STUDY & DESIGN WORKS FOR THE PROJECT
Steel Structural Hangar
AlRehab AlOla Co.
DESIGN BASIS REPORT
STRUCTURAL
November, 2021
TABLE OF CONTENTS
1
STRUCTURAL DESIGN CRITERIA ...................................................................................... 2
1.1 CODES, STANDARDS AND PUBLICATIONS ......................................................... 2
1.2 LOADS .............................................................................................................................. 2
1.2.1 Dead Loads ............................................................................................................ 2
1.2.2 Live Loads............................................................................................................... 2
1.3 SEISMIC LOADS................................................................................................................ 3
1.4 WIND LOADS .................................................................................................................... 3
1.5 TEMPRETURE VARIATIONS..................................................................................... 3
1.6 GEOTECHNICAL DETAILED DESIGN REQUIRMENT AND SOIL
DESIGNPARAMETERS ......................................................................................................... 4
1.7 LOAD COMBINATIONS............................................................................................... 5
1.7.1 FACTORES LOAD COMBINATIONS ................................................................ 5
1.7.2 WORKING LOAD COMBINATIONS .................................................................. 5
1.8 COMPUTER SOFTWARE ................................................................................................... 5
1.9 SERVICEABILITY ............................................................................................................... 5
1.9.1 Story Drift Limitation .............................................................................................. 6
1.9.2 Expansion joints ..................................................................................................... 6
1.10 OUTLINE SPECIFICATIONS ...................................................................................... 7
1.10.1 Reinforced Concrete ............................................................................................. 7
1.10.2 Structural Steel....................................................................................................... 8
1.10.3 Pre-stressing Concrete ......................................................................................... 9
1.10.4 Concrete Masonry ................................................................................................. 9
1.11 FIRE PROTECTION ................................................................................................... 11
1.11.1 Steel structures .................................................................................................... 11
1.11.2 Concrete Structures ............................................................................................ 11
1.12 WATERPROOFING SYSTEM .................................................................................. 12
1.13 EXPANSION AND CONSTRUCTION JOINTS ...................................................... 12
1.14 STRUCTURAL DESIGN STANDARD ..................................................................... 12
1.15 STRUCTURAL SYSTEM ........................................................................................... 13
1.16 DESIGN PROCEDURE ............................................................................................. 14
1.17 STRUCTURAL MODELING AND DESIGN............................................................. 14
Design Criteria
Page-1
1
STRUCTURAL DESIGN CRITERIA
1.1
CODES, STANDARDS AND PUBLICATIONS
•
•
•
•
•
•
•
•
•
•
•
•
1.2
1.2.1
Saudi Building Code (Structural – Loading and Forces 301)
Saudi Building Code (Structural – Concrete Structures 304)
Saudi Building Code (Structural – Steel Structures 306)
American Concrete Institute (ACI 318M-11).
International Building Code (IBC-2012)
American Society for Civil Engineers (ASCE 7-10).
American society for testing and materials (ASTM)
Saudi Arabian standard Organization (SASO).
Pre-cast Concrete Institute (PCI).
American Institute of Steel Construction (AISC), 14th Edition.
ACI Detailing Manual-2004
Notes on ACI 318, Building Code Requirements for Reinforced Concrete with Design
Applications, Portland cement Association, (PCA)
Loads
Dead Loads
Blinding concrete
Lightweight concrete
Reinforced concrete
Mortar
Marble
Granite
Steel
Sand or gravel (wet)
Asphalt
Masonry concrete lightweight
Masonry concrete medium weight
False ceiling
Hanging load (mech., elect. etc.)
Flooring (Finishes)
Light Partitions
Partitions (Brickwork 150mm)
Partitions (Brickwork 200mm)
1.2.2
23.0
15.0
24.0
20.5
27.0
26.0
77.0
19.0
22.6
16.0
19.5
0.30
0.20
2.00
1.50
3.35
4.30
kN/m³
kN/m³
kN/m³
kN/m³
kN/m³
kN/m³
kN/m³
kN/m³
kN/m³
kN/m³
kN/m³
kN/m2
kN/m2
kN/m2
kN/m2
kN/m2
kN/m2
2.00
1.00
4.80
4.80
4.80
4.80
7.50
2.50
2.00
4.80
4.80
4.80
kN/m2
kN/m2
kN/m2
kN/m2
kN/m2
kN/m2
kN/m2
kN/ m2
kN/ m2
kN/m2
kN/m2
kN/m2
Live Loads
Accessible roof
Inaccessible roof
Public halls & assembly areas
Corridors, hallways, passages, Etc.
