顶管矩形工作井复合式后背墙反力分布研究

Reaction distribution investigation and structural analysis of composite thrust wall of rectangular pipe jacking shaft

顶管工作井在顶进施工过程中受力复杂,主要表现在:确定千斤顶推力在内部结构、围护结构和后背墙外侧土体之间的作用力是如何传递,土体变形对墙背土体抗力发挥的影响以及其对结构内力计算分析的影响。对现有顶管工作井计算方法进行归纳基础上,通过对工程算例建立数值计算模型,求证了后背墙各部分反力在宽度和深度方向上的分布规律,为探求一种合理简化更加接近实际的顶管复合式后背墙结构计算方法提供参照。

The thrust wall is a very important component of rectangular shaft; its stress and strain are both fairly complex when it suffered the thrust of pipe jacking. How to make certain the thrust force, which is transmitted from internal lining of working shaft to external soil mass, is quite significant; how much will the soil pre-deformation affect, and these results directly affect the calculation accuracy of retaining structure and internal lining of working shaft. By using numerical modeling analysis method, the thrust force transmission pattern is found; and the reaction distribution in the depth and width direction of the thrust wall is calculated; then the internal forces of each components of the thrust wall are ascertained on the basis of known reaction distribution analysis. This paper offers references for calculating pipe jacking thrust wall according to rational simplification and approximate hypothesis.