1. An-Najah National University
Faculty of Engineering
Civil Engineering Department
Terra Santa School Structural Design and Analysis
Prepared By:
Bara Shawahna Khaled Malhis Nadeem AL-Masri
Supervised By : Dr. Mahmud Dwaikat
2. OUTLINE
ο± Introduction & general description of the project
ο± 3D modeling
ο± Shear walls design
ο± Design of columns
ο± Design of beams
ο± Slabs design
ο± Foundation design
3. INTRODUCTION
ο Our Graduation project is the design of a school in Jericho
named as Terra Santa School. This school was designed by
Al-Diyar Consultant and we will check on their design.
ο The school consists of three floors with total plan area of
(3866.5m2).
5. ο SAP 2000 program will be used as main analysis tool.
ο ACI 318-08 for design.
ο Live loads are taken from ASCE 7 -05 code.
ο UBC 97 for seismic design.
Methodology
6. MATERIALS USED IN THE PROJECT:
ο Reinforced concrete
ο The unit weight of concrete (πΎ) = 25 kN/m3.
ο The required compressive strength after 28 days
ο For slabs & beams fc is 25 MPa.
ο For Columns ,shear walls & footing fc is 30 MPa.
ο The yield steel bars required Fy = 420 MPa.
7. STRUCTURAL SYSTEMS
ο For each block we chose the following floor system:
1. Block A ( one way ribs slab )
2. Block B ( one way ribs slab )
3. Block C ( two way ribs slab )
Blocks A & B.
Itβs very clear to see that block A , B has a uniform grid for columns with clear
path of loading (one-way), therefore, we took the architectural layout for the
columns. Ribbed slabs are known for their economic efficiency. The thickness
calculation follows the ACI-318 code
Block C.
Block C has a different shape and dimensions and according to ACI β code
requirements the slab should be designed as two-way ribbed slab for
economic and deflection requirements. This is because the spans of each
panel in Block C have approximately equal lengths.
8.
9. LOADS
Dead load:
ο Own weight for one way slabs = 3.54 kN/m2 .
ο Own weight for two way slabs = 4.86 kN/m2 .
ο Super imposed load = 3 kN/m2 .
Live load:
ο for all the class room = 2 KN/m2 .
ο for corridors = 5 KN/m2.
10. ANALYSIS AND DESIGN AGAINST SEISMIC
LOADS
ο We will design the seismic load by using SAP2000. Several methods is
used in SAP for seismic which is:
ο Dynamic analysis:
1. Response spectrum.
2. Time history.
ο Equivalent static force
Equivalent static method will be used for comparison [Block A only] and
as a cross-check on the results of response spectrum analysis. Because
response spectrum is more realistic and covers the modal shapes of the
building, we will use it as a main tool for seismic design.
11. ο The seismic force effect on the structure can be translated to equivalent
lateral force at the base of the structure and then this force will be
distributed to the different stories and then to the vertical structural
elements (frames and/ or shear walls).
ο This method is best applied to Regular Structure only.
12. DESIGN FOR EARTHQUAKE BY EQUIVALENT LATERAL FORCE
METHOD (STATIC METHOD) FOR BLOCK A
ο We will use the UBC97 method for analysis, because of available data and factors in
our region.
ο The total design base shear in a given direction shall be determined from the
following formula:
ο Where
π =
πΆπ£ πΌ
π π
π€
1. Z= seismic zone factor.
2. I= importance factor.
3. R= Response Modification Factor
4. CV= velocity seismic coefficient.
5. W= the total dead load.
16. RESPONSE MODIFICATION FACTOR βRβ TABLE
The overall system is dual system
R for building between (4.2-6)
=5.6
17. T CALCULATION
ο π = πΆπ‘(βπ)
3
4
ο Hn= height of structure in meters = 15m
ο Ct = factor for this case =0.0488
ο T= is the basic natural period of a simple one degree of freedom
system which is the time required to complete one whole cycle during
dynamic loading.