Stairs & balconies
Control Room
Mechanical or electrical rooms
Administration buildings (Offices)
Schools (Classes)
Commercial centers (Showrooms)
Garage area (passenger car)
Showrooms
Design Criteria
Page-2
1.3
Seismic Loads
All structures and components will be designed in accordance with the ACSE 7-10
Seismic Categories, site seismic parameters as per SBC 301, an importance factors of (1.00,
1.25, 1.50) will be used for buildings according to risk category.
Region
SBC Seismic Factors
Ss %
S1%
0.8
0.2
RIYADH
Adjustment factor on approximate time period will be used
T= Ta cu <or= computed fundamental period where:
SD1
>0.48
0.38
0.28
0.158
<0.18
1.4
CU
1.4
1.4
1.5
1.6
1.7
Wind Loads
Wind loads will be as per ASCE 7-10 using following formula
qz = Design wind pressure = 0.613 Kz Kzt Kd V² (N/m²)
a.
V
= basic ultimate wind velocity
b.
Kz = Velocity pressure exposure coefficient Table 27.3-1
c.
Kzt = Topographical Factor = 1.0
d.
Kd = Wind directionality factor Table 26.6-1
e.
Exposure Category = C
Basic 3 second guest wind speed as per SBC-301 figure 6.4-1 is 166 Km/h , scaled to the
ultimate wind speeds based on risk category will be as per the following factors
Scale Factor
Category
1.18
1.27
1.36
risk category I
risk category II
risk category III and IV
1.5
TEMPRETURE VARIATIONS
+/-25 degree C. (to be checked with the site location and Saudi standards).
Design Criteria
Page-3
1.6
GEOTECHNICAL
DETAILED
DESIGNPARAMETERS
DESIGN
REQUIRMENT
and
SOIL
1- The geotechnical investigation will be carried out according to subsurface to
investigation specifications.
2-
A plan for the investigated site showing the location of the proposed buildings and the
locations of suggested boreholes and trail pits with their depths and coordinates should
be submitted to Development project Canter for review and approval prior to execution.
3- Geotechnical investigation and report giving a full description of subsurface conditions
include geology of the site, borehole logs and classifications of soils and rocks and
results of in situ and laboratory testing together with recommendation for foundation
design and construction.
4- A geological description of the investigated area including collared geological map
showing geological features for the investigated site should be implemented in the
submitted report.
5-
Adequate geological investigation for each structure to the Owner Representative’s
satisfaction that would enable the complete and adequate characterization of the
geotechnical conditions and define the engineering properties for all subsurface layers
at the location of each structure as well as any adjacent location that may affect the
Structure.
6-
Calculations for safe bearing capacity satisfying stability and serviceability requirements
according to international codes and norms for each building.
7-
Pavement deign according to international codes and norms.
8- Protection measures for foundations against the soil/rock chemical aggressiveness as
determined by adequate chemical analysis for soils, rocks and groundwater to the owner
Representative’s satisfaction.
9- The documents in the paragraph above apply to Geotechnical works as well.
10- Any other documents needed for the proper design and execution of the project.
11- The lateral pressure, coefficients, allowable soil bearing capacities, angles of internal
friction and all other parameters relevant to the structural design will be taken from the
Soil Investigation Report.
12- Depth of foundation shall be at least 1 meter below the existing grade Unless otherwise
specified in the soil report. The allowable bearing capacity shall be as per size and
shape of the footing as indicated in the soil report.
Design Criteria
Page-4
1.7
1.7.1
LOAD COMBINATIONS (As per ACSE 7-10 Chapter 2)
FACTORES LOAD COMBINATIONS
U
U
U
U
U
U
U
U
U
1.7.2
1.8
=
=
=
=
=
=
=
=
=
1.4D
1.4D + 1.7L
1.2D + 1.6L +0.5 Lr
1.2D + 1.6Lr +L
1.2D + 1.6Lr +0.5W
1.2D + 1.0L +0.5Lr ± 1.0W
1.2D ± 1.0E + 1.0L
0.9D ± 1.0W
0.9D ± 1.0E
(9-1)
(SBC)
(9-2)
(9-3a)
(9-3b)
(9-4)
(9-5)
(9-6)
(9-7)
WORKING LOAD COMBINATIONS
U=D
U=D+L
U = D + Lr
U = D + 0.75 L + 0.75Lr
U = D ± (0.6 W or 0.7E)
U = D + 0.75L+ 0.75Lr ± 0.45W
U = D + 0.75L ± 0.525E
U = 0.6 D ± 0.6W
U = 0.6 D ± 0.7E
Computer Software
•
STAAD ORO
1.9
Serviceability
The maximum permissible computed deflection will be computed in according with ACI
318, table 9.5(b)
Design Criteria
Page-5
1.9.1
Story Drift Limitation
For seismic load, story elastic drift limitation shall comply with ASCE 7-10, Table 12.121.
