written 8.5 years ago by | • modified 4.0 years ago |
The beam is reinforced with $6$ Nos. $25$mm dia. an tension fau. Design the shear reinforcement using vertical stirrups.
written 8.5 years ago by | • modified 4.0 years ago |
The beam is reinforced with $6$ Nos. $25$mm dia. an tension fau. Design the shear reinforcement using vertical stirrups.
written 8.5 years ago by | • modified 8.5 years ago |
$$b=230 mm , d=600 mm ,l=10m, d_c=50 mm , Ast=6-25mm$$
$ =2946mm^2\\ D=d+d_c=650mm \\ self \space ast=(0.23\times0.65)\times 23= 3.73 kn/m$
factored shear force $(V_{UD} )= 1.5 x v \\ = 1.5 x 192.41 \\ = 288.61KNm \\ Z_{uv}=\dfrac {V_{UD}}{b\times d}=\dfrac {288.6\times10^3}{230\times600}=1.92 N/mm^2 \lt 2.8 N/mm^2 \therefore safe \\ pt= \dfrac {100Ast}{b\times d}=\dfrac {100\times6\times491}{230\times 600}=2.13 \% $
shear stress in concrete $(Z_{uc} )$
$$Z_{uc} =0.8N/mm^2$$
$ V_{uc} = Z_{uc}bd= 0.8\times 230\times 600=110.4KN\\ V_{u\space min} =0.4bd=0.4\times 230\times 600=55.2 KN\\ V_{uc}+V_{u\space min}=110.4+55.2=165.6KN \\ \therefore V_{UD} \gt V_{uc}+V_{u\space min}$
Hence design & provide shear reinforcement.
$$V_{us}=V_{uD}-V_{uc}=288.61-110.6=178.21 KN\ \phi^2=10 mm $$ Assume $$a_{sv}=2\times \dfrac \pi4 \times 10^2=157mm^2$$ Spacing:- $$S_1=\dfrac {0.87f_ya_{sv}d}{V_{us}}$$ $ S_1=\dfrac {0.87\times 415\times 157\times 600}{178.21\times 10^3}=190.84\\ S_2=0.75d=0.75\times 600=450mm \\ S_3=300 mm$
Hence $10$ mm $\phi2$ strumps at $v$ mm c/c