Q3. The W250 × 45 A-36 steel column is pinned at its top and fixed at its base. Also, the column is braced along its weak axis at mid height. If P= 250 kN, investigate whether the column is adequate to support this loading. Use F.S. = 2.0 against buckling and F.S. 1.5 against yielding. Assume rx = 112 mm, A = 5700 mm², Ix = 71.1 × 10° mm4, Iy = %3D 7.03 × 10° mm*, cx = 113 mm and yield stress capacity is 250 MPa. (Ans: max. Pallow= 299.7 kN) P 4 250 mm 250 mm 4 m 4 m

Situation 2. A W14x90 of A992 steel is used as a pin-connected column. The 30ft long column is braced at mid-height with respect to its weak axis. Determine the axial compressive load. (ASD & LRFD) 30ft Properties of W14x90: 15ft 15ft A = 26.5 in.² d = 14.0 in. by = 14.5 in. t₁ = 0.710 in. tw = 0.440 in. Tx = 6.14 in. ry = 3.70 in. by/2t, = 10.2 h/tw = 25.9

Two L4 × 3 × -in. steel angles are welded together to form the column AB. An axial load P of magnitude 16 kips is applied at point D. Using the allowable-stress method, determine the largest allowable length L. Use Øy= 36 ksi and E= 29 × 106 psi. (Round the final answer to two decimal places.) m100 B 3 in. D in. 3 in. 4 in. The largest allowable length L is 184.63 x ft.