k-ft) My(k-ft) provided 0 0 13.1 13.1 4#8 bars 287.93 0 0 27.68 27.68 4#8 bars 425.2 0 0 75.17 75.17 8#8 427.5 0 0 44 44 8#8 bars 77 3.8 Column Reinforcement Detailing /Drawings Note: Cover to reinforcement 1.5 inches Depth of foundation column considered is 5 feet Concrete 6000psi and steel 60000psi are used Reinforcements of the foundation column run into the footing as dowels for anchorage purpose 78 4 Staircase Design 4.1 General Information Design of Staircase here it is adopted by the Cantilever Stairs Cantilever Stairs most commonly on fire escape stairs where vertical wall offers Protection in addition to its structural use. These may be adapted to many forms full flight, half flight or semi-spiral .Because the span of the cantilever is the same for each case the waist thickness is no different for full flight than for half flight . The Main reinforcement is placed in the top of the tread this beign the tension zone and it is tied back into the far face of the supporting wall for a full tension lap 4.2 Staircase Design Fig4.1 Building Plan View 79 Flight From First Floor to Second Floor Functional Planning Riser =7 inches (Refer Page 212 IBC) Tread =11 inches (Refer Page 212 IBC) No. Of Riser = Floor to Floor Height = 192/7 =28 Riser Riser = 192/28= 6.86 inches No. of Riser in each flight = 28/2 =14 nos No. of Tread in each flight =14-1 =13 nos Going = 13 x 11 =143 Inches Passage = ((24 x12) -Going )/2 = 145/2 = 72.5 inches As from page 213 IBC the width of Landing shall not be less than the width of Stairway they Serve that is 145 inches> 143 inches So Assumption is correct Waist Slab = 125mm (4.925 inches) Density of Concrete (ρ) = 150 Psf Wall Thickness =10 inches (From page 242 ACI Code) Steel Grade Fy = 60000 Psi Concrete Grade Fc= 5000 Psi Cosφ =6.86/12.96 Φ= 58.04 θ= 180-90-58.04= 31.96 d1/6.86 = Sin 58.04 d1 =5.82’ d2 = 4.925’ D=d1+d2 = 10.75’ 80 Fig4.2 Staircase Plan View Consider Span AB 81 Load Calculation Total Load =Live Load + Dead Load = (L.L+ Floor to Floor Finish + Self Weight of Waist Slab + Weight of Step) Live Load (Wl ) = 100 Psf (Refer page 286 IBC) Dead Load (Wd ) =( Floor finish+ Self weight of Waist Slab+ Wt. Of Step) Floor Finish= 23 Psf (Refer Page 247 ASCE) Self Weight of Waist Slab= (150 x 4.925/12 x Cos31.96) =72.56 lb/ft Weight of Step= (150 x 141 x 6.86 /2 x 144 ) = 503.78 lb/ft Wd = 23+72.56+503.78 = 600 lb/ft Factored Load ( Wu ) = 1.4Wd+1.7Wl = 1.4 x 600 + 1.7 x 100 = 1010 lb/ft For Cantilever = 0.8 Wu= 808 lb/ft Ma = Wl2 /2 = (808 x 11.752/ 2) = 55.78 Kips-Ft Tension is on the top of the beam Start a= 2 inch in then d=D-a = 10.75 -2 =8.75” Steel Area = Ast =Mu/ φ Fy (d-0.5a) = 55.78 x 12 / 0.9 x 60 x 7.75 = 1.6 inch2 a= Ast Fy/0.85 Fc’b = (1.6 x 60) /(0.85 x 5 x 12) = 1.9 Improved Steel Area = Ast= ( 56.768 x 12) / (0.9 x 60 x 7.8) = 1.617 inch2 Steel Reinforcing Ratio ρ =Ast/bd = (1.62) / (12 x 8.75) = 1/65 Minimum Steel Reinforcement ρmin = Max. = ρ > ρmin = ……………………….OK 82 ρmax = 0.6375 x 0.85 x = 0.6375 x 0.85 x x( ) x ) ρmax = ρmax > ρ …………………………OK Detailing of Reinforcement Ast = 0.6 inch2 # 7 Dia of bar =0.875 inch To find Spacing n x 0.6 =1.617 no. of spacing = 2.695 Spacing= = = 4.45” #7 @4.45” The Main Reinforcement is placed in the Top of the tread this being the Tension Zone and it is tied back into the far face of the supporting wall for a full tension lap Shrinkage & Temperature Reinforcement Cracking in grade 60 Slabs Area of Shrinkage = 0.0018 x 8.75 x 12 = 0.189 in2/ft By using ASTM Standards #3 Ast for one bar= 0.11 inch2 n x 0.11 = 0.189 Where, n= no.of Spacing n = 1.72 Spacing = = 7’ Therefore Shrinkage & Temperature bar can be placed at #3 @ 7” Development Length Development length required Ld= α = Location Factor =1 83 β = Coating Factor =1 λ = light weight agg. Concrete factor = 1 γ = Bar size factor = 1 = 42.64” Ld = Ld = + la la = Max.(12 db, d) db= Bar diameter = 8.75” d= Effective depth= 0.875” Mu=56.768 Kips-Ft la = Max.(12 0.875, 8.75) = Max.(10.5,8.75) =10.5” a= 1.9” Mn=1.62 = 758.16 Ld= Ld= + 10.5 = 113.194” 113.194” > 42.64” Consider Span CD 84 Load Calculation Total Load =Live Load + Dead Load = (L.L+ Floor to Floor Finish + Self Weight of Waist Slab + Weight of Step) Live Load ( Wl )= 100 Psf (Refer page 286 IBC) Dead Load ( Wd ) =( Floor finish+ Self weight of Waist Slab+ Wt. Of Step) Floor Finish= 23 Psf (Refer Page 247 ASCE) Self Weight of Waist Slab= (150 x 4.925/12 x Cos31.96) =72.56 lb/ft Wd = 23+72.56 = 95.56 lb/ft Factored Load ( Wu ) = 1.4Wd+1.7Wl = 1.4 x 95.56 + 1.7 x 100 = 303.786 lb/ft For Cantilever = 0.8 Wu= 243 lb/ft Ma = Wl2 /2 = (243 x 6.052/ 2) = 4.43 Kips-Ft Tension is on the top of the beam Start a= 2 inch in then d=D-a = 10.75 -2 =8.75” Steel Area = Ast =Mu/ φ Fy (d-0.5a) = 4.43 x 12 / 0.9 x 60 x 1.178 = 0.84 inch2 a= Ast Fy/0.85 Fc’b = (0.83 x 60) /(0.85 x 5 x 12) = 0.98” Improved Steel Area = Ast= ( 4.43 x 12) / (0.9 x 60 x 1,68) = 0.58 inch2 Steel Reinforcing Ratio ρ =Ast/bd = (0.58) / (12 x 2.178) = 1/44.86 Minimum Steel Reinforcement ρmin = Max. = ρ > ρmin = ……………………….OK ρmax = 0.6375 x 0.85 x x( ) 85 = 0.6375 x 0.85 x x ) ρmax = ρmax > ρ …………………………OK Detailing of Reinforcement Ast = 0.2 inch2 # 4 Dia of bar =0.5 inch To find Spacing n x 0.2 =0.52 no. of spacing = 2.6 Spacing= = = 4.62” #7 @4.62” The Main Reinforcement is placed in the Top this being the Tension Zone and it is tied back into the far face of the supporting wall for a full tension lap Shrinkage & Temperature Reinforcement Cracking in grade 60 Slabs Area of Shrinkage = 0.0018 x 2.178 x 12 = 0.047 in2/ft By using ASTM Standards #3 Ast for one bar= 0.11 inch2 n x 0.11 = 0.189 Where, n= no.of Spacing n = 1.72 Spacing = = 7’ Therefore Shrinkage & Temperature bar can be placed at #3 @ 7” Development Length Development length required Ld= α = Location Factor =1 β = Coating Factor =1 86 λ = light weight agg. Concrete factor = 1 γ = Bar size factor = 1 = 42.64” Ld = Ld = + la la = Max.(12 db, d) db= Bar diameter = 0.5” d= Effective depth= 2,178” Mn=53.92 Kips-Ft la = Max.(12 0.5, 2.178) = Max.(6,2.178) =6” a= 0.9” Mn=0.52 = 53.92 Ld= + 6 = 58.69” Ld= 58.96” > 42.64”…………………OK Flight from Ground Floor to First Floor Functional Planning Riser =7 inches (Refer Page 212 IBC) Tread =11 inches (Refer Page 212 IBC) No. Of Riser = Floor to Floor Height = 312/7 =45 Riser Riser = 312/45= 6.86 inches Let us Assume 3 Flight Flight No 1= 17 Riser No. of Riser in each flight = 28/2 =14 nos 87 No. of Tread in each flight =14-1 =13 nos Going = 13 x 11 =143 Inches Design of Staircase remains same for Staircase from Ground Floor to First Floor Table 4.1 Detailing of Reinforcement Description ASTM Standard Size Location Main Reinforcement Along AB Span #7@4.45” In Tread Tension Zone Along CD Span #4@4.62” In Mid landing Span Shrinkage & Temperature #3@7” In Tread & Waist Slab in Reinforcement 1 both direction Shrinkage Cracking and Temperature Reinforcement is provided to minimize the cracking and tie the structure together and achieve structural integrity 2 Tension is on top of tread so main reinforcement is provided 3 Development length is provided is equal to length of the bar required to develop the required stress in steel 88 89 90 91 92 5 Shear Wall Design 5.1 General Information Horizontal forces acting on reinforced concrete structure are resisted by different system. Frames are commonly used for low rise construction. Such frames may also rely on the contribution of infill walls and partitions of lateral load resistance, especially if wind is the only lateral force consideration. When large load must be resisted, such as earthquake, or very high wind loads, shear walls are often used. In such buildings, shear walls may be constructed between column lines or may be incorporated into stair wells, elevator shafts or utility shafts. We have incorporated shear walls near elevators and staircase. The foundation must be designed to resist he shear and moment at the base of the wall. The reinforcement at the base must be careful detailed so that the forces can be transferred between the wall and the foundation. Here we have provided minimum Ast to control cracking and also the Shear reinforcement in both the longitudinal & transverse direction and generally it is placed in both faces of the wall. The longitudinal (Vertical) bars in the wall serve also as flexural reinforcement. 