For Seismic load:
Amplified drift = (Cd x\I) where x: deflection determined by an elastic analysis.
Period for computing drift will be based on computed fundamental period of the structure.
For wind load:
Drift limit will be as per the followings:
H/500 For concrete and steel buildings
H/200 For pre engineering metal buildings
1.9.2
Expansion joints
Expansion joints will be provided for concrete structures with maximum spacing of
60m, otherwise temperature effect will be included in analysis.
Expansion joints will be provided for steel structures with maximum spacing of 90m,
otherwise temperature effect will be included in analysis.
Design Criteria
Page-6
1.10 OUTLINE SPECIFICATIONS
1.10.1 Reinforced Concrete
A- Concrete
All Reinforced Concrete work shall conform to ACI 318m-11 specifications. All concrete
will be hard rock, minimum cement content is 400 Kg/m³, slump is not more than 100
mm and will have the following minimum compressive cylinder strength at 28 days:
Concrete Class
Design f’c (MPa)
Location and type of construction
A
50
All pre-cast concrete structures
B
35
All cast in place reinforced
concrete.
C
20
Unreinforced concrete & slab on
grade
B- Cement Type
A-For all structure above ground level, Portland cement type (I) shall be used.
B-For all structure in contact with earth, cement type shall be as per recommendations of
geotechnical report.
C-Sulfate resistant cement type V for blinding concrete.
C-Reinforcing Steel
1- All reinforcement shall be grade 60 (420 MPa) deformed bars conforming to the
requirements of ASTM A615 and meet bend requirement of ASTM A617.
2-
Design Criteria
Welded wire fabric - conforming to ASTM A185.
Page-7
1.10.2 Structural Steel
A- Primary Members:
Primary Structural Members include rigid frames, plates, beams and columns as
follows:
All section shall be of rolled steel forming process shall conform
to ASTM A-607 (Grade50) or equivalent
fy = 345 MPa
Members fabricated from hot rolled structural shape shall
Conform to ASTM A-36 (Grade 36) or equivalent
fy = 250 MPa
B- Connections:
1- All Field connections shall be bolted (unless otherwise noted) and as follows:
All bolted connections shall be furnished with high strength bolts conforming to
ASTM A-325, and A490M type 1 if required.
2- All Shop connections shall be welded, and welding shall be in accordance with
applicable sections, relating to design requirements and allowable stresses, of
the latest editions of the American welding society- AWS - (Structural Welding
Code).
C-Steel columns:
- Columns with end connection plate shall conform to ASTM A913 having a minimum
yield stress 460 N/mm2.
- Anchor bolts shall conform to ASTM A449.
D-Plate and hot rolled sections
Structural steel Plate and hot rolled sections shall conform to ASTM A572 grade 50,
with minimum yield stress of 345 N/mm2.
E-Cold –framed structural Steel Tubing
Shall conform to ASTM A500; grade C. having a minimum yield stress of 345 N/mm2
or equal.
F-Hot Rolled steel hollow circular sections
Shall conform to ASTM A618; grade III, having a minimum yield stress of 345 N/mm2
or equal.
G-Cold rolled steel Z and C sections
shall conform to ASTM A653 grade HSLAS,type A, grade 50 (340) and ASTM
A924/A924M,having a minimum yield stress 345 or equal, and shall be galvanized
in accordance with ASTM A525 to give life to first maintenance with coating class of
G-90.
H-Anchor Bolts
Shall conform to ASTM A572M, Grade 50.
I-High strength Bolts, Nuts and Washers.
shall conform to ASTM A490M type 1.
J-Heated stud-Type Shear Connectors
Design Criteria
Page-8
shall conform to ASTM AWS D1.1 type B, minimum yield strength 345 N/mm2 at
0.2% offset, made from steel to ASTM A108, with mechanical properties to ASTM
A370.
K-Welding Materials
Shall conform to ASTM AWS code and Filler Metal Specifications. Select materials
that are suitable for use with types of steel to be jointed. Unless otherwise indicated,
connections are design for:
-
Metal –Arc welding Electrodes: shall conform to E70XX series of the specification
for Mild Steel Covered Arc-Welding Electrodes, AWS A5.1, or the specification for
Low-Alloy Steel Covered Arc-welding Electrodes, AWS A5.5.
