Draft No. 1
ACI 314 Task Group B/C
Preliminary Design of a 20-story Reinforced Concrete Building
By
Mike Mota, P.E. Chair Task B-C Preliminary Design and Economical Impact Member of ACI and Secretary of Committee 314 Atlantic Regional Manager CRSI Jim Lai, S.E. (Retired)
March 19, 2008
Page 1 of 46
Draft No. 1
ACI 314 Task Group B/C TABLE OF CONTENTS
1.
Building description………………………………………………………………..………..3 1.1 Material……………………………………………………………………………..3 1.2 Design loading………………………………………………………………………3 1.3 Story weight………………………………………………………………. ………..3 1.4 Governing codes…………………………………………………………………….3
2.
Outline of preliminary design procedure:……………………………………………………6 2.1 Loading:……………………………………………………………………………..6 2.1.1 Develop seismic loading based on ASCE7-05 Chapter 11 and 12……………6 2.1.2 Design of structural wall (shear wall)…………………………………………6 2.1.3 Design of special moment frame………………………………………………6
3.
Lateral Force Analysis:………………………………………………………………………7 3.1 Mapped Spectral Acceleration………………………………………………………7 3.2 Structural System……………………………………………………………………7
4.
Equivalent Lateral Force Procedure:…………………………………………………………8 4.1 Unit Loads …………………………………………………………………………..9 4.2 Seismic Story Shear and Building OTM…………………………………………….9 4.3 Preliminary design of structural wall……………………………………………….10
5.
Moment Frame Design:……………………………………………………………………..21 5.1 Two moment frames in each direction……………………………………………..22 5.2 Seismic Force distribution using Portal Method…………………………………...25 5.3 Based on two cycle moment distribution…………………………………………..25 5.4 Column axial load (Between 3rd and 4th Floor)…………………………………..25
6.
Preliminary Material Quantities for Superstructure only…………………………………....31 6.1 Shear-walls………………………………………………………………………….31 6.2 Columns…………………………………………………………………………….32 6.3 Slabs………………………………………………………………………………...32
7.
Appendix A:
Power-point slides from Atlanta Session…………………………………..34
Page 2 of 46
Draft No. 1
ACI 314 Task Group B/C TABLE OF CONTENTS
1.
Building description………………………………………………………………..………..3 1.1 Material……………………………………………………………………………..3 1.2 Design loading………………………………………………………………………3 1.3 Story weight………………………………………………………………. ………..3 1.4 Governing codes…………………………………………………………………….3
2.
Outline of preliminary design procedure:……………………………………………………6 2.1 Loading:……………………………………………………………………………..6 2.1.1 Develop seismic loading based on ASCE7-05 Chapter 11 and 12……………6 2.1.2 Design of structural wall (shear wall)…………………………………………6 2.1.3 Design of special moment frame………………………………………………6
3.
Lateral Force Analysis:………………………………………………………………………7 3.1 Mapped Spectral Acceleration………………………………………………………7 3.2 Structural System……………………………………………………………………7
4.
Equivalent Lateral Force Procedure:…………………………………………………………8 4.1 Unit Loads …………………………………………………………………………..9 4.2 Seismic Story Shear and Building OTM…………………………………………….9 4.3 Preliminary design of structural wall……………………………………………….10
5.
Moment Frame Design:……………………………………………………………………..21 5.1 Two moment frames in each direction……………………………………………..22 5.2 Seismic Force distribution using Portal Method…………………………………...25 5.3 Based on two cycle moment distribution…………………………………………..25 5.4 Column axial load (Between 3rd and 4th Floor)…………………………………..25
6.
Preliminary Material Quantities for Superstructure only…………………………………....31 6.1 Shear-walls………………………………………………………………………….31 6.2 Columns…………………………………………………………………………….32 6.3 Slabs………………………………………………………………………………...32
7.
Appendix A:
Power-point slides from Atlanta Session…………………………………..34
Page 2 of 46
Draft No. 1
ACI 314 Task Group B/C 1
1. Building Description:
20-story office building in Los Angeles, CA has a dual moment resisting frame system of reinforced concrete structural walls and reinforced concrete moment frames. Typical floor plan and an elevation are shown in Figures 1 and 2. The building is square in plan with five 28-ft bays totaling 142 ft – 3 inches out to out in each direction. Story heights are 23 ft from the first to second floors and 13 feet for the remaining 19 stories; the overall building height is is 270 feet. Typical floor framing consists of 4½ inches thick light weight concrete slabs, 12 x 18½ beams at 9 ft- 4in o.c. and 18 x 24 girders; interior columns are 30 inches square for the full height of the building. Girders at the periphery of the floor are 27 x 36 and columns are 36 inches square for the full height of the building.
A 28 ft x 84 ft x 13 ft high penthouse with equipment loading at the roof level
A small mezzanine floor at the first story
1.1 Material:
Concrete Strength –
f c´ = 4,000 psi above 3 rd floor (light weight 115 pcf) f c´ = 5,000 psi below 3 rd floor (normal weight)
Reinforcement -
f y = 60,000 psi
1.2 Design Loading:
Partition including miscellaneous miscellaneous dead load = 20 psf Floor Live load = 50 psf (reducible based on tributary area)
1.3 Story weight:
Roof = wrf =2800 kips Floor 16–20 wi = 2800 kips Floor 9 – 15 wi = 2850 kips Floor 3 – 8 wi = 2900 kips Floor 2 w2 = 4350 kips Total building weight Σwi = 58,500 kips
1.4 Governing Codes:
IBC -2006 ACI 318-05 ASCE 7 -05
1
This example was originally developed by James S. Lai of Johnson and Nielsen Associates, Structural Engineers, Los Angeles, CA for BSSC trial design and was published in FEMA 140, “Guide to Application of NEHRP Recommended Recommended Provisions Provisions in Earthquake-Resistant Earthquake-Resistant Building Design,” Design,” Building Seismic Seismic Safety Council, Washington, D.C. 1990.
Page 3 of 46
Draft No. 1
ACI 314 Task Group B/C
5 Bays @ 28’ 0” = 140’ 0”
Typical Bay
Stair
Beam Girder
Elevator Opening
Fig. 1 - Typical Floor Plan
Page 4 of 46
5 Bays @ 28’ 0” = 140’ 0”
Draft No. 1
ACI 314 Task Group B/C
Roof 20 19 18 17 16 15 14 13 12 11
19 Stories @ 13’ 0” = 247’ 0”
10 270’ 0” 9 Columns 8 7 6 5 4 3 2 23’ 0” 1
Fig. 2 - Elevation
Page 5 of 46
Draft No. 1
ACI 314 Task Group B/C 2.0 OUTLINE OF PRELIMINARY DESIGN PROCEDURE: 2.1 LOADING 2.1.1 Develop seismic loading based on ASCE7-05 Chapter 11 and 12.