ο And after calculation T=0.3719 sec, T from sap for block A =0.25 sec.
Difference can be due to presence of shear walls that increase the
stiffness of the building block.
18. ο Then calculate π =
0.54π1.25
5.5π0.3719
Γ w = 0.33W
ο ππππ = 0.11 π πΆπ π πΌ π π
ο Vmin. = 0.11X0.36 X1.25X w=0.0396W
ο Vmax=
2.5ππΆπππΌ
π
π ο¨ 0.2W
ο Vmax= 0.20 W use it because it Vcalculated>Vmax
ο For block A the weigh is = 12206 kN
ο V=0.20 X12206 =2441.2kN
ο From SAP Vtotal equivalent static force equal =2125kN.
ο From SAP Vtotal Response spectrum equal =1950kN.
19. RESPONSE SPECTRUM METHOD
ο We use sap to design and analyze the project the design response
spectrum is shown in
20. ο We find CA=0.36,CV=0.54
Then we have this curve
21. ο Then we should define a load cases in the X-direction, Y-direction, Z-
direction
ο When we define X-direction for example:
ο We scale factor is for X direction =
ππΌ
π
=
9.81π1.25
5.6
= 2.227
ο And 33% of it for to the other direction Y = 0.33X2.227=0.7329 ( as per
UBC97 and ASCE requirements)
.
26. EQUILIBRIUM CHECK
FOR BLOCK A
ο Dead load:
1. Slab dead load = area X slab own weight per square meter =1185.84
X 3.54=4136.4 kN
2. Shear wall load = walls volume X concrete weight per volume = 28.7 X0.3
X15 X 25=3288.75 kN
3. Columns dead load = column volume X concrete weight per volume =
30 X 15 X0.4 X 0.4 X 25=1800 kN
4. Beams dead load = beams volume X concrete weight per volume =
3691.4 kN
5. Total dead load = 12917.6 kN
6. Total dead load form SAP = 12956.699
7. % Error = 0.3% which is acceptable
27. ο Live load:
Structure area X live load per square meter =1185.84 X 5 =5929.2 kN
Live load from SAP = 5929.2 kN
% Error = 0
ο Superimposed dead load:
Structure area X superimposed load per square meter = 1185.84 X 4.5
= 5336.28 kN
Superimposed load from SAP = 5336.2 kN
% Error = 0
28. MOMENT EQUILIBRIUM CHECK
ο We take block A as example to do this check. In this check we take the
moment from 3D modeling and find the weight and then comparing it
with the hand calculated weight
ο Moment resulted from dead load in block A in beam B1 is:
29. ο Calculating the moment =
39+44.75
2
+ 28.9 = 70.775 ππ. π
ο
π€Γπ2
8
= π ,
70.775Γ8
6.82 = 12.244
ππ
π
ο To convert it to kilo newton per square meter divide it over tributary
area which equal 3 meter
ο W = 4.08 kN/m2
ο Calculated dead load = 3.54 kN/m2.
ο % of error =
4.08β3.54
3.54
Γ 100% = 15%
ο Check for sway and non-sway:
ο
βππ’ π π·ππππππ‘πππ
βππ’ π πππππ‘β ππ ππππ’ππ
< 0.05
ο
361300
6068820
= 0.059
ο Its acceptable value. ο¨ non-sway
30. DESIGN OF SHEAR WALLS
ο Design B2 in block B
ο axial force value Pu < 0.1 Ag fc
ο The maximum moment in the wall is 6824 kN.m
ο Assume singly reinforced section with reinforcement at d= 0.8h:
ο π =
0.85 ππ
ππ¦
1 β 1 β
2π
0.85α΄ππ2ππ
ο =
0.85Γ30
420
1 β 1 β
2Γ6824Γ106
0.85Γ0.9Γ300Γ45002Γ30
= 3 Γ 10β3
ο π΄π = 0.003 Γ 1000 Γ 300 =
900 ππ2
π
5β 16/π
ο π
π =
1
6
Γ ππ
β²
Γ ππ€ Γ π=0.1666π₯ 30π₯300π₯4500/1000 = 1233ππ
ο Vu from sap =756 kN
ο π
π =
ππ’
β
, π€βπππ β = 0.75
ο π
π =
756
0.75
= 1008 ππ
ο π
π > π
π π’π π ππππππ’π π π‘πππ =(1 β 12/20ππ)
32. DESIGN OF THE COLUMNS AGAINST SEISMIC
LOAD
ο Columns in Category C4(110X50)cm
ο We take the moment value from 3D βmodal of
π1
π2
we have
π1
π2
=
312
298
= 1.04.
