- 地下建筑工程课程设计解析与实例
- 唐兴荣编著
- 432字
- 2021-10-27 16:33:13
3.2.4 标准管片配筋计算
以标准管片(B)为例来说明管片的配筋计算方法。
1. 截面内力确定
由表3-6可见,在126°时轴力最大和弯矩最大,M=-157.939kN·m,N=1001.376kN。衬砌管片同时受到较大的正弯矩和负弯矩,采用对称配筋。简化模型b=1000mm,h=350mm,取as==50mm。根据修正惯用法中的η-ξ法,由于纵缝接头的存在而导致结构整体刚度降低,取圆环整体刚度EJz为:
![](https://epubservercos.yuewen.com/AE4759/21511157508182706/epubprivate/OEBPS/Images/72_03.jpg?sign=1734424566-OQSLYAS5iP1Ys45r3wJ62n4ly81yZsFp-0-eb4a3955f16f5a1ec3d6913c60ab0e76)
而管片的内力:
(1)最大负弯矩时
M b=(1+ξ)M=-(1+0.3)×157.939kN·m=-205.321kN·m,Nb=N=1001.376kN
(2)最大正弯矩时
M b=(1+ξ)M=(1+0.3)×75.174kN·m=97.726kN·m,Nb=N=846.690kN
2. 环向钢筋计算
(1)按最大负弯矩配筋 假定为大偏心受压构件:
![](https://epubservercos.yuewen.com/AE4759/21511157508182706/epubprivate/OEBPS/Images/73_01.jpg?sign=1734424566-0n02MIxiNnm1IVISHAZMGGDYxrsWpaPd-0-2669cc8973de6d0122581a2efb11206b)
对称配筋,as==50mm,h0=h-as=(350-50)mm=300mm
C50,fc=23.1MPa,α1=1.0
HRB335级,=300MPa
![](https://epubservercos.yuewen.com/AE4759/21511157508182706/epubprivate/OEBPS/Images/73_04.jpg?sign=1734424566-19WgTNZSLoTodV7JEca4K1iwwokoV4aG-0-e2301a4be0985129a72b381d28d5895a)
取x==100mm,并向受压钢筋合力点取矩得
![](https://epubservercos.yuewen.com/AE4759/21511157508182706/epubprivate/OEBPS/Images/73_06.jpg?sign=1734424566-MyX78K3XejcFxsec8fyOgN6lP8pXem4J-0-09054230aa5275816d4f5c45dcf5dbb3)
选配
(2)按最大正弯矩配筋 假设为大偏心受压构件:
![](https://epubservercos.yuewen.com/AE4759/21511157508182706/epubprivate/OEBPS/Images/73_08.jpg?sign=1734424566-oepvObogtDvgZP0dSV7WYlilRin8a6b1-0-b59879b92a9b8cb20fdff3dcb0d49914)
对称配筋,as==50mm,h0=h-as=(350-50)mm=300mm
C50,fc=23.1MPa,α1=1.0
HRB335级,=300MPa
![](https://epubservercos.yuewen.com/AE4759/21511157508182706/epubprivate/OEBPS/Images/73_11.jpg?sign=1734424566-PYMaZDuFLussjgC0px6RPaZ9jHz2J2ze-0-b924c5cdabf24c108952bdaf811dc0dd)
取x==100mm,并向受压钢筋合力点取矩得
![](https://epubservercos.yuewen.com/AE4759/21511157508182706/epubprivate/OEBPS/Images/73_13.jpg?sign=1734424566-Vd63gH67alctDMtF4vhCdXgGBxXW3mMZ-0-88580c4d6a11f7c50bdcd15e6cf761e5)
取As==600mm2
选配
综上计算表明,为安全起见,按最大负弯矩配筋。
(3)环向弯矩平面承载力验算(按轴心受压验算)
![](https://epubservercos.yuewen.com/AE4759/21511157508182706/epubprivate/OEBPS/Images/74_01.jpg?sign=1734424566-TSScjlyEgi7SVGbXQWgOXAefLQgiemt2-0-1dce7d6316159e9ad56705e6da876785)
查《混凝土结构设计规范》(GB 50010—2010)(2015年版)表6.2.15,可得轴心受压构件的稳定系数φ(按线性插入计算)
![](https://epubservercos.yuewen.com/AE4759/21511157508182706/epubprivate/OEBPS/Images/74_02.jpg?sign=1734424566-vN4pszVhEZnhCwdeGY38P960pettcow2-0-11de4421b20297ed440f95092ecf5c0b)