Establish response modification factor R, deflection amplification factor C d and overstrength factor Ω0 Establish mapped maximum considered earthquake spectral response acceleration for short and long periods Ss and Sl from USGS data base Calculate design spectral response acceleration S Ds and SDl Establish a standard response spectrum for design reference Calculate fundamental period T a using (Eq. 12.8-7) Calculate seismic response coefficient, C s Calculate seismic base shear V Calculate vertical distribution of story seismic forces Calculate building overturning Distribute seismic forces to structural walls and building frames accounting for accidental torsion Approximate building deflection (any suggestions without doing computer run?) 2.1.2 Design of structural wall (shear wall)
Obtain seismic base shear for one wall pier from horizontal distribution Calculate required seismic shear strength at lower story Design wall thickness or guess at wall thickness and calculate nominal shear strength base on 8 √f c´ Calculate seismic overturning moment by proportion of building overturning or from story force distribution Calculate gravity loads dead and live with the approximate loading combinations Base on the calculated seismic OTM, obtain the approximate area of tension reinforcement Check for requirement of boundary element based on Section 21.7.6 (ACI 318) Establish P0, P b, M b, Mn to draw an interaction diagram based on φ = 1 Based on Pu/φ and Mu/φ, check that design is within the interaction diagram envelope Check for termination of boundary reinforcement requirement Calculate confinement reinforcement for longitudinal boundary rebar For upper stories, establish shear strength for reduce wall thicknesses and the minimum reinforcement requirements 2.1.3 Design of special moment frame
Obtain seismic base shear for one perimeter frame from horizontal distribution (no less than 25% of total building shear) Distribute story seismic shear to column based on portal method (or other acceptable method) Calculate seismic axial force and moments in end column and first interior column Calculate gravity loads dead and live axial loads Calculate gravity load moments based on approximate coefficients Obtain combined loading combinations for girders and columns For girder design, calculate minimum required flexural strength and reinforcement Calculated required shear strength based on probable moment strength of girder, and design shear reinf. For column (design end column and first interior column), design longitudinal reinforcement such that the column moment strength satisfies equation (21-1.) Calculate probable moment strength of column ends Calculate required shear strength Design transverse confinement reinforcement Check joint shear strength requirement
Page 6 of 46
Draft No. 1
ACI 314 Task Group B/C
3. Lateral Force Analysis (Seismic) Code: ASCE 7-05 and ACI 318-05
Reference ASCE 7-05
3.1 Mapped Spectral Acceleration
11.4.1 Short period
Sa
=
2.25
From USGS data base
One second
S1
=
0.75
From USGS data base
Site Class
D Site Coefficent
11.4.2 Fa
=
1.0
Table 11.4-1
Fv
=
1.5
Table 11.4-2
Maximum Considered Earthquake SMS
=
Fa Ss
=
2.25
(Eq. 11.4-1)
SM1
=
Fv S1
=
1.13
(Eq. 11.4-2) 11.4.4
SDS
=
2SMS/3
=
1.50
(Eq. 11.4-3)
SD1
=
2SM1/3
=
0.75
(Eq. 11.4-4)
Design Response Spectrum
11.4.5 T0
=
0.2 SD1/SDS
=
0.10
sec
Short period transition period
TS
=
SD1/SDS
=
0.50
sec
Long period transition period
TL
=
12.0
For T < T0
Sa
=
For T0 ≤T ≤ TS
Sa
=
SDS
=
For TS ≤T ≤ TL
Sa
=
SD1/T
=
0.563
(Eq. 11.4-6)
Sa MCE
= =
SD1 TL/T2 1.5 DBS
= =
0.845
(Eq. 11.4-7) 11.4.6
I
=
1.0
For T > TL MCE Response Spectrum
Occupancy Category
From USGS data base
SDS[0.4 + 0.6 T/T0] =
(Eq. 11.4-5)
11.5.1 Table 11.5-1
Seismic Design Category
11.6
Based on SDS
D
SDS
≥
0.50
Table 11.6-1
Based on SD1
D
SD1
≥
0.20
Table 11.6-2 12.2
3.2 Structural System
D3
Table 12.2-1
Response Modification Factor
R
=
7.0
Table 12.2-1
System overstrength factor
Ωo
=
2.5
Table 12.2-1
Deflection amplification Factor
Cd
=
5.5
Table 12.2-1
Height Limit
NL
Table 12.2-1
Horizontal Structural Irregularity
None
Table 12.3-1
Vertical Structural Irregularity
None
Table 12.3-2
Redundancy Factor Analysis procedure
ρ
=
1.0
T
<
3.5 Ts
Equivalent Static analysis
Page 7 of 46
12.3.4.2 =
T = fundamental period of structure
I
Importance Factor
Dual System
Default Site Class
11.4.3
Design Spectral Accel parameter
USE:
Remarks
1.75
Table 12.6-1
1.5 x Design response spectrum
Draft No. 1
ACI 314 Task Group B/C
4. Equivalent Lateral Force Procedure
12.8
Building Height
hn
=
Effective Seismic Weight
W
=
270
ft
58,500
Problem statement
kip
Calculation of Seismic Response
12.8.1.1 12.8.1.1
Seismic Reponse Coefficient For T ≤ TL
Cs
=
S DS /[R/I]
Cs
=
SD1 /T[R/I] =
> For S1 ≥ 0.6
Cs
=
0.214
(Eq. 12.8-2)
0.080
(Eq. 12.8-3)
0.01
=
Governs design
(Eq. 12.8-5)
0.5 S1/[R/I] =
(Eq. 12.8-6)
Building Period
12.8.2.1 Period Parameter
Ct
=
Period Parameter
x
=
Approx. Fundamental Period
T=
Seismic Base Shear
Ta
=
Ct hnx
V
=
Cs W
0.02
Table 12.8-2
0.75
Table 12.8-2 =
1.33
sec.