5.2 Shear Wall Design for Staircase Wind Load Calculation With reference ASCE Wind load calculation Page 27 ASCE we can find chapter on wind load calculation Basic Wind Speed V is determined for Syracuse Region from page 37 ASCE were V= 40 m/s Ps= =Adjustment Factor for Building Height I= Importance Factor Ps30=Simplified design wind Pressure for exposure With reference fig 6.2 From page 43 ASCE λ= 1.22 Ps30 here from table we can find the value of 93 A =12.8 Psf B=-6.7 Psf C= 8.5 Psf D=-4 Psf For Ps30=12.8+8.5 =21.3 Psf Ps=1.22 x 1 x 21.3 =25.986 Psf Therefore considering Ps=26 Psf Fig 5.1 Shear Force & Bending Moment Due to Wind Load Design of Shear wall follows the same approach as that for beams. The provision for Shear wall design is contained in ACI 11.10 Special provision for wall. Design of Horizontal section for Shear in the plane of wall is based on Vu ≤ øVn …………….From Code ACI equation 11.1 Vn =Vc+Vs………… From Code ACI equation 11.2 94 Check Maximum Shear Strength Permitted φVn= φ 10√fc’x hw x d Where d=0.8 x lw =0.8 x 24 x 10 = 192 inch Where lw is the Length of the Wall φVn= 0.75 x 10 x √5000 x 12 x 192/1000 φVn=1221.88 Kips Calculate Shear Strength Provided by Vc Critical Section for Shear is Therefore = = 12 feet Vc= 3.3√fc’ hw d + Nu d/4 lw Where Nu is the factored Axial Tensile Force Slab Reaction coming on to the wall = 3.0375 Kips Where Nu=3037.5 + 10 1 Therefore, Nu= 4537.5 lb Nu=4.537 Kips Vc= Vc= 538.36 Kips Minimum Reinforcement of Wall Vertical Reinforcement = 0.0012 = 0.144 inch2 As per ASTM Standards Reinforcing Bars Nominal Diameter =0.375 inch Nominal Area =0.11 inch2 Ast=0.1728/0.11 =1.57 Spacing =12/1.57 = 7 inch Therefore provide #3 @ 7 inch Minimum Horizontal Steel Ast= 0.0020 x b x d 95 Ast=0.002 x 12 x (12-0.5-0.25) Ast= 0.27 inch2 Provide # 3 @ 10 inches Providing Shrinkage Cracking Steel The minimum length of a lap splice when fy= 60 ksi is Lap = 0.0005xdbxfy = 0.0005x0.375x60 = 11.25in < Min lap (12in) Provide lap = 12in Development length in compression (ACI Code, section 12.2) ld = 0.04Abfy/fc = 0.04x0.31x60000/(6000) =10in< 12in Provided ld=12 in (min development length) As each wall is governed by the Minimum Area of Reinforcement .Therefore for each wall reinforcement & detailing remains the same. 96 97 98 5.3 Shear Wall Design for Elevator 1. Design of machine room slab Loads acting on slab are: Passenger load Lift load = 2205 lb = 4500 lb As we are providing two passenger elevators, the total load per ft² over roof from lifts is = 2*(2205+4500)/25² = 13410 psf Roof live load = 100 psf Finish load = 15psf Self wt. of slab: Assume depth of slab ‘d’=10” Self wt. of slab = 150x1’x1’x(10/12)’ = 125 psf Factored load(Wu) = 1.4D.L+1.7L.L = 1.4(125+22+15)+1.7(100)= 400 lb = 0.4 k Analyze the slab as a unit strip (b=12) &designed it as a beam: Factored Moment Mu = Wu*l² 8 Mu = 0.4x25² = 28.8k-ft 8 Checking shear capacity Maximum shear in the beams is Vu= (5x1.4=7kips) This shall not be greater than the maximum allowed shear, which is calculated based on the concrete strength, steel strength and the depth of the cross section Vn= 0.9x10xx12x7.5 = 69.71 kips > 7 kips 1000 Unit strip is safe against shear & we can proceed furthur. Area of steel As = Mu fy(d-a/2) = 28.8x12 0.9x60x (7.5-2/2) = 0.984in2 99 a = As.fy = 0.984x60 = 1.157 0.85fc’.b 0.85x5x12 Improvised Steel area = Mu = 28.8x12 fy(d-a/2 0.9x60(7.5-1.157/2) = 0.924 in² Provide #7 @7” (As = 1.02 in²) in both directions Development length in compression (ACI Code, section 12.2) ld = 0.04Abfy/ = 0.04x0.0.875x60000/(6000) =23.3in Provided ld =24 in 2. Design of Shear wall (above roof level) Axial compression force due to slab = 3.125k Axial compression force due self wt. of wall = 150x10’x1’x1’ = 1500 lb Maximum shear strength permitted Vu Vn where Vn = Vc+Vs Vc=3.3sqrt(fc’)h.d+Nu.d 4Lw Vc = 3.3sqrt(6000)x10x0.8x12 + 4625x0.8x12 1000 4x12x1000 Vc = 24.54+ 3.7 Vc= 0.85x28.24 = 24k Vn = 10sqrt(6000)x10x(0.8x12) = 74.36k 1000 Vn = 0.85x74.36 = 63.20k Vu = 0.260x1.4 = 0.365k Since Vu<<ØVc therefore no reinforcement is required but as per ACI code, their should be some minimum reinforcement provided to wall. The minimum shear reinforcement is provided by ACI wall section 14.3.2 Mini. Horizontal steel: Ast = 0.0020.b.d’= 0.0020x12x[10-0.75(cover)-0.25(half dia of bar)] Ast = 0.216 in² 100 Provide #4@ 10” The minimum length of a lap splice when fy= 60 ksi is (ACI code section 12.15&12.16) Lap = 0.0005xdbxfy = 0.0005x0.5x60 = 115in Provide lap = 15in Mini vertical steel: Ast = 0.0012.b.d’ = 0.0012x12x (10-0.5-0.75) = 0.1296 in² Provide #3 @9 (Ast =0.1467 in²) The minimum length of a lap splice when fy= 60 ksi is Lap = 0.0005xdbxfy = 0.0005x0.375x60 = 11.25in < Min lap(12in) Provide lap = 12in 3. Design of Shear wall (@base level) Axial compression force due to slabs =(5 + 3.125=8.125k) Axial compression force due self wt. of wall = 150x68.41’x1’x1’ = 102615lb = 10.26 kip Reactions from slabs = 8 kip (due to all slabs) Maximum shear strength permitted Vu Vn where Vn = Vc+Vs Vc=3.3sqrt(fc’)h.d + Nu.d 4Lw Where, Nu= 8.125+10.26+8 = 26.385 kips Lw =12in d = 0.8Lw=0.8x12 in h = 10in Vc = 3.3sqrt (6000) x10x0.8x12 + 102615x0.8x12 1000 Vc = 24.53 +20.523 4x12x1000 Vc = 0.85x45.053 = 36.05k 101 Vn = 10sqrt(6000)x10x(0.8x12) = 74.36 kips 1000 Vn = 0.85x74.36 = 93.206kips Vu = 1.768x1.4 = 2.475 kips Since Vu<<ØVc therefore no reinforcement is required but as per ACI code the their should be some minimum reinforcement provided to wall. The minimum shear reinforcement is provided by ACI wall section 14.3.2 Mini. Horizontal steel: Ast = 0.0020.b.d’ = 0.0020x12x9 = 0.216 in2 Provide #4@ 10” The minimum length of a lap splice when fy= 60 ksi is Lap = 0.0005xdbxfy= 0.0005x0.5x60 = 115in Provide lap = 15in Development length in compression (ACI Code, section 12.2) ld = 0.04Abfy/fc = 0.04x0.20x60000/(6000) =16in Mini vertical steel: Ast = 0.0012.b.d’ = 0.0012x12x9.25= 0.1296 in² Provide #3 @9 (Ast =0.1467 in²) As the shear wall is all around the elevator only one part of shear wall was analyzed and designed and has resulted in a minimum steel at both the two extreme levels (i.e. one at the roof level and one at the foundation level). Therefore, the same minimum steel reinforcement is provided at all parts of shear wall as per ACI code. Also, the freight elevator shear wall is similar to the passenger elevator in terms of loading and shape, therefore we have provided the same reinforcement to it also as per ACI code. Specification of passenger and freight elevators installed Type Capacity(kg) Door Car dimension Passenger 1000 2S 5.9’x4.92’ elevator Freight 1000 3S 7.22’x7.4’ elevator Speed(m/s) 1.5 1.3 102 103 Detaailing of shear wall and slab connection 104 Slab1 – Machine room slab @roof level Slab2 – Machine room roof slab 105 106 Beams detail incorporated with shear wall footing (page 111,112) 107 Footing joint with shear wall 108 6. Foundations 6.1 General Information The foundation chosen for the building are of four types 1. Isolated footing under corner column 2. Isolated footing under edge columns 3. Isolated footing under interior columns 4. Common footing for columns which are at the junction of the different building units i.e. at points where we have the expansion joint. 6.2 Isolated footing under the corner column Load from superstructure P = 141.39 kips Mx=My=4.88 kips Figure 6.1 Footing load elements Assuming the following data Bearing capacity of soil = 6000psf = 6 ksf First floor loading is 100 psf = 0.1 psf Density of soil = 120 lb/ft3 weight of soil = 120*5= 600psf =0.6 ksf Thickness of footing =2* column size= 28in Net allowable soil pressure, qn qn 6.0 footpad soil floor floorload 6.0 [ 28 *0.15 5*0.12 0.5*0.15 0.1] 12 4.875 ksf Preliminary area of footing required, Aplim 109 Aplim 141.39kips 29 ft 2 , then try a square footing of 6ft by 6ft and 28 inch thick. 4.875ksf Acting net pressure calculation at corners of the footing qact P Mx y M yx (6 ft ) 4 but I x I y 108 ft 4 A Ix Iy 12 Where P= 141.39 + 1.2*(6ft*6ft)*(0.1+0.6+(28/12+6/12)*.15)=190 kips Mx=My=4.88 kips and A=36 ft2 At corner A qact 190 4.88*3 4.88*3 =5.55 ksf 36 108 108 At corner B qact 190 4.88*3 4.88*3 =5.28 ksf 36 108 108 At corner C qact 190 4.88*3 4.88*3 =5.01 ksf 36 108 108 At corner D qact 190 4.88*3 4.88*3 =5.28 ksf 36 108 108 Figure 6.2 Corner footing Bearing Pressure distribution Check the thickness for two way shear Assume # 9 bars are used for footing reinforcement dav 28" (3"cover) (bar diameter)=28"-3"-1.128"=23.87 in . The shear perimeter is shown in dashed lines. 110 Average pressure under the footing, qav 5.55 5.28 5.28 5.01 qav 5.28 ksf 4 Acting shear, Vu Vu 5.28*(36 ft 2 37.8 Figure 6.3 a) Corner two way shear Critical Section ft ) 137.7 kips 12 2 Length of critical shear perimeter bo = 4*37.8” =151.2 in As per ACI , the resistance shear is given by (2 4 ) f ' b d c o av c Vc min ( s d av b ) f c' bo d av o 4 f c' bo d av s = 40 for column at center of footing c =long side of column/short side of column =1 1421.59kips Vc min 1965.6kips Vc 947.7kips 947.7kips Vc is about seven times of Vu reduce the thickness assumed take h = 14 in d av 14" (3"cover) (bar diameter)=14"-3"-1.128"=9.87 in bo 4*(14 9.78) 95.12in 14 9.87 2 Vu 5.28*(36 ( ) ) 169kips 12 379kips Vc min 381kips Vc 248kips Vu 169kips 248kips Therefore take thickness D of footing as 14 inches. 111 Check one-way shear qav 5.55 5.28 5.415ksf 2 Vu 5.415*6*(3 (7 9.87) /12) 51.79kips Vc 2 f c' bd .85* 2* 6000 *6*9.87 /12 93.57kips Vu Footing is ok against one way shear Figure 6.3 b) Corner footing one way shear critical section Reinforcement Design qav 5.55 5.28 2 5.415ksf acting moment, M u 5.415*[6* (29 /12) 2 ] 2 94.87 k ft Assume that j= 0.9 Mu 94.87*12000 As = = =2.376 in 2 f y jd av .9*60000*(.9*9.87) Minimum As as per ACI 10.5 =0.0018bh =0.0018*72*14 1.81in 2 Minimum As doesn't govern. Figure 6.3 c) Corner footing critical section for bending Maximum spacing as per ACI 7.12 is 18 inches Try 6 # 6 bars @ 12 inches center to center As = 2.64 in2 112 Re-compute M n a As f y ' c 0.85* f b since 2.64*60000 0.431in 0.85*6000*72 0.75ab a 0.431 0.044 0.333 d av 9.78 d 0.9* 2.64*60000*(9.87 .431/ 2) 114.7k ft 12000 Therefore the reinforcement provided is enough and M n As f y (d av a ) 2 Mn Mu thus, provide 6#6 bars @ 12 in center to center both ways. 6.3 Isolated footing under the Edge column B1 Load from superstructure P = 255 kips Mx= 0 , My=21.65 kips Assuming the following data Bearing capacity of soil = 6000psf = 6 ksf First floor loading is 100 psf = 0.1 psf Density of soil = 120 lb/ft3 weight of soil = 120*5= 600psf =0.6 ksf Thickness of footing =2* column size= 28in Net allowable soil pressure, qn qn 6.0 footpad soil floor floorload 6.0 [ 28 *0.15 5*0.12 0.5*0.15 0.1] 12 4.875 ksf Preliminary area of footing required, Aplim Aplim 255kips 52.3 ft 2 , then try a square footing of 8 ft by 8 ft and 28 inch thick. 