先求最大剪力 FA= 300X2.5/4=187.5 kN V=187.5 kN<0.25βcfcbh0=594.3 kN
Vcs= 187.5=1.75/(λ+1)ftbh0+fyvAsv/sh0 h0=700-35=665 λ=1500/665=2.26
ft=1.43N/mm^2 b=250mm fyv=270N/mm^2 可以求出Asv/s=0.334
Ф8 Asv1=50.3mm^2 s=50.3X2/0.334=301 双肢箍 取s=200
Ф10 Asv1=78.5mm^2 s=78.5X2/0.334=470 即箍筋采用Ф8@200
验算最小配箍率 ρsv=2X50.3/200/250=0.2012%>0.24ft/fyv=0.24X1.43/270=0.127%