1918 WALL ST 2018-01-02 MF Import

E Plan Check No. 1328 Byron Backstrom August 24, 1983 Page Ten d. The distribution analysis should include calculations as to how the rigidities of the walls with openings were determined. e. A diagrahm would be helpful to identify all the walls which were con- sidered part of the lateral force resisting system in both directions. 17. The combined footing analysis of all shear wall footings should be made based on dead load only for uplift and dead load plus live load for maximum bearing: a. Calculation Sheet F-8 shows a net uplift (6.95 K/sq.ft. - 4.53 1:/sq.ft.= 2.42 K/sq.ft.) This is not an acceptable solution. Further,the allowable soil bearing value is exceeded. b. Calculation sheet F-9 shows an uplift value equal to 6.17 ,./:;q•ft. which exceed the axial bearing value of 4.3 K/sq.ft. There appears to be a net uplift on this footing systen. c. The combined footing system shown on Sheet F-12 of the calculations should be analyzed based on the actual center of gravity of the gravity loads and a more precise section moduli. The approximate system may not be conser- vative. In addition, the easterly participating footings are rather re- mote from the shear walls which imposes the seismic overturning moments Therefore, additional reinforcement in the footing may be necessary to de- velop the calculated bearing pressures. d. Calculation Sheet F-14 shows a soil bearing of 13.1 K/sq.ft. which is greater than the allowable soil -bearing equal to 10.64 K/sq.ft. if 66.7' length is used, additional bottom steel may be required as well as top steel for uplift to develop columns B-6 and B-9 and the four columns along grid line B + 7.0. The wall boundary steel should be developed into the foundation to secure the balancing dead load from the columns. e. For the system shown on calculation Sheet F-16, comments similar to Item c and d above apply. 18. Where a column is used as part of the shear wall flange steel, the lap of the steel should be in accordance with your Schedule 16/S1.2, not 30 diameter lap as indicated on 1/15.2. 19. Columns which support the shear wall should be constructed as required for ductile concrete columns for its entire height. Section 2626(4)E. Section 4/2.2 20. t noincludeddrift witthprovisions thedesign calculationsshould Sectionshown. 2312(h;ft calcu- 21. Framing elements not required by design to be part of the lateral force resist- ing system should be investigated _,nd shown to be adequate for load carrying capac- ity and induced moment due to 3/K x the distortions resulting from the code required