Distribution of Forces for Transverse Seismic Forces
Rd2
Element
R
d
Rd
Torsional
Force
(kip)
CMU Wall A1-A2*
6682
-8.27
-55260
457001
-0.546
CMU Wall B1-B2
4648
11.73
54521
639532
0.539
Braced Frame 1A-1B
316
20
6320
126400
0.062
Braced Frame 2A-2B
316
20
6320
126400
0.062
1349333
Σ
*Note: The torsional force to wall A1-A2 and I1-I2 acts in the opposite sense of the direct shear force. Only forces
that are additional will be considered. Therefore, the torsional forces to walls A1-A2 and I1-I2 will be taken as zero.
Distribution of Forces for Longitudinal Seismic Forces
Rd2
Element
R
d
Rd
Torsional
Force
(kip)
CMU Wall A1-A2
6682
8.27
55260
457001
0.988
CMU Wall B1-B2
4648
11.73
54521
639532
0.975
Braced Frame 1A-1B*
316
-20
-6320
126400
-0.113
Braced Frame 2A-2B*
316
20
6320
126400
0.113
Σ
1349333
*Note: Since the braced frames 1A-1B & 2A-2B are symmetrical, use F = 113 # for both frames (Earthquake force
can act in either direction, and the only eccentricity is due to accidental eccentricity which means the center of mass
can be on either side of the center of rigidity).
Determine total shear forces to vertical resisting elements (Direct shear + Torsional force)
Note: The vertical elements (shear walls and braced frames) will be designed for the shear force that acts below the
mezzanine level; i.e. the upper braced frames and portions of shear walls above the mezzanine level will be designed
for the shear force levels at the base of the element.
Transverse Seismic Forces:
Element
Direct Shear Torsional
Total Shear
Force
Shear Force
Force
(kips)
(kips)
(kips)
1 inch = 25.4 mm
CMU Wall A1-A2
13.22
0.00
13.22
1 foot = 0.305 m
CMU Wall B1-B2
4.61
0.54
5.15
1 kip = 4.448 KN
CMU Firewall E1-E2
10.90
0.00
10.90
CMU Wall H1-H2
4.61
0.54
5.15
CMU Wall I1-I2
13.22
0.00
13.22
Typical Braced Frame Bay
0.00
0.06
0.06
H1-34
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