-
Bare Electrodes and Granular Flux used in the submerged-arc process shall
conform to F7 X-EXXX AWS flux classifications of the specification for Base Mild
Steel Electrodes and Fluxes for submerged Arc Welding , AWS A5.17,or A5.23 or
the of AISC “ Specification for the design , Fabrication and Erection of Structural
steel for Buildings”.
L-Space Frames
Witch consists of steel tubes and nodes, gusseted connections are not
Acceptable, and shall comply with the latest version of AISC.
M-Coating
Shall Comply with ASTM A27.
N-Non Shrinkage Grout
Shall have a minimum compressive strength of 60 MPa and complying with
ASTM C109/109M.
1.10.3 Pre-stressing Concrete
The concrete shall have a 28 days cylindrical compressive strength of 50MPa.
A-Cement
Ordinary Portland cement shall conform to “specification for Portland cement”, ASTM
C150 Type I.
B-Reinforcement
All reinforcement shall be deformed high tensile steel having minimum yield strength
FY=420 N/mm2 and shall conform to ASTM A615 and meet the requirement of
ASTM A617.
C-Pre-stressing Strands
Pre-stressing strands shall be low relaxation seven-wire grade 250 ksi minimum
ultimate stress.
1.10.4 Concrete Masonry
1-
Concrete masonry units shall be Type I, Grade N with minimum compressive
strength at 28 days of f’m= 13.8 MPa. Mortar shall be “Type N” for interior walls
or “Type S” for exterior walls. Grout shall have a minimum compressive strength
at 28 days f’g = 13.8 MPa.
2-
Fire rating for concrete masonry units including 15 mm cement plaster facing on
both sides shall be as follows:
Design Criteria
Page-9
i.
100 mm hollow blocks
1:00 hrs.
ii.
150 mm hollow blocks
1:30 hrs.
iii.
200 mm hollow blocks
3:00hrs.
iv.
100 mm solid blocks
2:00hrs.
v.
150 mm solid blocks
4:00hrs.
Design Criteria
Page-10
1.11 FIRE PROTECTION
1.11.1 Steel structures
Lightweight concrete decks shall be a adopted where applicable for its high fire protection
characteristics that can satisfy the required fire endurance, within a limited construction
depth, and without including more loads on the supporting structural Skelton.
Item
Fire protection materials
Fire endurance
(hrs)
Cladded
Exposed
Supporting Floor
2
Sprayed on Fire
Intumescent Paint
Steel Floor Beams
2
Steel Truss
2
Deck Slab
2
Sprayed on Fire
Proofing
Intumescent Paint
Intumescent Paint
Light weight Concrete
Deck
Light weight Concrete
Deck
- For the work shop and were house, the cementations material shall be used for the covering,
if it is compatible with all of ASTM requirement for testing.
1.11.2 Concrete Structures
Concrete cover and minimum section dimensions are chosen to satisfy the fire
endurance requirement of at- least two hours as the following table:
Item
Sub-item
Fire Endurance
(Hours)
Minimum concrete
cover reinforcement
(mm)
Reinforced
concrete
2
40
Pre-stressed
concrete
2
50
Reinforced
concrete
2
25
Pre-stressed
concrete
2
40
Columns
Reinforced
concrete
2
40
Walls
Reinforced
concrete
2
25
Beams
Slabs
Design Criteria
Page-11
1.12 WATERPROOFING SYSTEM
1.
Under Plain Concrete
300 Micron Poly Ethylene sheets below the area of plain concrete
and its sides, including the top of the plain concrete beside reinforced
concrete foundation.
2
Reinforced concrete Foundation sides, Buried columns &Buried walls :( in
of no ground water table)
Two coating of Bituminous Emulsion Paint.
3.
Water proofing membrane sheet under and around water tanks and in
case of ground water table existing:
A-Two layers of water proofing membrane of thickness 4 mm, self-adhesive type SBS,
with minimum elongation of 200%.
B-18 mm Protection Board covering the Poly Ethylene Sheets before backfilling.
4.
Wet area’s water proofing membrane:
Two layers of water proofing membrane sheets minimum thickness 4mm.
1.13 EXPANSION AND CONSTRUCTION JOINTS
Expansion joint shall be provided wherever is needed, whereas construction joint
shall be provided where necessary.
1.14 STRUCTURAL DESIGN STANDARD
Structural Calculations Guidelines
A
B
C
D
E
Structural calculations shall be performed using currently accepted methods of
analysis and design.
Structural analysis and design shall incorporate all gravity loads, lateral
loads/forces and static equivalent forces imposed upon the structure, including
design live loads. Lateral forces consist of loadings from wind, earthquake, sway,
impact, and lateral soil pressures. Static equivalent loads shall include earthquake
loading.