4.875ksf Acting net pressure calculation at corners of the footing 113 qact P Mx y M yx (8 ft ) 4 but I x I y 341.33 ft 4 A Ix Iy 12 Where P= 255 + 1.2*(8ft*8ft)*(0.1+0.6+(28/12+6/12)*.15)=341.5kips Mx= 0 My=21.65 kips and A=64 ft2 At corners A and B qact 341.5 21.56* 4 =5.59 ksf 64 341.33 At corner C and D qact 341.5 21.56* 4 =5.08 ksf 64 341.33 Check the thickness for two way shear Figure 6.4 Edge footing Bearing Pressure distribution Assume # 9 bars are used for footing reinforcement dav 28" (3"cover) (bar diameter)=28"-3"-1.128"=23.87 in . The shear perimeter is shown in dashed lines. Figure 6.5 a) Edge footing two way shear Critical Section Average pressure under the footing, qav 5.59 5.59 5.08 5.08 qav 5.34 ksf 4 Acting shear, Vu Vu 5.34*(64 ft 2 37.8 s = 40 for column at center of footing ft ) 288.77 kips 12 2 Length of critical shear perimeter bo = 4*37.8” =151.2 in As per ACI, the resistance shear is given by (2 4 ) f ' b d c o av c Vc min ( s d av b ) f c' bo d av o 4 f c' bo d av 114 c =long side of column/short side of column =1 1421.59kips Vc min 1965.6kips Vc 947.7kips 947.7kips Vc is about three times of Vu reduce the thickness assumed take h = 16 in d av 16" (3"cover) (bar diameter)=16"-3"-1.128"=11.87 in bo 4*(14 11.87) 103.48in 14 11.87 2 Vu 5.34*(64 ( ) ) 317kips 12 483.81kips Vc min 486.1kips Vc 322.55kips Vu 317kips 322.55kips Therefore take thickness D of footing as 16 inches. Check one-way shear qav 5.34ksf Vu 5.34*8*(4 (7 11.87) /12) 103.7 kips Vc 2 f c' bd .85* 2* 6000 *8*11.87 /12 150.04kips Vu Footing is ok against one way shear Figure 6.5 b) Edge footing one way shear critical section 115 Reinforcement Design qav 5.55 5.28 2 5.415ksf (41/12) 2 ] 2 249.35k ft acting moment, M u 5.34*[8* Assume that j= 0.9 Mu 249.35*12000 As = = =5.187 in 2 f y jd av .9*60000*(.9*11.87) Minimum As as per ACI 10.5 =0.0018bh =0.0018*96*16 2.76in 2 Minimum As doesn't govern. Figure 6.5 c) Edge footing critical section for bending Maximum spacing as per ACI 7.12 is 18 inches Try 8 # 8 bars @ 12 inches center to center As = 6.32 in2 Re-compute M n a As f y ' c 0.85* f b since 6.32*60000 0.775in 0.85*6000*96 0.75ab a 0.775 0.066 0.333 d av 11.78 d 0.9*6.32*60000*(11.87 .775 / 2) 326.5k ft 12000 Therefore the reinforcement provided is enough and M n As f y (d av a ) 2 Mn Mu thus, provide 8#8 bars @ 13.5 inches center to center both ways. 116 6.4 Isolated footing under an interior column Load from superstructure P = 427.5 kips Mx= 0 , My=0 Assuming the following data Bearing capacity of soil = 6000psf = 6 ksf First floor loading is 100 psf = 0.1 psf Density of soil = 120 lb/ft3 weight of soil = 120*5= 600psf =0.6 ksf Thickness of footing =2* column size= 28in Net allowable soil pressure, qn qn 6.0 footpad soil floor floorload 6.0 [ 28 *0.15 5*0.12 0.5*0.15 0.1] 12 4.875 ksf Preliminary area of footing required, Aplim Aplim 427.5kips 87.7 ft 2 , then try a square footing of 10.5 ft by 10.5 ft and 28 inch thick. 4.875ksf Acting net pressure calculation at corners of the footing qact P Mx y M yx (8 ft ) 4 but I x I y 341.33 ft 4 A Ix Iy 12 Where P= 427.5 + 1.2*(10.5ft*10.5ft)*(0.1+0.6+(28/12+6/12)*.15)=576.34 kips Mx= 0 My=0 and A=110.25 ft2 117 At corners A ,B,C and D qact 562.5 =5.63 ksf 100 Check the thickness for two way shear Figure 6.6 Interior footing Bearing Pressure distribution Assume # 9 bars are used for footing reinforcement dav 28" (3"cover) (bar diameter)=28"-3"-1.128"=23.87 in . The shear perimeter is shown in dashed lines. Figure 6.7 a) Interior footing two way shear Critical Section Average pressure under the footing, qav qav 5.63 ksf Acting shear, Vu Vu 5.63*(100 ft 2 37.8 ft ) 506.93 kips 12 2 Length of critical shear perimeter bo = 4*37.8” =151.2 in As per ACI , the resistance shear is given by (2 4 ) f ' b d c o av c Vc min ( s d av b ) f c' bo d av o s = 40 for column at center of footing 4 f c' bo d av c =long side of column/short side of column =1 1421.59kips Vc min 1965.6kips Vc 947.7kips 947.7kips 118 Vc is about two times of Vu reduce the thickness assumed take h = 21 in d av 21" (3"cover) (bar diameter)=21"-3"-1.128"=16.87 in bo 4*(14 15.87) 123.48in 14 16.87 2 Vu 5.63*(100 ( ) ) 525.74kips 12 822.92kips Vc min 749.52kips Vc 548.61kips Vu 525.74kips 548.61kips Therefore take thickness D of footing as 21 inches. Check one-way shear qav 5.63ksf Vu 5.63*10*(5 (7 16.87) /12) 169.5kips Vc 2 f c' bd .85* 2* 6000 *10*16.87 /12 271.2kips Vu Footing is ok against one way shear Figure 6.7 b) Interior footing one way shear critical section Reinforcement Design qav 5.63ksf (53 /12) 2 ] 2 549.12k ft acting moment, M u 5.63*[10* Assume that j= 0.9 Mu 549.12*12000 As = = =8.04 in 2 f y jd av .9*60000*(.9*16.87) Minimum As as per ACI 10.5 =0.0018bh =0.0018*120*21 4.54in 2 Minimum As doesn't govern. Figure 6.7 b) Interior footing critical section for bending 119 Maximum spacing as per ACI 7.12 is 18 inches Try 9 # 9 bars @ 12 inches center to center As = 9 in2 Re-compute M n a As f y ' c 0.85* f b since 9*60000 0.882in 0.85*6000*120 0.75ab a 0.882 0.053 0.333 d av 16.78 d 0.9*9*60000*(16.87 .882 / 2) 665.37k ft 12000 Therefore the reinforcement provided is enough and M n As f y (d av a ) 2 Mn Mu thus, provide 9#9 bars @ 15 inches center to center both ways. 6.5 Common footing under the two Edge columns meeting at the expansion joint The two footings for the edge columns that come together at the expansion joint are considered as a one and simplified to a single column of dimension 14” x 28 “ ( x and y directions dimensions respectively). This is valid because the expansion joint size between the columns is almost zero compared to the individual footings. Moreover, as the two columns come together the unbalanced moment to at the footing will be zero. Load from superstructure P =510 kips Mx= 0 , My=0 Assuming the following data Bearing capacity of soil = 6000psf = 6 ksf 120 First floor loading is 100 psf = 0.1 psf Density of soil = 120 lb/ft3 weight of soil = 120*5= 600psf =0.6 ksf Thickness of footing =2* column size= 28in Net allowable soil pressure, qn qn 6.0 footpad soil floor floorload 6.0 [ 28 *0.15 5*0.12 0.5*0.15 0.1] 12 4.875 ksf Preliminary area of footing required, Aplim Aplim 510kips 104.6 ft 2 , try a square footing of 10.5 ft by 10.5 ft and 28 inch thick. 4.875ksf Acting net pressure calculation at corners of the footing qact P A Where P= 510 + 1.2*(10.5 ft*10.5ft)*(0.1+0.6+(28/12+6/12)*.15)=586.32 kips and A=110.25 ft2 qact 586.32 5.31ksf 110.25 thickness for two way shear Figure 6.8 Common footing Bearing Pressure distribution 121 Check the thickness for two way shear Assume # 9 bars are used for footing reinforcement dav 28" (3"cover) (bar diameter)=28"-3"-1.128"=23.87 in . The shear perimeter is shown in dashed lines. Figure 6.9 a) Common footing two way shear Average pressure under the footing, qav qav 5.31ksf Acting shear, Vu Vu 5.31*(110.25 ft 2 37.8 * 51.8 ft 2 12 12 582.1 kips Length of critical shear perimeter bo = 2*37.8”+2*51.8 =179.2 in As per ACI , the resistance shear is given by (2 4 ) f ' b d c o av c Vc min ( s d av b ) f c' bo d av o 4 f c' bo d av s = 40 for column at center of footing Critical Section c =long side of column/short side of column =1 2820.74kips Vc min 1500.6kips Vc 1128.3kips 1128.3kips Vc is about two times of Vu reduce the thickness assumed take h = 20 in d av 20" (3"cover) (bar diameter)=20"-3"-1.128"=15.87 in bo 2*(14 15.87 28 15.87) 147.48 Vu 5.31*(110.25 (43.87 1541kips Vc min 663.3kips 616.4kips 12 * 29.87 )) 537.1kips 12 Vc 616.4kips Vu 537.1kips Therefore take thickness D of footing as 20 inches. Check one-way shear 122 The critical section for one way shear lies in the direction where we have the shortest dimension of the assumed combined column size.