深受弯构件计算书

深受弯构件计算书

项目名称_____________日期_____________

设计者_____________校对者_____________

一、基本资料：

1．依据规范：

《水工混凝土结构设计规范》(SL/T 191-96)

中国水利水电出版社《水工钢筋混凝土结构学》

2．荷载参数：

弯矩: M = 421.05kN·m

剪力: Q = 66.66kN

结构系数: γd = 1.20

3．几何尺寸参数：

截面宽度： b = 300 mm

截面高度：h = 3250 mm

计算跨度：l0 = 7980 mm

纵筋合力点至近边距离: as = 70.0mm

4．材料参数：

混凝土强度等级：C30

fc = 14.300N/mm2ftk = 2.010N/mm2ft = 1.430N/mm2

纵向钢筋抗拉强度设计值fy = 360.000N/mm2

水平分布钢筋抗拉强度设计值fyh = 310.000N/mm2

竖向箍筋抗拉强度设计值fyv = 310.000N/mm2

二、计算过程：

1．正截面受弯承载力计算：

当纵筋等级为二级时，截面纵筋最小配筋率ρmin = 0.15%

αs = γd*M*1000000.0/fc/b/h0/h0

= 1.2*421048000.0/14.30/300/3180/3180 = 0.012

ξ = 1.0-(1.0-2.0*αs)0.5 = 0.012

hdb = h-0.25*(h-h0)*(l0/h-1.0)

式中l0/h = 7980/3250 = 2.46

hdb = 3250-0.25*(3250-3180)*(2.46-1.0) = 3224.5mm

支座截面ξ d = (5.0-l0/h)*(0.14-0.08*ξ)+ξ

式中l0/h = 7980/3250 = 2.46

ξd = (5.0-2.46)*(0.12-0.06*0.012)+0.012 = 0.366

内力臂z = (1.0-0.5*ξd)*hdb

= (1.0-0.5*0.366)*3224.5 = 2635.1mm

纵筋计算面积As = γd*M*1.0e6/fy/z

= 1.20*421.048*1.0e6/360.0/2635.1 = 532.61mm2

配筋率ρ= As/b/hdb = 0.06% < ρmin = 0.15%

纵筋按构造配筋,As = ρmin*b*hd = 0.15%*300.0*3224.5 = 532.61mm2

实际采用配筋方案：2f18 实配：Ag = 508.94mmmm2

实际配筋率ρ=Ag/hdb/b = 0.053%

2．斜截面受剪承载力计算：

截面尺寸控制:

hds = h-1.0/3.0*(h-h0)*(l0/h-2.0)

式中l0/h = 7980/3250 = 2.46

hds = 3250-1.0/3.0*(3250-3180)*(2.46-2.0) = 3239.4mm

由于h/b = 3250/300 = 10.8 > 6.0

截面允许剪力Vu = 1.0/60.0/γd*(l0/h+7.0)*fc*b*hds

式中l0/h = 7980/3250 = 2.46

Vu = 1.0/60.0/1.20*(2.46+7.0)*14.3*300.0*3239.4

= 1825009.5N

由于Vu > 剪力设计值V = 66660.0N,故截面尺寸符合要求!

受剪承载力计算:

在分布荷载作用下,Vc = 1.0/60.0*(9.2-l0/h)*fc*b*hds

式中l0/h = 7980/3250 = 2.46

Vc = 1.0/60.0*(9.2-2.46)*14.3*300.0*3239.4

= 1562155.9N

截面配置2根直径8水平分布筋,Ash = 100.5mm2

水平分布筋竖直方向间距sv = 200mm

Vsh = 1.0/6.0*(5.0-l0/h)*fyh*Ash/sv*hds

式中l0/h = 7980/3250 = 2.46

Vsh = 1.0/60.0*(5.0-2.46)*310.0*100.5/200.0*3239.4

= 214073.8N

Vsv = γd*V*1000.0-Vc-Vsh

= 1.2*66.660*1000.0-1562155.9-214073.8 = -1696237.7N Vsv<0.0,取As/sh = ρsvmin*b = 0.30mm

竖向箍筋采用方案：2D8@300 实配：Asv/sv = 0.335