Question

A column in a 2-story building supports loads from the second floor and the roof. Loads were calculated and are provided below: Roof Dead = 18,000 pounds Roof Live = 14,400 pounds Wind (down) = 36,000 pounds Wind (up) = 60,000 pounds Floor Dead - 32,000 pounds Floor Live - 39,000 pounds. Using applicable ASD load combinations (refer to Ch. 2 of your textbook), determine the following: a. The maximum axial compression load in pounds for the column supporting the roof level. b. The maximum axial tension load in pounds for the column supporting the roof level C. The maximum axial compression load in pounds for the column supporting the 2 floor and roof level

Answer 1

a) & b) Dead Load, 18 kips D 0 kips Floor Live Load, 14.4 kips Roof Live Load, Snow Load, 0 kips O kips S Rain Load, R Wind Load (down) (up) 36 kips W 60 kips 0 kips Earthquake Load, E LOAD COMBINATIONS - ASD 18 kips D D+L 180 18 kips = D+(Lr or S or R) 18 14 32.4 kips 180.75 0) D+0.75L+0.75(Lr or S or R) 0.75 14) 28.8 kips 1 21.6) D+(0.6W or 0.7E) 18 39.6 kips 1 36.0) D-(0.6W or 0.7E) 18 -18 kips D+0.75(0.6W or 0.7E)+0.75 L+0.75 (Lr or S or R) 0.75 0)0.75 14) 18 0.75 21.6 45 kips + + D-0.75(0.6W or 0.7E)+0.75 L+0.75 (Lr or S or R) 0.75 0) + 0.75 14) 0.7536.0) + 1.8 kips 18) 32.4 kips 36) 0.6D+0.6W 0.6 0.6 + 18) -25.2 kips 0.6D-0.6W 0.6 0.6 60 18) 10.8 kips 0.6D+0.7E 0.6 0.7 18) 0.7 10.8 kips 0.6D-0.7E 0) 0.6 45 kips (Maximum axial compression) (Maximum axial tension) DESIGN LOAD 25.2 kips

c) Dead Load, (=18+32] 50 kips D - Floor Live Load, Roof Live Load, 39 kips - 14.4 kips L, = Snow Load, Rain Load, 0 kips 0 kips R 36 kips Wind Load, (down) W - 60 kips (up) 0 kips Earthquake Load, E = LOAD COMBINATIONS- ASD 50 kips D - D+L 5039 89 kips = D+(Lr or S or R) 5014 64.4 kips = D+0.75L+0.75(Lr or S or R) 500.75 39) 0.75 14) =90.05 kips D+(0.6W or 0.7E) 121.6) 50 = 71.6 kips = D-(0.6W or 0.7E) 136.0) 50 14 kips D+0.75(0.6W or 0.7E)+0.75 L+0.75 (Lr or S or R) 0.75 14) 50 0.7521.6) 0.7539) + 106.3 kips D-0.75(0.6W or 0.7E)+0.75L+0.75(Lr or S or R) 50 0.75 63.05 kips 0.75 39) + 0.75 14) 36.0) + 36) 50) 0.6D+0.6W 0.6 0.6 + 51.6 kips 50) -6 kips 0.6 0.6D-0.6W 0.6 60) = 0.6 50) 30 kips 0.7 0 ) 0.6D+0.7E 0.6 0) 0.6D-0.7E 50) 0.7

30 kips (Maximum) 106.3 kips DESIGN LOAD = 6 kips (Minimum)