Abstract

For the sake of economic design and safety requirement, the prediction of active earth pressure on laggings between stabilising piles is of great significance. However, the nonlinear distribution of active earth pressure on laggings between piles cannot be accurately predicted by using the classical theory. In this study, a novel method of calculating active earth pressure on laggings between piles is proposed based on the differential flat element method. For validation, calculations of the active earth pressure by using the novel method as well as other methods have been compared against the experimental results, indicating that the proposed method considering soil arching effect can well predict the active earth pressure on laggings. Furthermore, parametric analyses are conducted to examine of the most effective means of the piles and lagging system. It is concluded that the decrease rate of total active force flattens out when internal friction angle is larger than a certain degree and the lagging clear span suggests to be 1.5 to 1.7 times of pile diameter to meet economic requirements. This method can provide a reasonable estimation of the active earth pressure on laggings in the design of supporting structures.

摘要

出于经济设计和安全要求，主动土压力对稳定桩间保温层的预测具有重要意义。然而，经典理论无法准确预测桩间保温层主动土压力的非线性分布。本文提出了一种基于微分平面元法计算桩间保温板主动土压力的新方法。为了验证，将使用新方法以及其他方法计算的主动土压力与试验结果进行了比较，表明所提出的考虑土拱效应的方法可以很好地预测滞后土的主动土压力。此外，进行参数分析以检查桩和包胶系统的最有效方法。得出的结论是当内摩擦角大于一定程度时，总作用力的减小率趋于平缓，滞后净跨宜取桩径的1.5～1.7倍，才能满足经济要求。该方法可以在支护结构设计中对滞后土的主动土压力进行合理估算。