陆凤池1，  叶海桃2

(1南京金宸建筑设计有限公司，南京210019; 2长江南京航道工程局，南京210011)

 

[摘要] 顶管工程中，由于顶力的作用具有间歇性和短暂性，且被动土压力所需的位移量远大于主动土压力所需的位移量，因此后背土体被压实至剪切破坏时，前壁土体与井壁会产生短暂性脱空，从而在计算沉井水平承载力时可以不考虑前壁主动土压力的作用，仅考虑井底、井侧摩阻力和后背土压力的作用。根据井壁后背土体剪切破坏条件，推导出了后背土压力计算公式。从该公式可以看出，圆形沉井后背土体径向土压力增量按正弦函数形式分布。通过算例分析可知，本文计算方法是可行的。

[关键词] 顶管；沉井；土反力；顶力；水平承载力

中图分类号：TU753.4    文献标识码：A  文章编号：1002-848X(2012) S2-0523-04

 

Lu Fengchi1, Ye Haitao2

(1 Nanjing Kingdom Architecture Design Co., Ltd., Nanjing 210019, China; 2 Nanjing Changjiang Waterway Engineering Bureau, Nanjing 210011, China)

 

Abstract: Jacking force is intermittent and transient in pipe jacking engineering, and the displacement of the maximum passive earth pressure is much greater than the active earth pressure'. Therefore, when the soil of the back wall of sinking well is shear failure,  the soil of front wall will be separated from the sinking well. The horizontal bearing capacity of sinking well is consist of bottom friction, lateral wall friction and passive earth pressure of back wall without active earth pressure of front wall. The formula of earth pressure was derived according to shear failure of the soil of the back wall. It shows that the radial earth pressure mcrement of back wall is distributed on circular sinking well by sinusoidal function form. The method of this paper is feasible by the analysis of a case.

Keywords: pipe jacking; sinking well; earth counterforce; jacking force; horizontal bearing capacity