( i.e. parallel to the longer dimension) qav 5.31ksf Vu 5.31*10.5*(5.25 (7 15.87) /12) 186.45kips Vc 2 f c' bd .85* 2* 6000 *10.5*15.87 /12 1828.56kips Vu Footing is ok against one way shear Figure 6.9 b) Common footing one way shear Critical Section Reinforcement Design For uniformity of the reinforcement in both directions, the most critical section (i.e. parallel to the longer dimension of the column) is considered. qav 5.31ksf (56 /12) 2 acting moment, M u 5.31*[10.5* ] 2 607.11k ft Assume that j= 0.9 Mu 607.11*12000 As = = =9.45 in 2 f y jd av .9*60000*(.9*15.87) Minimum As as per ACI 10.5 =0.0018bh =0.0018*126*20 4.56in 2 Minimum As doesn't govern. Figure 6.9 c) Common footing two way shear critical section 123 Maximum spacing as per ACI 7.12 is 18 inches Try 10 # 9 bars @ 12 inches center to center As = 10 in2 Re-compute M n a As f y ' c 0.85* f b since 10*60000 0.934in 0.85*6000*126 0.75ab a 0.934 0.059 0.333 d av 15.78 d 0.9*10*60000*(15.87 .934 / 2) 693.1k ft 12000 Therefore the reinforcement provided is enough and M n As f y (d av a ) 2 Mn Mu thus, provide 10#9 bars @ 14 in center to center both ways. Development lengths and splices Tension bars As per ACI 318 section 12.2 For # 6 bar and smaller For # 7 bar and greater If the tension reinforcement is a top reinforcement the development length shall be multiplied by 1.3 As per ACI 318-08 section 12.15, the class of the splice is considered to be Class B and thus, Bar splice = 1.3* the values indicated below are rounded to the nearest inch of multiple of five. Bar # Dev. Length(in) Bar splice (in) 6 bottom top 25 35 35 45 7 bottom top 35 45 45 55 8 bottom top 40 55 55 70 9 bottom top 45 60 60 75 124 6.6 Foundation Reinforcement Detailing/ Drawings 125 Note: Cover to reinforcement 3 inches Depth of foundation column considered is 5 feet Concrete 6000psi and steel 60000psi are used The dowels that run from the foundation column into the footing are of the same size and and equal in number to the reinforcements of the foundation column Lean concrete may be placed under footing for smoothening of the surface 126 6.6 Shear Wall Foundation (At Staircase) Figure 6.10 Load at typical floor on wall As we have design for maximum load coming to the wall and we have considered the case of Load coming from Slab at each floors and load coming from staircase these load and wind load is transferred at the bottom of the Footing on that basis we have calculated the Area of footing which is same for each wall 127 Footing are used to transfer loads from the structure to the soil Load Calculation Load from Roof =0.243 kip/ft Load from Flat Plate =5.68 kip/ft Load from Flat Slab = 5.168 kip/ft Load from Slab with Beam = 5.168 kip/ft Load due to wind load= 60.112/25 =2.4 Kips Load due to Flat Plate from Moment = 195.289/25 =7.83 Kips Load due to Flat Slab =193.83/25 =7.75 Kips Load due to Slab and Beam =180.81/25 =7.23 Kips Load due to moment From Staircase = 55.78 x 4/25 =8.92 Kips Load from Staircase Treads = 9.5 x 4/25 =1.52 Kip Load from Staircase slab =0.22 x 2 =0.44 kips Load due to Shear Wall = Density of Concrete x b x d x h=150 x 10/12 x 68.41 =8.55 kip First Floor Live Load = 100 lb/ft Dead Load = 59.37 +1.52 =60.89 Kips…….Adding loads from 1 to 12 Wind Load at the bottom = 0.288 Kips Area Required = Bearing Capacity of the Soil =qa= 6 ksf Assume 2 ft depth of footing 128 Weight of concrete = 150 x 1 x 1 x 2 /1000 =0.3 kips/ft Weight of Surcharge 120 x 1 x 1 x 5/1000 = 0.6 kips/ft qn= qa-weight of concrete- weight of surcharge qn= 6-0.3-0.6 =5.1 kips/ft =11.84 ft2 Area required = Try Footing Area =12 ft2 Width =12/2 = 6ft wide Factored net Pressure qnu= qnu = 7.142 Check the Shear is significant in a wall footing d= 24-cover- 0.5 x bar diameter Cover =3 inch Therefore, d= 20.5” Tributary Area Figure 6.11 Critical section for shear 129 Vu=qnu x (x/12 x1) Vu=7.142 x (10.5/12 x 1) = 6.24 Kips/ft Φ Vc = Φ Φ Vc = = 24.64 kips/ft Vu < Φ Vc Hence depth is ok Therefore a depth as 2 feet and with 6 feet wide Design the reinforcement Tributary area for Flexure Figure 6.12 Critical section for flexure Mu=7.142 (31/12)2 Mu= 23.84 Kips/ft of length 130 Mu= Φ Mn= Φ Ast Fy j d Footing are generally very lightly reinforced therefore assume that J = 0.925 = 0.28 inch2/ft Ast= From ACI Section 10.5.3 and 7.12.2 Minimum Ast=0.0018 =0.5184 inch2/ft Ast=0.0018 Therefore use # 5 Bars Ast of one bar = 0.31 Spacing = 7 inches Diameter of one bar= 0.625 inches Provide #5 bars @ 7” Development Length Bar diameter db=0.625 inches Cover = 3 inch =4 x db=4 x 0.625 =2.5 Bottom Bar x 1 Regular Concrete x 1 Regular Bar x 1 Ld= db = 42.42 x 0.625………………….. ACI 12.2.4 Ld= 26.52’ As we have, 36inch – cover 3inch =33 inch Therefore 26.52”< 33” ……………..Hence Safe Shrinkage & Temperature Reinforcement With Reference to ACI Code 7.12.2.1 Ast=0.0018 = 0.0018 12 Ast=0.5184 inch2 131 132 Therefore provide #5 @ 7” As Per ACI maximum Spacing is 18 inches ……….ACI 7.12 Providing Minimum Area of steel at the Compression Zone Therefore Provide #5 @ 7” in Both direction as it will Avoid Cracking in the Footing In Shear wall Footing I have considered same Footing because these footing were design for maximum load coming From the Slab so it is decided in order to keep same Area of footing for each wall. 6.7 Shear wall Footing Figure 6.13 Plan of shear wall & vertical forces acting on footing 133 Analyze of Shear wall Footing Total Load acting on the footing due to Self weight of Shear wall, Reaction from slabs, elevator & passenger load , machine room is 1935.71 Kips (calculated the above load reaction shown in the figure 1 with the help of Staad- pro software) Moment acting on the footing due to wind is 60.84 k-ft (-Mz) Moment acting on the footing due to slabs – 839.6 k-ft (Mz) Moment acting on the footing due to slabs – 839.6 k-ft (Mx) I have calculated the eccentricity of total load acting on the footing due to individual load ex = -2.32 in ey = -28.26 in Base soil pressure Base soil pressure has been calculated by considering the total load & moments acting on the footing + Where: P= total load (kips) A= Area of footing (ft2) I= moment of inertia of footing y = distance from centre line of footing to farthest end of footing = = 4.548 ksf Hence the calculated soil base pressure is less than the allowable soil bearing capacity (6 ksf). Therefore the assumed area is correct and we can proceed further with the designing. 134 Design Consider a unit strip of footing in both x & z direction and analyze & design it as a beam Figure 6.14 Plan of footing integrated with beams 1, 2, 3 showed in red hatch. Strip in Z- direction Figure 6.15 load & reactions on strip A M1=42.46(k-ft) V1=35.03 k M2=24.625(k-ft) V2=13.175 k 135 M3=1.135(k-ft) 1. First design the strip for the maximum moment & shear to get the safe depth of footing Factored moment Mu= 1.4x42.46 =59.45 k-ft Assume the values of the steel ratio as follow = = = 0.0377 The depth of the footing has been calculated by fybd2 Mu= 59.45x12=0.9x0.019x60x12xd2 d=8.5in 9.5in The overall depth required of strip D for the width b=12in is then D = 9.5+3(cover) +1(dia of bar) + 0.5(half bar dia) = 14” Checking shear capacity Maximum shear in the beams is Vu=49.042k . This shall not be greater than the maximum allowed shear, which is calculated based on the concrete strength , steel strength and the depth of the c/s Vu Vn (10 bwd) Vn= 0.9x10x x12x9.5 = 79.46 kips > 49.042 (Vu=35.03x1.4) 1000 So the depth is satisfactory Recomputed 59.45x12=0.9 by solving with b=12in & d= 9.5in 60x12x9.52 136 = 0.01692 > min = = 0.0033 Area of steel given by: As= bd As=0.01692x12x9.5= 1.93 in2 Check for minimum steel As per ACI code the minimum steel is given by . bw.d = 0.395in2 < As As,min= Provide #9 @ 6” Development length in Tension (ACI Code, section 12.2) ld = 0.04Abfy/ = 0.04x1.128x60000/ =35in Provided ld=35 in 2. Calculate the steel As for moment M2=24.625(k-ft), b=12in, d=9.5in Factored moment Mu= 1.4x24.625=34.475 Mu= fybd2 34.475(12) =0.9x x60x12x9.52 = 0.0074 > min = = 0.0033 Area of steel (As) = 0.0094x12x9.5 = 0.844 in2 Provide #6 @ 6 (As= 0.88in2) Development length in Tension (ACI Code, section 12.2) ld = 0.04Abfy/ = 0.04x0.75x60000/ =23.24in Provided ld=23.5 in 137 Beam1 M1= 7.32(k-ft) V1=87.77 k M2= 14.65(k-ft) Figure 6.16 load & reactions on Beam1 1. Compute the dimensions of beam based on maximum value of Mu. Factored Moment Mu=1.4x14.65 = 20.51(k-ft) Compute the depth of beam by the following equation, assume width of beam (b) = 8” Mu= fybd2 20.51(12) = 0.9x0.019x60xdx19.52 b = 3” (Since the width of wall is 10” so the I have provided the minimum width should not be less 10”, therefore took b=10”) Checking shear capacity 138 Maximum shear in the beams is Vu (87.77x1.4=122.9k). This shall not be greater than the maximum allowed shear, which is calculated based on the concrete strength , steel strength and the depth of the c/s Vu Vn (10 bwd) x10x10.5 = 79.46 kips < 122.9 …………not safe Vn= 0.9x10x 1000 Since the beam failed in shear check, therefore calculate ‘b’ using Vu 123x1000=0.9x10x xbx10.5 => b=18” for b=18” & d=10.5” Recomputed 20.5(12) =0.9x x60x18x10.52 = 0.00243 < min = 0.00333 Area of steel given by: As= bd As=0.0033x18x10.5= 0.63 in2 Provide 6no. #3(As=0.66 in2) 2. Calculate the steel As for moment M1=7.35(k-ft), b=10, d=8.4n Factored moment Mu=1.4x7.35 = 10.248(k-ft) Mu= fybd2 10.248(12) =0.9x x60x18x10.52 = 0.0011 < min = = 0.0033 Area of steel (As) = 0.0034x18x10.5 = 0.642 in2 Provide 3no. #6 (As= 0.66in2) Design for shear Vb = 35.03-2.274x9.5/12 = 33.323 kips 139 Vn= = = 39 kips Check if stirrups are required as per ACI 11.5.5 Vc=2 bwd =17.67 kips Since Vn>Vc Therefore stirrups are required Check selected stirrups for anchorage and maximum spacing Try No. 3 double leg stirrups with fy = 60000psi in which case Av= 0.22 in2 . Since the bar used for stirrups is less No. 6 ACI recommends that the stirrups be anchored by a 90 0 hook around a bar.As per ACI 11.4.5, the maximum spacing shall be the smaller of the following. Smax Therefore, Smax = 4.75 in Compute the required stirrup spacing to resist the design shear forces For vertical stirrups S= = = 31.87” Use double leg # 3 bars at a spacing s=4.75” in