(Eq. 12.8-7)
=
4,705
kip
(Eq. 12.8-1)
Vertical Distribution of Force
12.8.3
Vertical Distribution Factor
Cvx
=
wx hxk / Σwihik
(Eq. 12.8-12)
= For T < 0.5
k
=
k
=
For T ≥ 2.5
k
=
2.5
Story Force
Fx
=
Cvx V
For T =
1.33
1
Horizontal Distribution of Force
Accidental Torsion Amplification of Mta
Interpolate in between
1.2
12.8.4 Vx
=
Mta
=
Ax
=
n i= xΣFi
(Eq. 12.8-13) 5%
12.8.4.2
[δmax /1.2δavg]
2
= Deflection at center of mass Period for computing drift δxe
δx Τ
=
Cd δse/I
=
CuTa
Cu
=
(Eq. 12.8-15) 12.8.6.2 Table 12.8-1
P-Δ Effects
12.8.7 Stability Coefficient
θ
=
Px Δ /[Vx hsx Cd]
(Eq. 12.8-16)
0.5/ (β Cd)
(Eq. 12.8-17)
= θmax
= ≤
0.25
Page 8 of 46
Draft No. 1
ACI 314 Task Group B/C
4.1 Unit Load Typical Floor Finish floor 4½" LW Conc. Slab Ceiling Misc Partition Beams Girders Columns Dead Load* Live Total Load
2 45 7 6 10 20 10 70 50 120
90 40 130
10 110 30 140
100 35 135
* USE same load at roof to allow for equipment wt. 4.2 Seismic Story Shear and Building OTM
Level
k=1.2
wx hxk Σwihi
Seismic Force at Level x
Story Shear Force
OTM
x 103
Cvx
kips
kips
kip-ft
Height to Level x hx
Weight at Level x wx
wx hxk
ft
kips
Roof
270
2,800
2,316
0.099
468
20
257
2,800
2,183
0.094
441
468
6,080
19
244
2,800
2,051
0.088
414
908
17,889
18
231
2,800
1,921
0.082
388
1,323
35,083
17
218
2,800
1,792
0.077
362
1,710
57,319
16
205
2,800
1,664
0.071
336
2,072
84,258
15
192
2,850
1,566
0.067
316
2,408
115,565
14
179
2,850
1,440
0.062
291
2,724
150,983
13
166
2,850
1,315
0.056
266
3,015
190,180
12
153
2,850
1,193
0.051
241
3,281
232,829
11
140
2,850
1,072
0.046
216
3,521
278,607
10
127
2,850
954
0.041
193
3,738
327,200
9
114
2,850
838
0.036
169
3,930
378,296
8
101
2,900
737
0.032
149
4,100
431,590
7
88
2,900
625
0.027
126
4,248
486,820
6
75
2,900
516
0.022
104
4,375
543,690
5
62
2,900
410
0.018
83
4,479
601,913
4
49
2,900
309
0.013
62
4,562
661,214
3
36
2,900
214
0.009
43
4,624
721,327
2
23
4,350
187
0.008
38
1
0
Total
58,500 Seismic base shear
23,304
1.000 V=
Page 9 of 46
4,667
782,002
4,705
890,218
4,705 4705
kips
Draft No. 1
ACI 314 Task Group B/C
28.0 1.25 A
3.00
22.0
3.00
1.25
A 2.5 P1
P2
P3
h 4.25 A-A Plan
Elevation 4.3 Preliminary design of structural wall Dead Load Level
Roof 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1
Note 1 2
P1
P2
Live Load P3
ΣPD
131 147 147 147 147 147 147 147 147 147 147 147 147 147 147 147 147 151 151 227
24 56 56 56 56 56 56 56 56 56 56 62 62 62 62 62 62 66 66 133
65 81 81 81 81 81 81 81 81 81 81 81 81 81 81 81 81 86 86 129
220 284 284 284 284 284 284 284 284 284 284 290 290 290 290 290 290 304 304 489
3,005
1,225
1,666
5,896
P1
220 504 788 1,072 1,356 1,640 1,925 2,209 2,493 2,777 3,061 3,351 3,641 3,930 4,220 4,510 4,799 5,103 5,407 5,896
Wall - Lt Wt above 4th floor Include Mezz. Floor
Page 10 of 46
P2
P3
ΣPL
41 39 39 39 39 39 39 39 39 39 39 39 39 39 39 39 39 39 39 59
0 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 16
0 31 31 31 31 31 31 31 31 31 31 31 31 31 31 31 31 31 31 47
41 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 122
805
157
612
1,573
Draft No. 1
ACI 314 Task Group B/C
Reference table Perimeter Frame
Based on Portal Method for horizontal force distribution
Level
Force to Frame Vs
Int Column V
Ext Column V
Int Col M
Ext Col M
Roof
Girder M
Girder Shear
46
3.3
Ext col axial Load PE
Int col axial Load PE
OTM*0.15/140
20
70.2
14.0
7.0
91
46
134
9.6
3
5
7
19
136.3
27.3
13.6
177
89
218
15.5
13
11
19
18
198.4
39.7
19.8
258
129
296
21.1
28
15
38
17
256.6
51.3
25.7
334
167
369
26.3
50
20
61
16
310.8
62.2
31.1
404
202
437
31.2
76
24
90
15
361.2
72.2
36.1
470
235
500
35.7
107
28
124
14
408.7
81.7
40.9
531
266
560
40.0
143
32
162
13
452.3
90.5
45.2
588
294
614
43.8
183
35
204
12
492.1
98.4
49.2
640
320
663
47.4
227
38
249
11
528.2
105.6
52.8
687
343
708
50.6
274
41
299
10
560.7
112.1
56.1
729
364
748
53.4
325
43
351
9
589.6
117.9
59.0
766
383
783
55.9
378
46
405
8
614.9
123.0
61.5
799
400
814
58.1
434
48
462
7
637.3
127.5
63.7
828
414
841
60.1
492
49
522
6
656.2
131.2
65.6
853
427
863
61.7
552
51
583
5
671.8
134.4
67.2
873
437
881
63.0
614
52
645
4
684.2
136.8
68.4
890
445
896
64.0
677
53
708
3
693.6
138.7
69.4
902
451
906
64.7
741
54
773
2
700.1
140.0
70.0
910
455
1,267
90.5
805
54
838
1
705.8
141.2
70.6
1,623
812
896
97
954
Page 11 of 46
Draft No. 1
ACI 314 Task Group B/C Preliminary design of structural wall
Reference ASCE 7-05
Material Propoerties Base Shear to structural walls
Load factor for E Factor seismic force ea panel
f c´
=
5
ksi =
f
=
60
ksi
V
=
0.85
x
=
3,999
kips
=
1.0
=
3,999
/
1,000
kips
Vu lw
=
30.5
=
Wall height
hw
=
270
ft
Consider wall thickness
h
=
14
in
Acv
=
14
x Sq in
= Minimum wall length based on
Required shear strength Wall reinforcement
For #6 @ 12" o.c. ea face
Vn
#
For 5 @ 12" o.c. ea face
For #5 @ 12" o.c. ea face
For #4 @ 12" o.c. ea face
4705
366
At lower story, walls resist 75 to 95% of story shear
in
Can increase after 1st iteration
ea pier
Acv 6 √ f c´ x
=
2,174
kips
=
1,000
/
=
1,666
kips
=
270
/
30.5
=
8.9
>
2
αc
=
2.0
ρt
=
0.88
=
0.00524
=
Acv (2 √fc´ + ρ t f )
hw/lw
12.2.5.1
366
5,124
Vu/φ
reg wt below 3rd Flr
4
=
Vn
For #5 @ 12" o.c. ea face
=
5,124
psi
Remarks
Eq (9-5)
Wall length
Gross wall area
5,000
ACI 318-05
Can increase to 8 √fc´ after 1st iteration
0.424 0.60
9.3.4
< Vn
Conservative to consider shear control
21.7.4 /
168 Eq (21-7)
=
5,124
x(
=
2,335
kips
h
=
14
in
Vn
=
5,124
x(
0.141
=
1,859
kips
>Vu/φ
h
=
14
in
Vn
=
5,124
x(
0.120
=
1,751
kips
>Vu/φ
h
=
12
in
Vn
=
4,392
x(
=
1,663
kips
h
=
12
in
Vn
=
4,392
x(
=
1,260
kips
0.141
+
0.314
)
Reg. Wt Conc
+
0.221
)
Reg. Wt Conc
+
0.221
)
Lt Wt conc.