ο
ο For the effective length factor (K) we take the building non sway so we
take k from Οmajor= Ο a=
πΈππΌπ/ππ
πΈππΌπ/ππ
= 12.4 , Ο b=50 and Ο minor=
πΈππΌπ/ππ
πΈππΌπ/ππ
=
11.99 and Ο b=50the which is between equal 0.98 take it 1.
ο
πΎπΏ
π
= 34 β 12
π1
π2
ο Check slenderness limit
1π3000
0.3 β
< 34 β 12
312
298
ο non-slender column
ο Using strength calculation, Pu<π«Pn for the same column, we got Ag =
5500000mm2. So the other dimension is5500000/500= 110mm. This
dimension should be larger or equal the least dimension so let it equal
500mm, so we took it equal to 500 mm
ο The dimension of column 110X50 cm so Ag= 5500cm2
ο Strength calculations for this column are done as follows:
33. ο From SAP2000 and 3D-model we take Pu=8287 and it equal π«Pn then
we go to the interaction diagram and take the steel ratio value= 0.012
ο π«Pn/bh=15 =2.15 ksi
ο Β₯=h-2couver/h = 0.9
ο Mu/bh2=1.44 = 0.2 ksi
34. π
π =
1
6
Γ ππ
β²
Γ ππ€ Γ π =β π
π =
1
6
Γ 30 Γ 1100 Γ 460/1000 = 461.9 ππ
π
π =
π
π’
β
, π€βπππ β = 0.75
π
π =
88
0.75
= 117 ππ
From SAP2000 the shear value on the column is equal 117 kN <463.9 itβs Ok
Since the column is not subjected to shear, we use minimum steel for shear reinforcement so as to hold vertical bars and
confine concrete.
The stirrup spacing must be the minimum of the following
β’48 ds (diameter of stirrups)β¦β¦β¦..From code ACI 318-08
β’16 db(diameter of bar) )β¦β¦β¦..From code ACI 318-08
β’Least diminution of the section )β¦β¦β¦..From code ACI 318-08
β’Not more than d/2β¦β¦..From ACI 315-99
Therefore, use α΄10
β’48 * 10 = 480 mm
β’16 * 20= 320 mm
β’500 mm
β’460/2= 230 mm
Therefore use 4α΄10/150mm for stirrups along the column
38. FOR BEAM B1 AT BLOCK A UNDER SEISMIC LOAD
(50X35 CM)
39. ο ππππ = πππ₯
1.4
ππ¦
,
0.25β ππ
ππ¦
= πππ₯
0.00333,
0.00297
ο
ο π’π π ππππ = 0.00333
ο For left span
ο Negative moment need 1284 mm2 (5π«20 mm).
ο For positive moment need 945 mm2 (4π«18 mm).
ο
ο For the right span
ο Use (5π«20 mm) for top steel
ο And (4π«18 mm) for bottom steel
41. ο Near the column face
ο
π΄π£
π
= 0.774
ο π =
157
0.774
= 200 ππ
ο Use 1 π« 10 /100 mm
ο At the middle
ο
π΄π£
π
= 0.292
ο S=500> S max
ο So use S max 230 mm
ο Use 1 π« 10 /150 mm
ο Right span
ο
π΄π£
π
= 0.596
ο S= 263 mm > S max
ο Use 1 π« 10 /100mm
42.