all over the beam. As this is the maximum shear, the same spacing of stirrup is to be used all over the beam. Beam 2 M1=661.5(k-ft) V1=271.67 k M2=330.75(k-ft) V2=170.85 k 140 Figure 6.17 load & reactions on Beam 2 1. Compute the dimensions of beam based on maximum value of Mu. Factored Moment Mu=1.4x661 = 926.1(k-ft) Compute the depth of beam by the following equation, assume width of beam (b) = 24” fybd2 Mu= 926.1(12) = 0.9x0.019x60x24xd2 d = 23.5” 3”(cover) + 0.5”(half of dia.) = 27” Checking shear capacity Maximum shear in the beams is Vu(271.67x1.4=380.4k) . Vu Vn (10 bwd) x24x23.5 = 393.2 kips >380.4 kip ………safe Vn= 0.9x10x 1000 Recomputed for b=24” & d=23.5” 926.1(12) =0.9x x60x24x23.52 = 0.011 > min = 0.00333 Area of steel given by: As= bd 141 As=0.011x24x23.5= 6.64 in2 Provide 5no.s #9 & 3no. #7 (Ast =6.8 in2) 2. Calculate the steel As for moment M2=330.75(k-ft), b=24, d=23.5n Factored moment Mu=1.4x330.75 = 463.05(k-ft) fybd2 Mu= 463.05(12) =0.9x x60x24x23.52 = 0.00815 > min = 0.0033 = Area of steel (As) = 0.00815x24x23.5 = 4.6 in2 Provide 7no.s #7 & 1no. #6 (Ast =4.64in2) Design for shear Vb = 271.37-35.03x23.5/12 = 202.76 kips Vn= = = 238.55 kips Check if stirrups are required as per ACI 11.5.5 Vc=2 bwd =87.37kips Since Vn>Vc Therefore stirrups are required Check selected stirrups for anchorage and maximum spacing Try No. 3 double leg stirrups with fy = 60000psi in which case Av= 0.22 in2 . Since the bar used for stirrups is less No. 6 ACI recommends that the stirrups be anchored by a 90 0 hook around a bar. As per ACI 11.4.5, the maximum spacing shall be the smaller of the following Smax Therefore, Smax = 11 in 142 Compute the required stirrup spacing to resist the design shear forces For vertical stirrups S= = = 205.1” Use double leg # 3 bars at a spacing s=11” in all over the beam. As this is the maximum shear, the same spacing of stirrup is to be used all over the beam. Beam 3 M1=185.5(k-ft) V1=85.64 k M2=92.75(k-ft) V2=171.28 Figure (6) load & reactions on Beam (3) 1. Compute the dimensions of beam based on maximum value of Mu. Factored Moment Mu=1.4x185.5 = 260(k-ft) Compute the depth of beam by the following equation, assume width of beam (d) = 10.5” Mu= fybd2 260(12) = 0.9x0.019x60xbx10.52 b = 32” Provided b=34” for shear to come safe Checking shear capacity 143 Maximum shear in the beams is Vu (171.28x1.4=239.8k) . Vu Vn (10 bwd) x34x10.5 = 248.9 kips >239.8 kip ………safe Vn= 0.9x10x 1000 for b=34” & d=10.5” Recomputed 260(12) =0.9x x60x34x10.52 = 0.017 > min = 0.00333 Area of steel given by: As= bd As=0.017x32x10.5= 5.714 in2 Provide 5no. #9 & 1no. #8 (As = 5.79 in2) 2. Calculate the steel As for moment M2=92.75(k-ft), b=34in, d=10.5in Factored moment Mu=1.4x92.75 = 129.85(k-ft) Mu= fybd2 129.85(12) =0.9x x60x34x10.52 = 0.00808 > min = = 0.0033 Area of steel (As) = 0.00808x34x10.5 = 2.89 in2 Provide 5no. #7 (As= 0.3in2) Design for shear Vd = 171.28-13.17x10.5/12 = 159.75 kips Vn= Vc=2 = = 187.94 kips Check if stirrups are required as per ACI 11.5.5 bwd =55.30 kips Since Vn>Vc Therefore stirrups are required 144 Check selected stirrups for anchorage and maximum spacing Try No. 3 double leg stirrups with fy = 60000psi in which case Av= 0.22 in2 . Since the bar used for stirrups is less No. 6 ACI recommends that the stirrups be anchored by a 900 hook around a bar. As per ACI 11.4.5, the maximum spacing shall be the smaller of the following Smax Therefore, Smax = 5.25 in Compute the required stirrup spacing to resist the design shear forces For vertical stirrups S= = = 104.5” Use double leg # 3 bars at a spacing s=5.25” in all over the beam. As this is the maximum shear, the same spacing of stirrup is to be used all over the beam. 145 7. Cantilever Retaining Wall 7.1 Introduction Retaining walls are structures that support backfill and allow for a change of grade. For instance a retaining wall can be used to retain fill along a slope or it can be used to support a cut into a slope. Retaining wall structures can be gravity type structures, semi-gravity type structures, cantilever type structures, and counter fort type structures. Walls might be constructed from materials such as fieldstone, reinforced concrete, gabions, reinforced earth, steel and timber. Each of these walls must be designed to resist the external forces applied to the wall from earth pressure, surcharge load, water, earthquake etc. Cantilever retaining wall consists of vertical wall, the stem, supported on a footing. The front and rear end of the footing (or base) are termed the toe and heel, respectively. The weight of the fill directly over the heel of the foundation stabilizes the wall, that is, prevents it from sliding outward and overturning .When the lateral thrust is large, some designers may add the key, a short vertical cantilever, to the base of footing to increase resistance to sliding Drainage System At times, the water pressure together with the soil pressure of a submerged backfill will produce a much larger forces than a dry backfill. To lower these forces engineers provide 146 drains or weep holes to reduce the buildup of water pressure behind walls. We have provided the perforated soil pipe surrounded by a graded, stone filter. A filter prevents inflow of sand or silt that would clog the drain. In our project we have provided a perforated pipe 8” in diameter lay along the base of the wall and surrounded by gravel. Fig 7.1 Drainage System in Retaining Wall Specification: Provided perforated 8” diameter pipe laid along the base of the wall &surrounded by gravels (stone filter) Purpose To release the hydrostatic pressure. 147 Figure (7.3) free body of soil & pressure 148 Height of wall from G.L = 8’ Live load =100psf Soil Density ( =120lb/ft³ Allowable soil bearing capacity = 6ksf Angle of internal friction ( fy = 60 ksf fc = 4 ksf 1. Using the Rankin equation: Ca = 1-sin/1+sin = 1- = 0.33 2. Determinations of the dimensions of the retaining wall:Height of wall (h) = 8’+3’= 11’ Base thickness = h/12 to h/10 = 0.92’ to 1.1’ Base length = 0.5h to 0.7h = 5.5’ to 7.7’ = 6.6’ (assumed) Stem thickness = 0.08h to 0.1h = 0.9’ to 1.1’ = 10‘(assumed) Toe projection phase of stem = 0.17’ to 0.125’h = 1.87’ to 1.375’ = 1.7’ (assumed) Base analysis on the 1’ thick slice of wall 3. Factor of safety against overturning:Calculate the actual unfactored forces acting on the retaining wall, first those acting to overturn the wall P1 = Ca.W = 0.33x 0.1 = 0.033 kip/ft³ P2 = Ca h = 0.33x0.12x11= 0.436 kip/ft³ Ha1 = 0.033x11 = 0.363 kip……………………………….. arm 11/2 = 5.5’ Ha2 = 0.436x11/2 = 2.4 kip………………………………....arm 11/3 = 3.67’ 149 Overturning moment about ‘a’ due to horizontal forces:Ma = (0.1815x1.5’) + (2.4x11/3) = 9 k-ft Balancing Moment against overturning:- Forces(kip) Arm(ft) Moment(k-ft) W1= 0.834’x9.8’x0.15 = 1.23 2.12 2.16 W2= 6.6’x1’x0.15 = 1 3.3 3.3 W2= 9.8’x 4.07’x0.12= 4.79 4.57 21.9 W4 = 0.1x4.07 = 0.407 4.57 1.86 W = R= 7.547 Ma= 29.67 Table 7.1 Vertical forces and moment acting at the toe of footing F.O.S = against overturning = Ma R = 29.67 = 3.29 > 2 9 4. Calculate base pressure:Take moments about the toe end ‘a’ to determine the location of the resultant ‘R’ of the vertical forces. x = Ma - h(y) = Balancing Moment - overturning moment R R x = 29.67 - 9 = 2.8’>2.2’ (6.6’/3 = 2.2’) 7.547 The eccentricity ’e’ = 6.6/2 - 2.8 = 0.5’ The resultant ’R’ acts within the middle third of the base and has an eccentricity e = 0.5’ from the centre of the base. Assuming compressive stresses act over the entire base, compute the magnitude of the soil stresses at each end of the footing by direct &bending stresses produced by ‘R’ 150 p = R + ( R.e) .c A I where R = 7.547 kips A = 6.6x1 ft2 c = 6.6/2 ft I= ft4 Substituting above terms into above equation, Pmax = 1.66 ksf Pmin = 0.62 ksf Since the maximum value of soil pressure (at the toe) is less than the allowable bearing capacity of 6 ksf, the soil is not overstressed. 5. Factor of safety against sliding: - Passive pressure is neglected unless a key is provided Forces causing sliding = Ha1 + Ha2 = 0.363 + 2.4 = 2.736 kip Resisting forces = R ………………… (Assume = coarse grained soil without silt) = 0.5x7.545 = 3.77 kip F.O.S against sliding = R Ha = 3.77/2.676 = 1.36 < 1.5 So, in this case, key should be provided to develop passive pressure larger enough to resist the excess forces that causes sliding. In the calculation of the passive pressure ,the top foot of the earth at the toe side is usually neglected , leaving a height of 2ft. Assume a key depth ‘t’=1.25’ and width ‘b’= 1.25’ Cp Hp = 1+sin = 1.5/0.5 = 0.3 1-sin = ½ Kp(h’+t)² 151 = ½ x 3x 0.12 x (2+1.25)² = 1.9 kip The sliding occurs on the surfaces ac, cd, df Figure 7.4 Footing Details Frictional forces (F) = (R1.1) + (R2.2) R1= Reaction on AC = 2.12 = 2.69 kip R2= Reaction on CDF = 5.32 = 4.136 kip F = (0.7) x 2.69 + (0.5) x4.136 = 3.951 kip Hence, the total Resisting force (F+Hp) = 3.951+1.9 = 5.85 kip F.O.S against sliding = Resisting force Ha = 5.85/2.736 = 2 > 1.5.