0.120
+
0.258
)
Lt Wt conc.
0.120
+
0.167
)
Lt Wt conc.
> Vu/φ
Application of Resultant
hx
=
0..5 hn
=
135
Required moment strength
Mu
=
1,000
x
135
Page 12 of 46
Spcg may be changed after 1st iteration
ft
Due to dynamic behavior
Draft No. 1
ACI 314 Task Group B/C
Min. Ht. Of Boundary element Consider building displacement
=
134,978
kipft
Mu /φ
=
134,978
/
0.65
=
207,658
kip-ft
Mu /φ
=
134,978
/
0.90
=
149,975
kip-ft
φ may be increased based on εt
134,978
/
4000
=
ft
> lw
=
0.0015
x
270
34 T12.121
=
0.405
x
12
=
4.9
in
Mu /4Vu =
δσε
δu
δu/hw
c
Cd δ
=
12.12.1
=
5.5
x
=
26.7
in
=
26.7
/
=
0.008
>
0.007
=
lw
Conservative for dual system
4.9
Δs = 0.025hx = 81 in. 3240
600(δu/hw)
Eq (21-8)
=
30.5
/(
600
x
=
6.2
ft =
74
in.
=
0.80
x
6.2
=
4.9
ft
c0.1lw
=
74
-
36.6
=
37.3
< 51"
c/2
=
74
/
2
=
37.0
< 51"
T
=
134,978
/(
=
5,209
kip
=
0.9
x
3,005
=
2,705
=
5,209
-
2,705
=
2,505
kip
a
0.008
) R10.2.7
Boundary element
Extend of boundary element or Appro. Tension force Less 0.9 D Net tensile force due seismic Minimum tension reinf.
Try 36- #11 Total factored load to wall
PD PE As
2,505
=
46.4
=
1.56
=
56.2
=
5,896
x
1.2
+
1,573
x
1.6
=
9,592
kip
Pu/φ
=
9,592
/
0.65
Pu
=
5,896
x
1.2
+
1,573
x
1.0
=
8,648
kip
Pu/φ
=
8,648
/
0.65
Pu
=
5,896
/
0.9
=
6,551
kip
Pu/φ
=
6,551
/
0.65
Ag
=
3,060
+
3,696
=
6,756
As Pu
1.2D+1.0L+1.0E
0.9D + 1.0E
Conc Section at Level 1
-
2.5
)
x
60
)
PE / φ f
=
Required axial strength 1.2D+1.6L
=
28.4
/(
0.9
sq. in. x
36
May not be adequate for compression
sq. in.
sq. in.
Page 13 of 46
Eq.(9-2)
=
14,757 Eq (9-5)
=
φ may be increased
13,305 Eq (9-7)
=
10,079
φ may be increased
Ignore L-shape in prelim design
Draft No. 1
ACI 314 Task Group B/C
Average compressive stress
Ast
=
181.0
+
Pu / Ag
=
9,592
/
=
1.4
ksi
Po
Nominal axial strength
at zero eccentricity
Nominal axial strength
18.5
199.4
<
0.35 f c'
=
1.75
ksi
>
0.10 f c'
=
0.5
ksi
=
0.85 f c' (Ag-Ast) + f Ast 0.85
x
5.0
+
60
x
199.4
=
27,865
+
11,966
Po
=
39,832
kips
Pn
=
x
Total in wall panel
6,557
0.80 Po
=
in2
6,756
=
Pu/φ
=
Eq (10-2)
31,865
kips
=
9,592
/
=
14,757
0.65
9.3.2.2
Nominal Moment Strength
At Pn = 0
Ignore rebar at compression side and wall reinf.
Strain diagram
0.003
εt
ε =0.011
c a
Force diagram T1
T2
T3
Cc
363
Nominal moment strength
T1
=
60
x
74.88
=
4493
48 # 11 at ends
T2
=
60
x
15.60
=
936
10 # 11 in web
T3
=
60
x
3.52
=
211
count 8 # 6 effective
C
=
Σ
=
5,640
a
=
C /( 0.85 f c' b)
=
44.2
in.
c
=
44.2
/
0.80
=
55.3
in.
εt
=
0.003
x
307.7
/
55.3
=
0.017
>
0.005
=
4,493
x
26.5
=
119,202
+
936
x
23.4
=
21908.8
+
211
x
20.4
=
4309.93
=
145,421
Mn
At Pn = 0 Mn
T
k-ft
Page 14 of 46
kips
10.3.4
< 51.0
Tension control
Draft No. 1
ACI 314 Task Group B/C
Calculate Pb, Mb
at balance strain condition Strain diagram
0.003 0.00207
c
εt
a
Force diagram Cs3 T1
T2
T3
Cs2
Cs1
Cc2
Cc1
0.003
363 c
At Cs1 At Cs2 At Cs3 At T1 At T2 At T3
=
363
x
=
215
in.
d-c
=
148
in.
a
=
0.80
x
=
172
in.
