Answer Happy

PROBLEMS 527 adequately prevented (i.c., a bruced frame). Use S'E 3000 psi and S. = 60.000 psi. Use the AC1 moment magnifier method. 13.5 Repeal Problem 13.4. excepl consider the pri- mary hending moment constant over the height of the column. (13.6 Assume that the memher (Column B) in rublem 13.4 is part of an unbreed frame and that max- imum nonsway moments Maru 28 and 20 ft-kips due to dead and live loads, respectively. Also, a maximum M., sway nomeni of 85 11- kips due to strength-level wind lou must he carried. The axial compressive loads are 30 hips service dead loud and 40 hips service line sul The total factored load LP, to all live columns in the story is 500 hips for the loud combination 1.21): 1.0M +0.57. Investigate the adequacy the H.in. wuare exterior column (column B. I found to be inadequate. redesign the number assuming that the loadings are 13 alleled hy. change in member stillness, (13.7 Determine the adequacy of the 16-in. quare first story column (column () of the figure for Problem 13.2. which is carrying a service axial loud of 370 kips and a primary hending moment of 121 A kips (assume logics 70% dead loud. The primary hending nioment varies from a maximum at the top to zero at the bottom and joint translation is adequately prevented. Use '= 5000 psi and = 60.000 psi. the ACI moment magnifier method. (13.8 Assume that the member (column () of Problem 13.7 is part of an umbraced frame. The axial leaths are 45 kips deud load and 60 kips live lead. The bending moments are 30 n-kips dead Roal, 22 ft- kips live load, and I10 A-kips wind koud. Investigate the adequacy according to the moment magnilier method of the ACI Code. If not adequate, redesign assuming the ladings are not afected by changes in member stillnesses. The total factored load EP, to all columns in the lower story is 865 kips for lead combination 1.21)+LOW+0.51.. 13,9 Design column A for the unbraced frame of the ligure for Problem 13.9 for the lead combination of 1.21 + 1.OW+ 1.0.1 Assume that the columns will support areas having live leciels greater than 100 psl.) The axial compression is 112 hips cleau load and 112 Lips live laul; hending moment is 35 R-hips Jeal load. 35 fi-hips live load, anul TIX A-kips winul load. Consider only the dead Town to be sustained. The factored asial bud !". cili the interior columns is 1.8 times that on the Esterior columns, Select al quare member l contain approximately 2 y reinforcement. the 1'5000) pi.J. = 60,000 psi, and the moment magnilier methal of the ACT Code. 13.10 (a) Redesign the column used in Problem 13.9 l'Acept for service locul use an axial com pression of 132 Lips dead load and 132 Lips Ine lid, and hending moments M. of 26 M-hips cleau luad, 26 ft-hip live load. and 123 n-kips wind lead. The length for column 1 is 20 st instead of 21 n. (b) llou much smaller could the member have heen if the frame had heen adequately braced to prevent joint translation? 13.11 (a) Redesign the columns used in Problem 13.9 except use 18 A instead of 21 n for the length of column.1. (b) How much smaller could the member are heen if the frame hud heen adequately braced to prevent joint translation?