…………………….SAFE 152 DESIGN 6. Design of wall (Stem):-Design the stem for shear and moment created by lateral earth pressures using a load factor of 1.7 .The thickness of the stem is generally controlled by moment. The critical section for bending moment is at the bottom of wall, Height of wall above footing = 11’- 1’ = 10’ Moment at base of stem (Ms):-- Ha1= 0.033x10 = 0.33 kip (Due to surcharge) Ha2= ½ x 0.396x10 = 1.98 kip (Due to lateral earth pressure) V= 2.313 kip Ms = 0.3(10/2) + 1.98(10/3) = 8.24 k-ft Mu(at the bottom of wall) = 1.7(Ms) = 1.7x8.24 = 14 k-ft Check for depth:Mu = fybd² 12x14 = 0.9x0.014x12x60xd² (1 - 0.014x60) 1.7x5 d = 4.6” 5” Hence, the total depth of stem’D’ = 5+2+0.5 = 7.5”< 10” (what assumed previously) Check for critical shear:Vc = 2 = 0.85x2x bd ) x12x7.5 = 11.85 kip Vu = 1.7(V) = 1.7x2.313 = 3.93 kip Hence Vu < Vc …………………………Shear capacity is O.K 153 Steel Requirement Reinforcement at internal face:o Main Reinforcement:Ru = Mu = 14x1200 = 248.88 bd² 12x(7.5)² %= 0.0048 Ast =%bd = 0.0048x12x7.5 Ast, provided = 0.432 0.465 in² Providing #5@8” [Vertical steel] Development length in Tension (ACI Code, section 12.2) ld = 0.04Abfy/ = 0.04x0.31x60000/ =10in< 21in Provided ld=21 in (min development length) o Distribution Steel:Minimum Steel = 0.0025bd = 0.0025x12x7.5 = 0.225 Divided the above steel into internal and external face equally. Mini Steel (each face) = 0.1125in²............ [ACI - 14.3.4] Provide #3 @ 11’ Development length in Tension (ACI Code, section 12.2) ld = 0.04Abfy/ = 0.04x0.11x60000/ =3.5in< 12in Provided ld=12 in (min development length) Reinforcement at external face:Main reinforcement:Ast,mini = 0.0012xbxd = 0.0012x 12x7.5 = 0.11in² Provide #3 @12” 154 Development length in compression (ACI Code, section 12.3) ld = 0.02Abfy/ = 0.02x0.11x60000/ =1.8in< 8in Provided ld=8 in (min development length) 7. Design of Heel The upward soil pressure is neglected as it will reduce the effect of the backfill & concrete on the heel. The total load on the heel: Vu = 1.7(Rw) + 1.4(Wsoil) + 1.4(Wconc.) = 1.7x0.407+1.4x4.79+1.4x4.07x0.15 = 8.25 kip Mu (at face of wall) = 8.25x2.035 = 16.8 k-ft Check for shear (depth required for shear) Vc = 0.85(2( ) bd Vc = Vu 0.85(2 )12xd = 1000x8.25 d = 6.4” (effective depth) Required depth = 6.4”+3”+0.5” = 10” = 10” (assumed) Steel reinforcement:Ru = Mu = 16.28x12000 = 232.526 bd² 12x8.5² % = 0.45 Ast = 0.0045x12x8.5 = 0.46in² Provide #5 @8” Development length in Tension (ACI Code, section 12.2) ld = 0.04Abfy/ = 0.04x0.31x60000/ =9.6in< 21in Provided ld=21 in (min development length) 155 8. Design of the Toe The toe of the base acts as a cantilever beam subjected to upward pressure. The toe is subjected to upward pressure from soil &downward pressure due to self weight of the toe slab. The critical section for shear is at the distance’s’ from the front face of the stem. Vu = 1.7(1.6+1.48) x0.825’ - 1.4(1’x0.15’0.835) 2 = 2.34 kip (this is less than Vc) Mu = 1.7[1.35x1.7² + (1.6-1.35) x1.7 (2/3 x1.7)] -- 1.4[1x0.15x 1.7² ] 2 2 2 = 3.45 (k-ft) Steel reinforcement:Ru = Mu = 3.45x12000 = 47.75 bd² [ took mini % = 0.003 from steel table ] 12x8.5² Ast = Ast = 0.204in² Provide #4 @12” Development length in Tension (ACI Code, section 12.2) ld = 0.04Abfy/ = 0.04x0.5x60000/ =15.5in Provided ld=16 in Figure 7.5 Critical section for shear in toe 156 157 158 8 Green Engineering 8.1 Introduction Green engineering is the design, commercialization, and use of processes and products, which are feasible and economical Helps in Minimizing Environment aspect generation of pollution at the source risk to human health and the environment Green engineering initially cost more but later on it gets benefited. As every year USA generates billions tons of waste as the managing waste cost hundred of billions of dollars as we can see following graph which displays the increase in environmental regulations from 1870 to present, demonstrates this trend. Figure 8.1 Increases in Environmental Regulation Although the number of regulations was on the rise in the mid 60's, the majority of the regulations (75%) were passed after 1970 following the creation of the U.S. EPA 159 As industry continues to expand and permissible exposure limits continue to decrease, waste treatment and the associated risk are becoming less cost efficient and more difficult to handle. The figure below depicts the general trend observed over time of reduced emission limits in conjunction with increased industrial growth. Figure 8.2 Graphs on Emission in Industrial Engineers have used several strategies to minimize the impact of chemical processes on human health and the environment. By selecting chemicals that have low toxicity, potential hazards are eliminated and chemical releases are prevented, thereby reducing chemical exposures. Thus, environmentally conscious design reduces risks. http://www.epa.gov/oppt/greenengineering/pubs/whats_ge.html What Makes a Building Green? A green building, also known as a sustainable building, is a structure that is designed, built, renovated, operated, or reused in an ecological and resource-efficient manner. Green buildings are designed to meet certain objectives such as Protecting occupant health Using energy, water, and other resources more efficiently and reducing the overall impact to the environment What Are the Economic Benefits of Green Buildings? A green building Initial cost is high but saves through lower operating costs over the life of the building. 160 Some benefits, such as improving occupant health, comfort, productivity, reducing pollution and landfill waste are not easily quantified. Consequently, they are not adequately considered in cost analysis. For this reason, consider setting aside a small portion of the building budget to cover differential costs associated with less tangible green building benefits or to cover the cost of researching and analyzing green building options. Even with a tight budget, many green building measures can be incorporated with minimal or zero increased up-front costs and they can yield enormous savings . What Are the Elements of Green Buildings? Energy efficiency Materials efficiency Water efficiency Energy efficiency Passive design strategies can dramatically affect building energy performance. These measures include building shape and orientation, passive solar design, and the use of natural lighting. Develop strategies to provide natural lighting. Studies have shown that it has a positive impact on productivity and well being. Install high-efficiency lighting systems with advanced lighting controls. Include motion sensors tied to dimmable lighting controls. Task lighting reduces general overhead light levels. Use a properly sized and energy-efficient heat/cooling system in conjunction with a thermally efficient building shell. Maximize light colors for roofing and wall finish materials; and use minimal glass on east and west exposures. Minimize the electric loads from lighting, equipment, and appliances. Consider alternative energy sources such as photovoltaic’s and fuel cells that are now available in new products and applications. Renewable energy sources provide a great symbol of emerging technologies for the future. 161 Materials Efficiency Selection of sustainable materials by evaluating several characteristics such as reused and recycled content, zero or low off gassing of harmful air emissions, zero or low toxicity, sustainably harvested materials, high recyclability, durability, longevity, and local production. Such products promote resource conservation and efficiency. Using recycled-content products also helps develop markets for recycled materials that are being diverted from California's landfills, as mandated by the Integrated Waste Management Act. Use dimensional planning and other material efficiency strategies. These strategies reduce the amount of building materials needed and cut construction costs. Water Efficiency Design for dual plumbing to use recycled water for toilet flushing or a gray water system that recovers rainwater or other non potable water for site irrigation. Minimize wastewater by using ultra low-flush toilets, low-flow shower heads, and other water conserving fixtures. http://www.ciwmb.ca.gov/greenBuilding/Basics.htm 8.2 What material we have consider in Commercial Building Project Table 8.1 Materials considered in green engineering Materials Function Application Glazing Curtain Wall Weather protection & Glass on all exterior surface System Insulation Roof Garden Plantation & Aesthetics Sewage Treatment Plant To Generate Methane as an Drainage Treatment of on roof energy Building Paints Environmental Friendly All interior portion Lighting Less Energy Consumption Both Interior & Exterior Water Proofing Water proof structure For Concrete & Masonary 162 Glazing Curtain Wall System: The glass and aluminum curtain wall is found in city centres on many new buildings and it is quite popular as a cladding and exterior wall on all types of commercial, industrial, institutional and residential buildings. The curtain wall is characterized with colored vision and spandrel glass areas, a grid of aluminum caps and most recently with metal or stone spandrel covers It is also combined with other types of cladding systems such as precast, brick or stone to create attractive and durable building facades. The curtain wall comprises a complete cladding and exterior wall system with the exception of the indoor finishes. It is generally assembled from aluminum frames, vision glass and spandrel glass (or metal or stone) panels to enclose a building from grade to the roof. Function Airtight and weather resistant Air leakage control Rain Penetration Control Heat Loss Condensation Control Fire Safety System Adopted for Fixing Glass System The Unitized Curtain Wall A glass and aluminum curtain wall fabricated and installed as a panel system is referred toas a unitized curtain wall system. A unitized curtain wall will have the same components as a stick built curtain wall system. It will comprise aluminum mullions, an IGU and a spandrel panel mounted in a prefabricated aluminum frame. However, instead of assembling the glass and aluminum curtain wall in the field, most of the system components are assembled in a plant under controlled working conditions. This promotes quality assembly and allows for fabrication lead-time and rapid closure of the building. 