=
0.00264
>
=
0.00212
>
=
0.00162
<
=
0.00175
<
=
0.00123
<
=
0.00073
<
ε1 ε2 ε3 ε1 ε2 ε3
Compressive force
Σ
0.0051
215
12.2.7.3
ε ε ε ε ε ε
x = 215-25.5 =189.5 x = 215-63 =152 in. x = 215 -99 =116 in x = 148 -22.5= 125.5 x = 148 - 60 = 88 in x = 148 -96 = 52 in
Cc1
=
0.85 f c'b(51)
=
6,503
Cc2
=
0.85 f c'b(a-51)
=
7,192
Cs1
=
74.88
x
55.8
=
4,175
Cs2
=
15.60
x
55.8
=
870
Cs3
=
3.52
x
42.7
=
150
=
18,889
C
f s' = f s - 0.85f c' f s = Es εs kips f s = Es εs
T1
=
74.88
x
50.9
=
3,811
T2
=
15.60
x
35.7
=
557
T3
=
3.52
x
21.1
=
74
=
4,442
kips
Σ T
Moment about C.L of wall
/
Pb
=
18,889
-
4,442
=
14,447
kips
Cc1
=
6,503
x
13.1
=
85345.3
k-ft
Cc2
=
7,192
x
6.0
=
42889.9
Cs1
=
4,175
x
13.1
=
54791.1
Cs2
=
870
x
10.0
=
8697
Cs3
=
150
x
7.0
=
1051
T1
=
3,811
x
13.1
=
50013.1
T2
=
557
x
10.0
=
5569.59
T3
=
74
x
7.0
=
520
Mb
=
Page 15 of 46
=
248,878
k-ft
Draft No. 1
ACI 314 Task Group B/C Calculate Pn, Mn
at 0.005 strain condition Strain diagram
0.003 0.0050
c
εt
Tension control when εt > 0.0050
a
Force diagram Cs3 T1
T2
T3
Cs2
Cs1
Cc2
Cc1
x
0.003
363
At Cs1 At Cs2 At Cs3 At T1 At T2 At T3
c
= =
136
in.
d-c
=
227
in.
a
=
0.80
x
=
109
in.
=
0.00244
>
=
0.00161
<
=
0.00082
<
=
0.00450
>
=
0.00368
>
=
0.00288
>
ε1 ε2 ε3 ε1 ε2 ε3
Compressive force
Σ
363
0.0080
136
ε ε ε ε ε ε
x = 136-25.5 =110.5 x = 136-63 =73 in. x = 136 -99 =37 in x = 227 -22.5= 204.5 x = 227 - 60 = 167 in x = 227 -96 = 131 in
Cc1
=
0.85 f c'b(51)
=
6,503
Cc2
=
0.85 f c'b(a-51)
=
3,445
Cs1
=
74.88
x
55.8
=
4,175
Cs2
=
15.60
x
42.5
=
663
Cs3
=
3.52
x
19.5
=
69
=
14,853
C
f s' = f s - 0.85f c' f s = Es εs kips f s = Es εs
T1
=
74.88
x
60.0
=
4,493
T2
=
15.60
x
60.0
=
936
T3
=
3.52
x
60.0
=
211
=
5,640
kips
Σ T
Moment about C.L of wall
/
Pn
=
14,853
-
5,640
=
9,213
kips
Cc1
=
6,503
x
13.1
=
85345.3
k-ft
Cc2
=
3,445
x
8.6
=
29584.4
Cs1
=
4,175
x
13.1
=
54791.1
Cs2
=
663
x
10.0
=
6628
Cs3
=
69
x
7.0
=
480
T1
=
4,493
x
13.1
=
58968
T2
=
936
x
10.0
=
9360
T3
=
211
x
7.0
=
1478
Mn
=
Page 16 of 46
=
246,635
k-ft
Draft No. 1
ACI 314 Task Group B/C
Confinement Reinforcement
Reinf. ratio
ρ
=
74.88
/
1530
=
0.0489
In-plane direction
bc
=
51.0
-
4.0
=
47.0
f c'/f t
=
5
/
60
=
0.08333
Ash
=
0.09sbcf c'/f t
=
0.353
Less than 8%
Eq. (21-4)
s
For s = 6 inches
Ash
=
2.12
Sq. in.
# 5 Hoop plus 5 #5 cross ties
Ash
=
2.17
Sq. in.
= Out-of-plane direction
bc
=
30.0
-
4.0
=
26.0
f c'/f t
=
5
/
60
=
0.08333
Ash
=
0.09sbcf c'/f t
=
0.195
s
For s = 6 inches
Ash
=
1.17
Sq. in.
# 5 Hoop plus 2 #5 cross ties
Ash
=
1.24
Sq. in.
Within the 24" of web
21.7.6.5
ρ
=
15.60
/
336
=
0.04643
bc
=
24.0
-
4.0
=
20.0
f c'/f t
=
5
/
60
=
0.08333
Ash
=
0.09sbcf c'/f t
=
0.150
In-plane direction
s
For s = 6 inches
Ash
=
0.90
Sq. in.
#5 Hoop plus 2 #4 cross ties
Ash
=
0.89
Sq. in.
# 4 Grade 40
= Out-of-plane direction
bc
=
14.0
-
4.0
=
10.0
f c'/f t
=
5
/
60
=
0.08333
Ash
=
0.09sbcf c'/f t
=
0.075
s
For s = 6 inches
Ash
=
0.45
Sq. in.
# 5 Hoop
Ash
=
0.62
Sq. in.
Development of horizontal wall reinforcement For # 6 bars
ld
f c' = 5000 psi
For # 5 bars f c' = 4000 psi
ld
=
d (f
ψt ψe λ)/(25√f c')
=
34
=
25.5
=
38
=
23.7
d in. d in.
Page 17 of 46
12.2.2 Straigth development in boundary element
Straigth development in boundary element
Draft No. 1
ACI 314 Task Group B/C
Boundary Element (Cont.) Reference ASCE 7-05
ACI 318-05
Check when boundary reinforcement may be discontinue
Consider the boundary element size is reduced to 30 x 30 at upper stories Size
Area
x
Ax
2
2
Ad /12
2.5
2.5
6.25
14.0
1225
3
1.0
25.5
25.5
0
0
1382
2.5
2.5
6.25
14.0
1225
3
2450
1388
=
3838
ft4 =
5472
2
38.0 I=
2450
Ag =
38.0
c=
183
Level
PD
+
1388
x
144
=
79,590,816
in
in. PL
Pu
Mu
kip
kip -ft
Pu/Ag
Muc/I
Σf c
20
504
119
723
1520
0.132
0.042
0.174
19
788
197
1143
4472
0.209
0.123
0.332
18
1,072
276
1562
8771
0.285
0.242
0.527
17
1,356
354
1982
14330
0.362
0.395
0.758
16
1,640
433
2401
21064
0.439
0.581
1.020
15
1,925
511
2820
28891
0.515
0.797
1.313
0.15 f c' =
0.600
ksi
May discontinue boundary element at the 18 floor
21.7.6.3
28.00
1.25
< 0.15f c'
3.00
22.00
2.50 1.17
PLAN
Page 18 of 46
3.00
1.25
Remarks
Draft No. 1
ACI 314 Task Group B/C
30.0
14.0 4 spcg @ 12" 48 #11
10 #11
51.0
24.0
8 #6 48.0
DETAIL Confinement not shown for clarity
40,000 P0
Pn 30,000
P (kip) 20,000 Pn PM
10,000
Min. eccentricity
εt = 0.005
0
Mn 100,000 Moment
200,000 kip-feet
Simple Interaction Diagram
Page 19 of 46
Draft No. 1
ACI 314 Task Group B/C
Rf
Bar A
Bar B
48 # 11
10 # 11
20 19 18 17
# 5 @ 12" EWEF h = 12 "
16 15 14 13 12 11 10 9 8 7 h = 14" 6
# 5 @ 12" EWEF
5 4 Bar B
Bar B
3 Bar A
Bar A
2 h = 14" #6 @ 12 EWEF 1
WALL ELEVATION
Page 20 of 46
Draft No. 1
ACI 314 Task Group B/C
5 #5 Crossties @ 6" o.c.
