5316 ROCKEFELLER AVE 2025-03-10 - Laserfiche WebLink

PROJECT NAME: HULTS RESIDENCE JOB: X10-2854 Required steel area, As= MU /[4 Py(j d)] Assume jd= d- a/2 = 0.875d=0.875(8.50) = 7.44in A,s= 367(12)/[0.90(60000)(7.44)] = 0.011 in2/ft Check if As>As-min As-min=3(f,)1'2/f y.x (bw d) = 0.26 in2/ft>0.01 in2/ft Use As= 0.26 in2/ft As.m,n=200(b,,)(d)!fy=0.34 in2/ft> 0.26 in2/ft As=0.34 in2/ft Reinforcement Try No 4 @ 6.00 in., Abar=0.196 sq.in. Provided, As_proy=Aba.(12 in/ft)/spacing =0.196(12)/6.000=0.393 in2/ft Compute a and check if fs= fyand if tension controls a =A,s_provfyl(.85fr b,t,)= 0.393(60000)/[0.85(2500)(2.20)] = 5.040 in. a Id= 5.040/8.500 =0.593 ab/d= 0.582, Table A-4 - Compute Check if tension controls a/d,= a/d= 0.593 (one layer) ato,/dt=0.319, Table A-4- Compute Mn=4[As-prov fy(d-a/2)]/12 = 0.90(0.393)(60000)[8.50 -5.04/2]= 10568 ft-lb/ft (4) Mn= 10568 ft-lb/ft) > (Mu= 367 ft-Ib/ft) OK Check development Lb l db= fya 13 oA I [25(f,)112] Ld/db= 60000(1.00)(1.00)(1.00)/[25(2500)1/2]=48.00 Lb=48.00(0.50) = 24.00 in. 1.2 Design stair lattice support Design loads: This structure does not support a hand rail and its intent to keep the occupant from going thru the 3 x 3 boards. Per ASCE 7-16, Point load = 200 lb or 50 lb/ft @ the critical span location CUSTOM DESIGN & ENGINEERING, INC. October 20, 2021 Page 13/ 17 Copyright©2021 Custom Design&Engineering,Inc.All rights reserved.