163 Infiltration allowance Air infiltration is the air which passes through the curtain wall from the exterior to the interior of the building. The air is infiltrated through the gaskets, through joints which are opened as we know allowance rate is very low as per US specification as joints should be between horizontal & vertical mullions, through weep holes, and through imperfect sealing air can easily come. As per The American Architectural Manufacturers Association (AAMA) is the main body how looks after the specification related to Glass and which has sets the acceptable levels of infiltration through a curtain wall. This limit is expressed (in America) in cubic feet per minutes per square foot of wall area at a given Test pressure. As per standards it is followed practice less than 0.6 CFM/sq ft as acceptable http://en.wikipedia.org/wiki/Curtain_wall#Fire_safety Components Involved are: Mullions vertical Frame & rails horizontal mullions Vision Glass, insulation Hardware components – Anchors, Aluminum connector, Settings blocks, Corner blocks, Pressure plates, caps, gaskets Fixing System The unitized system is assembled on the building as panels. The mullions and rails are fabricated as half sections instead of tubular sections, which mate at assembly ime to form the curtain wall system. The panels are installed in shingle fashion, starting from the bottom of the building and going around each floor and up the building. While the unitized system offers many advantages with respect to quality assembly and speed of on building closure, there is one design concern with respect to installed performance and durability. Installers should ensure that the air seals are properly installed between the 164 split mullions. Nevertheless, the unitized system is now as popular as the stick system according one Figure 8.3 Typical Unitized Curtain Wall System Figure 8.4 Typical Unitized Curtain Wall System Assembled product 165 Function – 1. Air leakage control To perform satisfactorily, a cladding an exterior wall system must meet several performance requirements. These include air leakage control (the air barrier function), vapour diffusion control (the vapour barrier function – not the same as the air barrier function), heat loss/gain control (insulation and thermal breaks), rain and melt water penetration control(the rain screen principle). In addition, the curtain wall must accommodate various differential movements. The most critical of the performance requirements is air leakage control. The leakage of air through a curtain wall system in winter may result in excessive ice buildup on aluminum caps, at parapets or soffits. The ice can grow to become a safety hazard to persons and property below. Air leakage also causes condensation in glazing cavities to the Detriment of the IGUs and it can corrode back pans and fasteners. The leakage of air at the glass aluminum joint is minimized with either a wet or dry seal. In a unitized system, the mullions are split and therefore include an additional air barrier joint between the half mullions. This joint is usually hidden and inaccessible once assembled. Fig. 8 – Air 166 Figure 8.5 Typical Unitized Curtain Wall System Air Vapour Barrier 167 The air leakage rate through a curtain wall fabricated for the United States market is limited to 0.3 litres/sec*metre2 at 75 Pa (0.06 cfm per ft2 at 1.57 lbs/ft2) air pressure difference. Location 2. Rain Penetration Control Like any wall system, the curtain wall system must prevent the penetration of rain or melt water to the inside of the building. Being constructed of glass, aluminum, steel, fibrous insulation and sealants, the components have no ability to absorb and release even the most incidental amounts of water penetration. While some types of insulation can absorb moisture, very little moisture enters the back pan area. Also, because most of the materials comprising the curtain wall are corrosion resistant, water does not damage the system materials, except the seals of the IGUs if they remain wetted for long periods of time. To enhance the rain penetration control of a glass and aluminum curtain wall system, the rain screen principle is applied. The rain screen principle incorporates various features to control: • Direct entry of rain or melt water, • Capillary action, • Surface and cavity drainage, • Pressure equalization of the glazing cavities. In a stick built system, resistance to the direct entry of rain and melt water penetration is provided by the outside seal or gasket at the glass-to-cap joints. However, should a minor Amount of rain or melt water penetrate through the head, jamb or sill gasket or seal of the Vision glass, it is channeled sideways and downwards via the jamb cavity to the sill glazing cavity below. The rainwater is then diverted horizontally by the corner blocks the 168 drain holes in the pressure plates and into the curtain wall snap caps to drain to the outside. 3 Fire Safety Fire stopping at the perimeter slab edge which is a gap between the floors and the back pan of curtain wall is essential slow the passage of fire and combustion gases between floors. Spandrel areas must have non combustible insulation at the interior face of the curtain wall. As per some building code requires the mullion is rapped at in heat insulation near the ceiling to prevent the mullions from melting and spreading the fire to the floor above. It is important to note that the fire stop at the perimeter slab edge is considered a continuation of the fire resistance rating of the floor slab. The curtain wall itself. However, is not ordinarily required to have a rating .To avoid Fire and Smoke Migrations beyond engaged compartment. As curtain wall by it is nature prevents the Fire hence fire safety is maintained using curtain wall http://en.wikipedia.org/wiki/Curtain_wall#Fire_safety Vendor www.aamanet.org or call or write AAMA at; Tel. (847)303-5664; Fax (847) 303-5774 1827 Walden Office Square, Suite 104 Schaumburg, Illinois, 60173. Analysis of curtain wall system All exterior walls, of whatever materials, are subject to, and must withstand the ravaging effects of nature. These nature forces are sunlight, temperature, water, wind and gravity. Except for gravity, the intensity and relative significance of these forces vary some what 169 from one region to another, but all of them are been considered, and their effects provided for, in all location Approximate Weight of Architectural Flat Glass The table below provides approximate weights of architectural flat glass by thickness designations as published by North American manufacturers: Table 8.2 Glass weight Glass Thickness 2.5 3 4 5 6 8 10 12 16 19 1.2 1.6 2 2.4 3 4 5 6.4 8.1 9.8 Designation (mm) Approximate weight lb/ft2 2945 SW Wanamaker Drive, Suite A Topeka, KS 66614-5321 (785) 271-0208 Fax: (785) 271-0166 www.glasswebsite.com Weight consideration for design in project Curtain Wall is a term used to describe a building façade which does not carry any dead load from the building other than its own dead load, and to transfer horizontal loads (wind loads) applied on the curtain wall. These Loads, are transferred to the main building Connection through hardware connection at floors or columns of the building .a curtain wall is designed to resist air and water infiltration, wind force acting on the building. Hence we can see Fig 8.6 how load is transferred floor to floor as mentioned below complete load calculation with some approximation the panel size and connection we have calculated the load transferred into beams 170 Figure 8.6 Load Transfer Load due to glass curtain wall Weight of a 10mm (3/8 in) glass is 5psf (glass information bulletin) Weight of connections, mullions, capping = 0.5*5= 2.5 psf Total weight of glass curtain wall = 7.5 psf Specification of Glass We have consider Panels for Glass as 10mm thick For Ground Floor to First Floor we have 26 feet height. Therefore we have divided the height of the floor into two parts . 