Question

Find the capacity of the column Pr. Assume Fy = 50 ksi. Column is braced laterally in all directions at the mid-height. (0) Draw the buckled shape of column. (ii) Find the recommended design K value. (iii) What is the unbraced length of column (iv) Find the capacity of column (W) Can the column support a loading of DL-300kips, LL-400kips Hint: Pn uses resistance factor . Use the appropriate design method (LRFD or ASD). You can use the design tables provided at the end of the exam. LRFD Load Combinations to consider: U= 1.2D+1.6L U= 1.4D Rotation prevented, free to translate (move laterally, similar to top end support of Q1.2-d) W14X99

Answer 1

station - Fy= 50 ksi Rotation prevented wjux loft 9 Buckled shape of columns in recommended is values pin- fixed 2) =) K= 0.8 k=10 pin-pin

2) The unbraced length of column :- K Top = 0.8x 10 = 8ft I bottom = 1.0x 10 = loft Since top < Kbottom. Unbranced length is governed by bottom. k = loft W Capacity of column i ate both using the table for fy= soksi , k = loft een = 1210 Kips PL = 3ookips, LL=400 kips Pu=1-20L4 1.6LL z 1.2309)+ 1.6(400) = loookins Pucoen column can carry the load.