The cross section of a narrow-gage railway bridge is shown in part (a) of the figure. The bridge is constructed with longitudinal steel girders that support the wood cross ties. The girders are restrained against lateral buckling by diagonal bracing, as indicated by the dashed lines. The spacing of the girders is s1 = 55 in. and the spacing of the rails is s2 = 30 in. The load transmitted by each rail to a single tie is P = 1,600 lb. The cross section of a tie, shown in part (b) of the figure, has width b = 5.0 in. and depth d. Steel rail Wood tie Steel girder (b) (a) Determine the minimum value of d based upon an allowable bending stress of 1,525 psi in the wood tie. (Disregard the weight of the tie itself.). Round your answer to one decimal place. dmin in.

Rigid beam ABC is supported by a pinned connection at C and by an inclined strut that is pin-connected at B and D as shown. The strut is fabricated from two steel [E = 200 GPa] bars, which are each d= 77 mm wide and b = 17 mm thick. Between B and D, the bars are separated and connected by two spacer blocks, which are s= 30 mm thick. Assume that LAB = 0.75 m, LBc = 1.85 m, LcD = 1.60 m, P = 70 kN, The strut cross section is also shown. Determine (a) the compression force in strut BD that is created by the loads acting on the rigid beam. (b) the slenderness ratios for the strut about its strong and weak axes. (c) the minimum factor of safety in the strut with respect to buckling. P A Answers: (a) FBD = (b) (L/r) horz = LCD (L/r) vert = (c) FS= LAB B spacer blocks 150.43 110.041 i 498.471 i 0.138 LBC (1) kN D Spacer block b S b

This is one question. Please answer all parts and doesn’t break honor code!