Mumbai University > CIVIL > Sem 7 > Limit State Method

Marks: 10 M

Steps:

1. To find, the depth of Actual N.A.

   $C_u=T_u \\ 0.36f_ckbX_u=0.87{\times}f_y{\times}Ast \\ \therefore X_u=\frac{0.87f_yAst}{0.36f_ckb}$

   $X_{umax}$ = $0.53 d⟹For \ F_{e250} \\ 0.48 d⟹For \ F_{e415} \\ 0.46d⟹For \ F_{e500}$

• When $X_u \lt X_{umax}⟹$ Under reinforced

  use

  $M_u=T_u{\times}L_a \\ M_u=0.87f_yAst{\times}(d-0.42X_u) \\ OR \\ M_u=C_u{\times}L_a \\ M_u=0.36{\times}f_ck{\times}b{\times}X_u{\times}(d- X_u)$

  • When $X_u \gt X_{umax}⟹$ …