中文摘要：

文章采用两阶段法和数值模拟方法的分析结果,验证了应用整体数值模拟方法研究隧道开挖对邻近群桩的影响是可靠的。借助有限差分数值软件,通过采用Mohr-Coulomb弹塑性屈服准则,建立三维数值模型,研究了砂性土中不同应力释放率、不同桩间距、不同桩长情况下群桩遮拦效应的变化规律。分析结果表明：隧道开挖时的应力释放对群桩的遮拦效应影响不大;除桩体沉降以外,群桩的遮拦效应系数曲线基本上随桩间距的增大而逐渐减小;群桩桩长差异的变化对群桩遮拦效应的影响情况比较复杂,不同指标在不同桩长情况下的变化规律呈现出一定的不协调性。

英文摘要：

This paper proves that the application of a numerical simulation method is reliable for studying the influ- ence of tunnel excavation on an adjacent pile group by comparision of the two-phase method and numerical simula- tion method. Based on the Mohr-Coulomb e established with the finite difference numeri lastic-plastic yield criterion, a three-dimensional numerical model was cal analysis software to study the variation law of the shiehting effect of a pile group under different stress release rates, pile spacings and pile lengths. The analysis results show that the stress release caused By tunnelling has little influence on the shiehting effect; the curves of the pile group shielding effect coefficient decrease with the increase of pile spacing except for the pile settlement; the influence of pile length difference on the shielding effect is more complicated, because the variation of various indexes does not ex- hibits the same law with changing of the pile length.