#
5Hoops @ 6" o.c.
Wall Reinf.
30.0
14.0
2 #4 Crossties @ 6" o.c. ld
48 #11 51.0
10 #11 24.0
PLAN DETAIL BOUNDARY ELEMENT
5. Moment Frame Design 5.1 Two moment frames in each direction Reference ASCE 7-05
Min. Seismic shear to moment frames
Vx
=
25%
x
Torsion - Accidental
ecc
=
5%
x
=
7.0
ft
Torsion
T
=
Torsional stiffness
J
= =
Additional force
ΔVx
Force per frame
Vx + ΔVx
12.2.5.10
140
12.8.4.2
7 Vx 4R (70)2 19600
=
TcR/J
=
7Vx R
=
ΣVx
ACI 318-05
0.025
R x
70
/
Vx
=(
0.125
+
=
0.150
Vx
Design frame for
Fx
=
30%
Vx
Or per frame
Fx
=
15%
Vx
Page 21 of 46
0.025
) Vx
19600
R
Draft No. 1
ACI 314 Task Group B/C
5.2 Seismic Force distribution using Portal Method ΣV12
=
3521
x
15%
=
528
V11
=
216
x
15%
=
32
ΣV11
=
3738
x
15%
=
561
kips
MA12
=
53
x
6.5
=
343
kip-ft
MA11
=
56
x
6.5
=
364
MAB
=
=
708
kip-ft
Axial Load
PA12
=
274
kips
Axial Load
PA11
=
325
kips
MB12
=
106
x
6.5
=
687
kip-ft
MB11
=
112
x
6.5
=
729
MBA =MBC
=
(MB-12+MB-11) /2
=
708
VBA =VAB
=
(MAB+MBA) /28
=
51
At 11th Floor
Exterior Column
Interior Column
Girder shear
At 3rd Floor
Exterior Column
Axial Load Interior Column Axial Load
Girder shear
MA-12+MA-11
kips
kip-ft kips
ΣV4
=
4624
x
15%
=
694
V3
=
43
x
15%
=
6
ΣV3
=
4667
x
15%
=
700
kips
MA4
=
69
x
6.5
=
451
kip-ft
MA3
=
70
x
6.5
=
455
MAB
=
MA-12+MA-11
=
906
kip-ft
PA4
=
741
kips
PA3
=
805
kips
MB4
=
139
x
6.5
=
902
kip-ft
MB3
=
140
x
6.5
=
910
PB4 MBA =MBC VBA =VAB
=
54
kips
=
(MB-12+MB-11) /2
=
906
=
(MAB+MBA) /28
=
65
Page 22 of 46
kips
kip-ft kips
Draft No. 1
ACI 314 Task Group B/C
Remarks
Rf Level
70 A
B
C
3
E
F
3
7
14
14
12th Floor
14
14
11th Floor
Vu = OTMu =
> 25 %
D
528 41,791
kips kip-ft
Vu =
561
OTMu =
49,080
kips kip-ft
Line of symmetry 53
106
106
106
106
53
B
C
D
E
F
Above Flr Line Below Flr Line
32 A
`
56
112
112
4th Floor
112
112
3rd Floor
Vu =
694
OTMu =
108,199
69
kips kip-ft
Vu =
700
OTMu =
117,300
kips kip-ft
139
139
139
139
69
B
C
D
E
F
6 A
70
140
Page 23 of 46
140
140
140
Draft No. 1
ACI 314 Task Group B/C
Loads
Dead Load
D
=
0.09
x
15.2
5.9
x
0.15
=
2.25
k/ft
=
0.04
x
=
0.61
k/ft
1.2D
=
2.70
k/ft
1.2D +1.6 L 1.2D +1.0L+1.0E
=
3.68
k/ft
=
3.31
k/ft
0.9D+1.0E
=
2.03
k/ft
FEMTL
=
FEMD
=
+ L Load combinations
Fixed end moment Member stiffness -
To edge of slab
wl2/12
15.2
=
187.0
k-ft
=
147.3
k-ft
Consider column far end fixed Ic
=
0.70Ig
=
4.73
ft4
Ig
=
0.35Ig
=
1.77
ft4
E
=
K c
=
4EIc/L
=
754720
K g
=
4EIg/L
=
131402.1
DFAB
=
Ig/Σ(Ic+Ig) =
DFBA
=
519119.5
Ksf
0.080 0.074
Gravity Load moment distribution
Spandrel wt Line of symmetry -68 0 86 A Service Load
8.5 B
-68 C
D
F
D.F.
Service Load
FEM D
-147
147
-147
147
-147
147
36 Sq column
TL
-187
187
-187
187
-187
187
27x36 Girder
B.J.
15.0
2.9
-2.9
2.9
-2.9
C.O.
0.1
0.6
-0.1
0.1
-0.1
0
0.0
0.0
0.0
0.0
-172
191
-190
190
-190
f c' = 4000
E
B.J. -M
Page 24 of 46
-147
147
-147
147
0
0
-12
0
0.5
0 0 135
Draft No. 1
ACI 314 Task Group B/C
5.3 Based on two cycle moment distribution
Exterior column
Interior Column
Girder at ext. support
Girder at int. support
MD+L
=
86
k-ft
MD
=
68
k-ft
ML
=
18
k-ft
ME
=
451
k-ft
MD+L
=
8
k-ft
MD
=
0
k-ft
ML
=
8
k-ft
ME
=
910
k-ft
MD+L
=
-172
k-ft
MD
=
-135
k-ft
ML
=
-36
k-ft
ME
=
906
k-ft
MD+L
=
-190
k-ft
MD
=
-147
k-ft
ML
=
-43
k-ft
ME
=
906
k-ft
5.4 Column axial load (Between 3rd and 4th Floor)
Ext column
PD)A4
=
812
kip
PL)A4
=
148
kip
PD)A3
=
860
kip
PL)A3
=
157
kip
PD)B4
=
1302
kip
PL)B4
=
272
kip
PD)B3
=
1379
kip
PL)B3
=
289
kip
f c'
=
5
ksi
f
=
60
ksi
(1.2D+1.6L)
-Mu
=
-245
(1.2D+1.0 L+1.0E)
-Mu
=
-1177
(1.2D+1.0 L-1.0E)
-Mu
=
635
(0.9D+1.0E)
+Mu
=
773
kft kft kft kft
ln
=
28.0
-
=
25.0
ft
bw
=
27
in
h
=
36
in
Int Column
Above 3rd Flr Below 3rd Flr Above 3rd Flr Below 3rd Flr
Frame Girder Design (3rd floor)
Factored Moment
Aspect ratios
Page 25 of 46
(9-2) (9-5)
(9-7) 3.0 > 10 in.
