某受均布荷载矩形截面简支梁,b*h=300*700(mm^2) Mmax=300KN·m ,Vmax=320KN,砼C35,纵向受力筋HRB400,箍筋HPB300,as=70mm(纵向受力筋布两排),求纵筋及箍筋数量在考试 来个简洁点的可以吗
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![某受均布荷载矩形截面简支梁,b*h=300*700(mm^2) Mmax=300KN·m ,Vmax=320KN,砼C35,纵向受力筋HRB400,箍筋HPB300,as=70mm(纵向受力筋布两排),求纵筋及箍筋数量在考试 来个简洁点的可以吗](/uploads/image/z/1475381-29-1.jpg?t=%E6%9F%90%E5%8F%97%E5%9D%87%E5%B8%83%E8%8D%B7%E8%BD%BD%E7%9F%A9%E5%BD%A2%E6%88%AA%E9%9D%A2%E7%AE%80%E6%94%AF%E6%A2%81%2Cb%2Ah%3D300%EF%BC%8A700%EF%BC%88mm%5E2%EF%BC%89+Mmax%3D300KN%C2%B7m+%2CVmax%3D320KN%2C%E7%A0%BCC35%2C%E7%BA%B5%E5%90%91%E5%8F%97%E5%8A%9B%E7%AD%8BHRB400%2C%E7%AE%8D%E7%AD%8BHPB300%2Cas%3D70mm%EF%BC%88%E7%BA%B5%E5%90%91%E5%8F%97%E5%8A%9B%E7%AD%8B%E5%B8%83%E4%B8%A4%E6%8E%92%EF%BC%89%2C%E6%B1%82%E7%BA%B5%E7%AD%8B%E5%8F%8A%E7%AE%8D%E7%AD%8B%E6%95%B0%E9%87%8F%E5%9C%A8%E8%80%83%E8%AF%95+%E6%9D%A5%E4%B8%AA%E7%AE%80%E6%B4%81%E7%82%B9%E7%9A%84%E5%8F%AF%E4%BB%A5%E5%90%97)
某受均布荷载矩形截面简支梁,b*h=300*700(mm^2) Mmax=300KN·m ,Vmax=320KN,砼C35,纵向受力筋HRB400,箍筋HPB300,as=70mm(纵向受力筋布两排),求纵筋及箍筋数量在考试 来个简洁点的可以吗
某受均布荷载矩形截面简支梁,b*h=300*700(mm^2) Mmax=300KN·m ,Vmax=320KN,砼C35,纵向受力筋HRB400,箍筋HPB300,as=70mm(纵向受力筋布两排),求纵筋及箍筋数量
在考试 来个简洁点的可以吗
某受均布荷载矩形截面简支梁,b*h=300*700(mm^2) Mmax=300KN·m ,Vmax=320KN,砼C35,纵向受力筋HRB400,箍筋HPB300,as=70mm(纵向受力筋布两排),求纵筋及箍筋数量在考试 来个简洁点的可以吗
1.正截面受弯配筋计算
ξb = β1 / [1 + fy / (Es·εcu)]= 0.8/[1+360/(200000*0.0033)] = 0.518
x = h0 - [h02 - 2M / (α1·fc·b)]0.5 = 630-(6302-2*300000000/1/16.72/300)0.5
= 103mm ≤ ξb·h0 = 0.518*630 = 326mm
As = α1·fc·b·x / fy = 1*16.72*300*103/360 = 1441mm2
ξ = x / h0 = 103/630 = 0.164 ≤ 0.518
配筋率 ρ = As / (b·h0) = 1441/(300*630) = 0.76%
最小配筋率 ρmin = Max{0.20%,0.45ft/fy} = Max{0.20%,0.20%} = 0.20%
As,min = b·h·ρmin = 420mm2
取6C18,As =1527mm2
2 斜截面承载力计算
0.7·ft·b·h0 = 0.7*1575*0.3*0.63 = 208.3kN < V = 320.0kN
当 V > 0.7·ft·b·h0、500 < h ≤ 800mm 构造要求:
最小配箍面积 Asv,min = (0.24·ft / fyv)·b·s = (0.24*1.575/270)*300*200 = 84mm2
箍筋最小直径 Dmin = 6mm,箍筋最大间距 smax = 250mm
一般受弯构件,其斜截面受剪承载力按下列公式计算:
V ≤ αcv·ft·b·h0 + fyv·Asv/s·h0
Asv = (V - 0.7·ft·b·h0)·s / (fyv·h0) = (320000-0.7*1.575*300*630)*200/(270*630)
= 131mm2
矩形截面受弯构件,其受剪截面应符合下式条件:hw = h0 = 630mm,
当 hw/b ≤ 4 时,V ≤ 0.25·βc·fc·b·h0
Rv = 0.25·βc·fc·b·h0 = 0.25*1*16720*0.3*0.63
= 790.0kN ≥ V = 320.0kN,满足要求.
Asv = 131mm2,箍筋取A6@250