Loading combinations shall follow current acceptable standards.
Structural calculations shall be performed in a neatly organized and orderly
fashion. All pages shall be fully titled and sequentially numbered and all volumes
appropriately indexed. References to engineering analysis and design books shall
be noted where occurring.
Structural calculations performed by computer shall be organized, indexed and
sufficiently identified on input forms and output data such that all data can be
collated. Programs descriptions shall include the principles of analysis used in the
programs. Programs used shall be sufficiently documented that input data and
output data is readily understandable.
Design Criteria
Page-12
1.15
STRUCTURAL SYSTEM
i.
Structural Framing
Structural elements e.g. slabs, beams columns and footings are combined in various
ways to create structural systems for buildings and other construction space. For the
selection of a suitable framing system for a building, the determining factors are:
-
Appearance, functional & aesthetic requirements.
-
Limitations on the size (Depth –width) of structural members as imposed by
architectural design and practical constraints on the basis of structural
considerations.
-
Clear spans and height are required.
-
Loads, including special loads.
-
Availability of materials, skilled labor and construction equipment.
-
Integration of structure with respect to architectural details, mechanical
equipment, occupancy requirements etc.
-
Economy, not merely in structural frame but also the overall economy in the
finished structure.
Considering above factors the structural system adopted for this project shall consist
of cast-in-situ Moment Resisting Frame a combination of reinforced concrete floor
beam and columns to resist the gravity and lateral loads.
The sizes of columns shall be so arranged to suit the structural design and
architectural requirements. The grade beam shall be designed to support the block
wall and to retain the level difference between building and outside open
yard/walkway.
Floor Beams and Slabs
Selection of proper floor and roof system will be based on Spans, loads, deflection
limitations, etc.
-
Acoustical and thermal insulating properties.
Framing details; attachment to supports, support of hung ceilings, ducts, light
fixtures, piping, etc.
- Structural system for floors and roof used in this project is as following: Flat slab with thickness 250-350 mm with / or without drop panel can be used as
suitable for structural design and architectural requirements. The thickness of flat
slab should satisfy the short and long term deflection.
Dropped beam should be avoided as far as possible, but can be used for peripheries
dropped beams.
For halls area steel vierendeel truss is proposed to carrying the planted steel
columns may be suitable for this area. The vierendeel truss system should be
improved to carry all loads and vibrations of mechanical loads equipment and roof
area, and span of panel can be controlled the Bending moment distributions in
Vierendeel girders with variable Adjusted distances between posts to generate
uniform bending moment distributions.
Design Criteria
Page-13
1.16
1.17
DESIGN PROCEDURE
▪
The buildings will be made of reinforced concrete beam column frames and flat
slab or solid slab system depending upon the spans configuration. The primary
material for construction for the building is reinforced concrete.
▪
The grade beams and grade slabs will be provided at the ground level for
distribution of loads to the foundations and natural ground respectively.
▪
Building foundations will be designed as per recommendations of soil
investigation report. The depth and sizes of the foundations will be finalized
based on the structure reactions and the results of soil investigations.
▪
All applicable codes and specifications mentioned in the design criteria will be
followed.
▪
The building structures will be analyzed through computer software such as
ETABS, SAFE, and RAM, Limcon for steel structure connections.
STRUCTURAL MODELING AND DESIGN
▪
The structure should be modeled in 3D, beams and columns are represented
as frame elements, one-way hollow block slabs are representing as shell
elements (membrane type) while two way slabs and solid slabs are
representing as shell elements (shell type).
▪
Design calculations for all structural components were prepared as per
relevant codes and specifications as listed in the design criteria.
Design Criteria
Page-14
▪ Appendix 1 – Saudi Wind Map
▪ REFERENCE WIND SPEED
Design Criteria
Page-15
▪ Appendix 2 – Saudi Seismic Maps
Design Criteria
▪
(attachment # 2)
▪
SEISMIC
▪
Figure 9.4.1(o): Maximum
Motion for the Kingdom
Acceleration (S1 in %g)
Site
Class
DESIGN
CRITERIA
Considered Earthquake Ground
of 1 SEC Spectral Response
(5 Percent of Critical Damping),
B.
(Region
5)
Page-16
▪
Design Criteria
Figure 9.4.1(g): Maximum Considered Earthquake Ground
Motion for the Kingdom of 0.2 SEC Spectral Response
Acceleration (Ss in%g) (5 Percent of Critical Damping), Site
Class B.(Region 5)
Page-17