21.3.1
Draft No. 1
ACI 314 Task Group B/C
ln /d
=
8.3
>
4
bw/h
=
0.75
>
3
Min. hc
=
20
x
1.128
=
22.6
<
36 in.
=
36.0
-
3
=
33.0
in
Eff. d
Minimum column width
Longitudinal reinf.
21.3.2
Try 6 # 11 top and
Min. As
=
200bwd/f =
3.0
Sq. in.
Max. As
=
0.025bwd =
22.3
Sq. in
-a
=
f As / 0.85f c'
=
60
x
9.36
0.85
x
5
4.9
in.
4 - # 11 bottom
= c
=
a/0.80
=
6.1
-Mn
=
f As (d-a/2) 60
x
9.36
x(
33.0
2.4
=
1430
kft
=
> -εt Similarly
+a
+Mn
With 90º std hook For Straight top bar For Straignt bott. Bar
ldh
ldh
ldh
Mu/φ
)/
=
1307.38
kft /
=
0.003
x
26.9
=
0.013
>
0.005
=
x
60
x
6.24
0.85
x
5
=
3.3
in.
=
60
x
6.24
x(
33.0
1.6
)/
=
979
kft =
859
kft
>
Mu/φ
=
f d / (65√f c' )
=
18
in.
=
3.25
x
=
60
in.
=
2.5
x
=
150
in.
Page 26 of 46
x
27
)
12
φ = 0.90 6.1
27
)
12
(21-6) 18 60
21.5.4.2
Draft No. 1
ACI 314 Task Group B/C
21.3.4
Girder Shear Strength (3rd Floor)
wu=1.2D+1.0L +1.0E
-M
r
=
1752
k-ft
Based on 1.25f
+M
r
=
1207
k-ft
Based on 1.25f
wuln /2
=
3.31
x
=
41.4
kip
Ve
Consider #4 ties 4"o.c.
=
118.4
=
160
kips
>(
160
+
>
101
kips
Vc
=
0
Vs
=
Beyond 2h from support
Vu
Vu / φ Vc At 12" o.c.
2
41.4 41.4
)/2
for 2xh from face of support
Av f bw/s 0.40
x
=
162
kips
60
x
27
504
kips
=
Vc + Vs
=
0
=
162
kips
≅
Ve
=
160
kips
=
41.4
x
6.5
/
12.5
+(
1177
+
635
)/
25.0
+
=
94
kips
=
94
/
=
125
kips
=
/4
8 √f c' bw d
= Vn
±
= =
/
(-M r + M r )/ln ± wuln/2
=
Max Vs
25.0
162
0.75
2 √f c' bw d
=
126
Vs
=
54
Vn
=
180
kips kips
>Vu / φ
Design Exterior Column (Between 3rd and 4th Floor)
f c'
=
5
ksi
f
=
60
ksi
-Mu
=
110
kft
Pu)A4
=
1211
kip
Above 3rd Flr
Pu)A3
=
1283
Below 3rd Flr
-Mu
=
550
kip kft
Pu)A4
=
1863
kip
Above 3rd Flr
Pu)A3
=
1994
Below 3rd Flr
-Mu
=
-514
kip kft
Pu)A4
=
382
kip
Above 3rd Flr
Pu)A3
=
317
kip
Below 3rd Flr
Factored Moment (1.2D+1.6L)
(1.2D+1.0 L+1.0E)
(1.2D+1.0 L-1.0E)
Page 27 of 46
(9-2)
(9-5)
Draft No. 1
ACI 314 Task Group B/C
(0.9D±1.0E)
Aspect ratios Pu > #
Try 16 10 Vert. At Pn = 0
+Mu
=
390
kft
Pu)A4
=
-10
kip
Above 3rd Flr
Pu)A3
=
-75
kip
Below 3rd Flr
lu
=
13.0
-
=
10.0
ft
b=h
=
36
in
b/h
=
1
>
Agf c´/10
=
648
ρ
=
20.32
/
1296
=
0.015679
>
1%
=
680
/
153
=
4.45
in
=
4.45
/
=
5.56
in
=
0.0030
x
27.44
=
0.0148
0.005
=
680
> x (
=
17,538
=
1,462
ΣMnc
=
2923
ΣMnb
=
1430
6/5ΣMnb
=
1716
<
ΣMnc
=
1863
/
=
2866
Mnc
=
2850
kip kft
Pu/φ
=
317
/
=
487
=
1650
kip kft
a c
εt At Pn = 0
At
At
Mnc
Pu/φ
Mnc
(9-7)
3.0 21.4.1 0.4
kip
21.4.2
9 bars effective
0.80
28.0
/
5.56 Tension control
-
2.2
)
Ave. d = 28.0
kip-in kft kft kft kft
Conservative See girder abv
21.4.2.2 0.65
> Mu/φ
=
847
k-ft
OK
=
791
k-ft
OK
0.65
> Mu/φ
Design Interior Column (Between 3rd and 4th Floor)
f c'
=
5
ksi
f
=
60
ksi
-Mu
=
14
kft
Pu)B4
=
1999
kip
Above 3rd Flr
Pu)B3
=
2118
Below 3rd Flr
-Mu
=
919
kip kft
Pu)B4
=
1889
kip
Above 3rd Flr
Pu)B3
=
1998
Below 3rd Flr
-Mu
=
-902
kip kft
Factored Moment (1.2D+1.6L)
(1.2D+1.0 L+1.0E)
(1.2D+1.0 L-1.0E)
Page 28 of 46
(9-2)
(9-5)
Draft No. 1
ACI 314 Task Group B/C
(0.9D±1.0E)
Aspect ratios Pu >
Pu)B4
=
1782
kip
Above 3rd Flr
Pu)B3
=
1891
Below 3rd Flr
+Mu
=
910
kip kft
Pu)B4
=
1118
kip
Above 3rd Flr
Pu)B3
=
1
kip
Below 3rd Flr
lu
=
13.0
-
=
10.0
ft
b=h
=
36
in
b/h
=
1
>
Agf c´/10
=
648
ρ
=
20.32
/
1296
=
0.015679
<
6%
Larger than 1%
=
680
/
153
9 bars effective
=
4.45
in
=
4.45
/
=
5.56
in
=
0.0030
x
27.44
=
0.0148
0.005
=
680
> x (
=
17,538
=
1,462
Mu/ φ
=
910
ΣMnc
=
2923
ΣMnb
=
1430
6/5ΣMnb
=
2890
<
ΣMnc
=
1889
/
=
2906
Mnc
=
2750
kip kft
Pu/φ
=
1118
/
=
1721
=
2600
kip kft
#
Try 16 10 Vert. At Pn = 0
a c
εt At Pn = 0
At
At
Mnc
Pu/φ
Mnc
(9-7)
3.0 21.4.1 0.4
kip
21.4.2
0.80 /
5.56 Tension control
28.0
-
/ kft
0.9
=
+ kft
979
2.2
)
Ave. d = 28.0
kip-in kft 1011
OK Conservative
=
2409
See girder abv
21.4.2.2 0.65
> Mu/φ
=
1413
k-ft
OK
=
1400
k-ft
OK
0.65
> Mu/φ
Design Column Shear Strength (Between 3rd and 4th Floor)