43. SLAB DESIGN
ο The maximum span length is about 2.7m as shown in Block A,B Map,
and therefore the thickness of the slab (assumed one-way ribbed)
according to the table will be L /18.5 =15 cm and we used 20 cm for
block A& B(S1).
44. ο The maximum span length is about 7.55m as shown in Block C Map,
and therefore the thickness of the slab two-way ribbed according to the
table will be Ln /30 =25.1 cm and we used 30 cm.
45. ο For Slab S1 at block A (20 cm):
ο Slab S1 is one way ribbed slab with 9 spans 2.7m for each.
ο Dead and super imposed load = 8.04 kN/m2
ο Live load= 5kN/m2 due to corridor live load.
ο All π value is less than ππππ so use ππππ for design.
ο Asmin = ππππ X bw X d= 0.0033X120X180=72mm .Used 2αΆ²10.(As bottom steel
46. ο Top rib steel
All π value is less than ππππ so use ππππ for design.
ο Asmin = ππππ X bw X d= 0.0033X120X180=72mm .Used 2αΆ²10.
ο For Shrinkage net steel
ο Asmin = ππππ X b X d= 0.0018X1000X60=108mm2 Used 2αΆ²8
47. DESIGN FOR TWO WAY RIBBED SLAB IN BLOCK C
m11 (x-direction moment)
48. ο For left span the positive moment is
ο Mu =
86.4
(18.7β15.8)
= 29.8 ππ. π
ο π =
0.85 ππ
ππ¦
1 β 1 β
2ππ’
0.85α΄ππ2ππ
= 0.0092
ο As = π X bw X d= 0.0092X120X280=310 mm
ο Use 2π«16
ο For right span the positive moment is
ο Mu =
30
16.5β15.5
= 30 ππ. π
ο π =
0.85 ππ
ππ¦
1 β 1 β
2ππ’
0.85α΄ππ2ππ
= 0.00928
ο As = π X bw X d= 0.00928 X 120 X280= 310 mm
ο Use 2β 16
49. ο Design for negative moment (A-B section in x-direction)
Negative moment at the middle near the beam face.
ο Mu =
78
(16β14)
= 39 ππ. π
ο π =
0.85 ππ
ππ¦
1 β 1 β
2ππ’
0.85α΄ππ2ππ
= 0.0125
ο As = π X bw X d = 0.0125 X 120 X 280= 420 mm
ο Use 2π«20 (as top steel)
Negative moment at right edge
ο Mu =
60
(18β16)
= 30 ππ. π
ο π =
0.85 ππ
ππ¦
1 β 1 β
2ππ’
0.85α΄ππ2ππ
= 0.00928
ο As = π X bw X d = 0.00928 X 120 X 280= 312 mm
ο Use 2π«16 for both left and right edge (as top steel).
51. Design of F1 for C1
ο Pservice = 1200kN.
ο Pultimate=1500kN.
ο Bearing capacity= 250 kN/m2
ο Area of footing =
ππ’ππ£πππ ππππ
πππππππ πππππππ‘π¦
=
1200
250
= 4.8 m2
ο So we will use B= 2.2, L= 2.2
ο Footing long side (l)=
πΏβπΏ ππππ’ππ
2
=
2.2β0.4
2
=0.9m
58. the maximum moment is 238kN.m. in x-axis
π =
0.85 ππ
ππ¦
1 β 1 β
2π
0.85α΄ππ2ππ
= 0.1%
π < ππππ
Use π = 0.0018
As = 0.0018Γ1000Γ800=1440 mm/m
the maximum moment is 414 kN.m in y-axis
T hen calculate π =
0.85 ππ
ππ¦
1 β 1 β
2π
0.85α΄ππ2ππ
= 0.173%
π < ππππ
Use π = 0.0018
As = 0.0018Γ1000Γ800=1440 mm/m
For shrinkage steel As = 0.5Γ0.0018Γ1000Γ800 =720 mm/m (5 π«14 mm / m).