Question

Perform the following structural analysis on the 60-ft. pedestrian walkway deck truss and floor system. Assume only service loads (no load factors or impact).

(Stringer Calculations – Pedestrian Loading)

1.      Calculate all dead and live loads.

2.      Calculate the maximum reactions for the exterior and interior stringers.

3.      Develop the shear and moment diagrams for the exterior and interior stringers.

-o ?? 12" (w) o (A CONCRETE CaRB wizxs T? 12'-0 Trensses 2-0 AL MEmBes Teuss MemBERS ARE MADE 1 ASTm AnD9 GRaDE SD STEEL. E: 29000 K3

Answer 1

"Dead load (a) Railing: - 15 p/f (b) Concrete curb: - equivalent point load => 12""(N) times 10"" (H) times 145 pcf = 121 p/f (c) slab: - UDl from slab = 7"" times 145 times 1' [per unit ] p/f = 84.5 p/ft \r\n Live load: - As per AASTHO LRFO design manual 3.6.1.6 Pedestrian load = 0.075 KsF 2. Load distribution: - P_1 = Load from railing = 15 p P_2 = Load from pedestal = (concrete curb) = 12 p P_3 = Dead load of slab = 84.5 p/ft P_4 = live load per AASTHO = 75 p/ft R_1 = reaction on external stringer R_2 = reaction on internal stringer. R_1 = P_1 + P_2 + 1/2 times (P_3 + P_4) times L_1 = (15 + 12) + 1/2 times (84.5 + 75) times 4 = 455 p R_2 = 1/2 (P_2 + P_3) times (L_1 + L_2) = 1/2 times(84.5 + 75) times 8"