For 36 x 36 column
f c'
=
5
ksi
f
= = =
1.25 75 1.0
x ksi
φ Girders
ΣM
r
½ΣM
r
60
= =
1752 2959
+ 1207 ft-kip
=
1480
ft-kip
Page 29 of 46
21.3.4
See Girder abv
Draft No. 1
ACI 314 Task Group B/C
Pu / φ
=
1782
Column
M
r
=
3050
ft-kip
Design for
M
r
=
1480
ft-kip
At
/
0.65
=
2741
Interaction diagram R 21.3.4
ΣM pr /
Probable shear strength
From Portal analysis
Consider ties @ 5.5"o.c. 5 legs
Ve
= = =
1480 148
/ kip
Vu
=
139
kip
Vu/ φ
= =
139 213
/ kip
Vc
=
0
Vs
= = =
Av f bw/s 1.55 x 582 kips
= =
8 √f c' bw d 672 kips
= = =
Vc + Vs 0 582
+ kips
148
kips
Max Vs Vn
> Vu/ φ = Transverse reinforcement Try #5 ties at
Or Max spacing USE:
Consider M pr top and bottom the same Due to seismic
lu
10
0.65
60
x
36
/ s
582
OK
s
=
5.75
in
hx
=
8
in.
Ach
=( =
36 1056
Sq in
Ag
=
1296
Sq in
Ash
= =
0.3 (sbcf c´ /f t)[(Ag/Ach) - 1] 1.17 Sq. in.
(21-3)
Ash
= =
0.09 sbc f c´ /f t 1.55 Sq. in.
(21-4)
s0
on center 3.5
) 2
= 4 + (14 - hx)/3 (21-5) = 6 in 36 Square Column w/ 16 # 10 Vert. #5 Hoops plus 3 #5 cross ties @ 5.75" o.c. for 3 feet top and bottom and through joint, balance @ 12" o.c.
Page 30 of 46
Say OK
Draft No. 1
ACI 314 Task Group B/C
6.
Preliminary Material Quantities for Superstructure only: 6.1
Typical Shear-wall (4 total)
4.25ft x 2.5ft (typ.)
22ft x 1.17ft (typ.)
48#-11
48 #-11
10-#11
32-#6
10-#11 10-#11
32-#6
10-#11
48#-11
Total weight of longitudinal reinforcement:
•
# 11 – 184 * (4 walls) * 270 ft * 5.31 lb/ft/2000:
527 tons
•
# 6 – 64 * (4 walls) * 270 ft * 1.50 lb/ft/2000:
52 tons
Total weight of transverse reinforcement: Hoops at boundary elements:
•
# 5@6” – 26’/ea * (12 elem.) * (270 ft/.5) * 1.04 lb/ft/2000:
88 tons
Cross-ties at boundary elements:
•
5-# 5@6” – 2’/ea *5* (12 elem.) * (270 ft/.5) * 1.04 lb/ft/2000:
Page 31 of 46
37 tons
Draft No. 1
ACI 314 Task Group B/C
Hoops at wall elements:
•
# 5@12” – 24’*(2) * (8 elem.) * (270 ft) * 1.04 lb/ft/2000:
•
Total weight of reinforcement in shear walls
54 tons
758 tons
Estimated quantity of concrete:
•
Shear walls: o
6.2
84 sq.ft.(270ft)*(4 locations)/27
3,360 cy
Columns: Total weight of longitudinal reinforcement:
36 x 36 Col (24 locations) 16 # 10 Vert.
# 11 – 16 * (24) * 270 ft * 5.31 lb/ft/2000:
•
Total Wt per square foot of total building area – 1033T(2000)/392,000 sq.ft. (with .5 psf for miscellaneous steel)
275 tons
~ 6 psf
Estimated quantity of concrete:
•
Columns: o
9 sq.ft.(270ft)*(24 locations)/27
Page 32 of 46
~2,200 cy
Draft No. 1
ACI 314 Task Group B/C
6.3
Floor slab: Estimated quantity of reinforcement:
\
•
4.5” lt. wt. concrete slab (Est. quantity of rebar)
3.5 psf
Estimated quantity of concrete:
\
•
slabs: o
140’x140’x(4.5”/12)*19fl/27
Page 33 of 46
~5,200 cy
Draft No. 1
ACI 314 Task Group B/C
Preliminary Design and Economical Impact of Simplified Design of R/C Structures Gravity/Lateral Force Resisting System
by Michael Mota and James S. Lai
ACI Spring Convention 2007
Simplified Design of Concrete Structure
Page 34 of 46
1
Draft No. 1
ACI 314 Task Group B/C
Page 35 of 46
Draft No. 1
ACI 314 Task Group B/C
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Draft No. 1
ACI 314 Task Group B/C
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ACI 314 Task Group B/C
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Draft No. 1
ACI 314 Task Group B/C
Page 39 of 46
Draft No. 1
ACI 314 Task Group B/C
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Draft No. 1
ACI 314 Task Group B/C
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Draft No. 1
ACI 314 Task Group B/C
Page 42 of 46
Draft No. 1
ACI 314 Task Group B/C
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ACI 314 Task Group B/C
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Draft No. 1
ACI 314 Task Group B/C
Page 45 of 46