5 Panels .Below Figure represents the Glass panel Sizes for Each Floor we have provided 171 Figure 8.7 Glass Panel Sizes at different floors Roof Garden Aesthetic Benefits • Green roofs are much better looking than asphalt or tar. • Natural views create more productive, healthy, happy, creative, relaxed people. • Green roofs expand the usefulness of buildings via patios, gardens and vistas. How it is fixed? It is a modular system 172 Figure 8.8 Components of Roofing System LiveRoof module is filled to the top of Soil Elevator with LiveRoof engineered soil. LiveRoof Plants are grown to maturity approximately 1 inch above the LiveRoof module. Placed directly into the roof as it is modular system it can be replaced easily Why Use LiveRoof System for Green Roof? It is an instant Green roof Saves Money rather than farming on the roof Drainage pattern is good please refer the figure below Easily changeable 173 Figure 8.9 Positive Drainage for healthy roots Figure 8.10 Fixing Method 174 Advantages The Live Roof® system is superior in design and implementation to both conventional green roofs and to other modular green roof systems. Specific benefits include a better aesthetic presentation and instantly functional evaporative cooling (instantly green vs. brown and no multi-year grow in period), substantially lower maintenance, elimination of wind and rain erosion, simple installation, expertly engineered soil and plant selections, durable indefinite-lasting components Specification SIZE: Module: 1’ x 2’ x 3” (soil height approximately 4”) Soil fills soil elevator, plants and soil obscure container edges MATERIAL: 100% post-industrial recycled polypropylene 100 mil. thick walls WATER DISPERSAL: Approximately 7 gal. per min. per lineal foot. COLOR: Black WEIGHT VEGETATED (fully saturated): Approx. 27-29 lbs./sq. ft DRAINAGE: Positive drain holes, placed at lowest point in container. Avoids root rot associated with water reservoirs. Special Hi-Flow option available SOIL MEDIA: It is recommend proprietary LiveRoof® specified engineered soil, enhanced German FLL specifications, 93+% (by dry weight) inorganic content for minimal shrinkage/decomposition ACCEPTABLE PROTECTIVE UNDERLYING MATERIALS: Modules are typically placed directly upon a heavy duty (HDPE, Polypropylene, TPO, EPDM or recyclable PVC) slip sheet/root barrier of 45-60 militre thickness with effectively bonded seams. This is placed as an additional protective barrier above roof waterproofing membranes. Alternatively low profile drain boards work well and manufacturers of cold fluid applied reinforced urethane membranes typically warrant their systems for use in conjunction with LiveRoof® system. IRRIGATION SYSTEM: Generally not needed, but recommended for backup during prolonged hot dry windy weather patterns. Simple overhead system, spigot/hose/sprinkler 175 or drip irrigation systems are inexpensive and effective insurance. Irrigation requirements are dependent on plant selection. If lightweight module is used, irrigation will be essential EDGE TREATMENTS: Co engineered Permaloc® aluminum L-shaped unaffixed edging recommended. PLANTS: See LiveRoof®.net for grower in your region, for specific recommendations. MAXIMUM STACKABLE HEIGHT: LiveRoof® modules are designed to be stacked on their sides so as to protect the Soil Elevator TM holders.http://liveroof.com/ Sewage Treatment Plant Fig 8.11 Scheme representation of Sewage Treatment Plant 176 Sewage Treatment Plant is basically clean the sewage comes into it is done basically as show in scheme representation here by Bioelectrolytic Process here main process is run by Electro tank were electrolysis takes place. Electrolysis is a technique involving the passing of electricity through the effluent. The electric current distabilize dissolved colloidal particles and alters the charge on suspended particles permitting their separation Benefit of Electrolytic Treatment System 1 Non Chemical Treatment as per green engineering specification 2 No Aeration and no MLSS maintained 3Result in pathogen free disinfected water 4Toxicity easily handled 5Sludge is pathogen free, Easy to dispose & non hazardous to the environment 6 High Performance to cost ratio 7 Noiseless system Advantages It generates Methane which can be used as a Source of Energy. We can use the piping to send to appropriate location It is an Custom make and modular in size Maintenance and Operation cost is economical It maintains the BOD & COD level of Water is obtained which give the clean water as per environmental department required Location: It is fixed in parking lot and very little space is occupied as it is a compact system Quantity of water treated is 300 KLD (Approximation as per size of Project) Paints Consideration for most interior paints is their potential impact on occupant health. To this end, very-low-VOC or zero-VOC paints are generally preferred, though some 177 chemically sensitive people find that even these can be difficult to tolerate. Note that liquid carriers (including water and exempt VOCs) are usually excluded when stating VOC levels, which are expressed as grams of VOC per liter of VOC-plus-paint-solids. Most zero-VOC paints still use colorant systems that contain VOCs, so custom-coloring will increase emissions. Some paints are made from minimally processed plants and minerals; while these products may contain relatively high levels of VOCs, they may not be as troublesome as the compounds released from petrochemical-based paints. Products that are less than 50 grams of VOCs per liter is recommended Sherwin-Williams has increased the quality and depth of its paint inventory with the introduction of two new industrial paints with low levels of volatile organic compounds (VOCs). The Pro Industrial 0 VOC waterborne acrylic formula and the alkyd (oil-based) Enamel 100 are designed for interior or exterior use in healthcare, commercial, industrial, or other applications where paint will be exposed to high traffic, dirt, and moisture. These Paints are useful for Interior & Exterior wall painting so that it has special properties which are helpful human environment as it has low volatile organic compounds (VOCs) Lighting Fluorescent lamps have long been preferable to incandescent lighting, relative to energy efficiency. New developments with fluorescent technology, including the high-efficacy T5 lamps, have pushed the energy efficiency envelope further. Recently, attention has also been paid to the mercury content of fluorescents and the consequences of mercury releases into the environment. As with all resource use and pollution issues, reduction is the best way to limit the problem. Even with low-mercury lamps, however, recycling of old lamps remains a high priority As these kinds of lamps is provided in the passage of the building and staircase and common area in the building as it saves lot of energy and gives the same output hence we save a good amount of energy as 178 Waterproofing Waterproof Coatings for Concrete and Masonry.While most conventional concrete sealers and waterproofing agents have very high VOCs, some products react with the concrete or otherwise provide a seal without resorting to solvents that emit VOCs. Green Products contains zero VOCs, either nominally or actually. .Product for Waterproofing: Aquafin-IC Crystalline Waterproofing Company: Aquafin, Inc. Aquafin-IC is a penetrating, inorganic, cementitious material used to permanently waterproof and protect new or existing structurally sound concrete Application is on Concrete structure or wall were we can apply waterproofing component and increase its life span were no water leakage takes place http://www.buildinggreen.com/menus/drillBC.cfm?BuilderCategoryI 179 9. Material (Concrete) usage Estimation Components Quantity in (ft3) Slabs 75000 Beams 6973 Columns 5488 Staircase 1750 Shear Wall with Staircase 5667 Shear Wall with Elevator(2) Footing for Shear Wall with Staircase Footing for Shear Wall with Elevator (2) Footing Under Column Retaining wall 11861.54 1200 2434.86 7232 15688.52 Total Concrete Quantity = 133294.9 Ft3 180 References Books ACI Code International building Code –IBC Load calculation & Specification ASCE- American Society of Civil Engineering Christian Meyer, Design of Concrete Structures, Prentice Hall, New Jersey Christian Meyer, Design of Concrete Structures, Prentice Hall, New Jersey Brian Boughton, “Reinforced Concrete Detailer Manual”-Detailing of Staircase , Granada Publication, London, 3rd Edition Phil M Ferguson, John E. Breen, James Jirsa, “Reinforced Concrete Fundamental”, John Wiley & sons Publication, New York Kenneth Leet, Dionisio Bernal, “Reinforced Concrete Design” ,The McGraw-Hill Companies, INC, New York, 3rd Edition M.Nadim Hassoun, “Design of Reinforced Concrete Structures”, PWS Engineering, Boston James G Macgregor ,“Reinforced Concrete Mechanics and Design”, (2nd edition) by Prentice hall, A Simon and Schuster company, Upper saddle river ,NJ – 07458 Jack C.McCormac, “Design of Reinforced Concrete” (4th edition),AddisonWesley, California. 181 Sites Expansion joint http://www.copper.org/homepage.html) 6 Elevator Load and Specification, Mitsubishi Company, www.mitsubishielevator.com/ Green Engineering-Introduction http://www.epa.gov/oppt/greenengineering/pubs/whats_ge.html Green Building http://www.ciwmb.ca.gov/greenBuilding/Basics.htm Glass Vendor: AAMA at; Tel. (847)303-5664; Fax (847) 303-5774 1827 Walden Office Square, Suite 104 Schaumburg, Illinois, 60173. www.aamanet.org http://en.wikipedia.org/wiki/Curtain_wall#Fire_safety www.glasswebsite.com Green engineering Other Component http://www.buildinggreen.com/menus/drillBC.cfm?BuilderCategoryID=23 Aesthetics –Green roof Live roof System http://liveroof.com/ Sewage Treatment Plant, www.superklean.in 182 183