Pasternak地基上基坑开挖对邻近地下管线影响的解析分析

Analytical analysis of the impact on adjacent underground pipelines due to foundation pit excavation on the Pasternak foundation

随着基建规模的扩大,基坑开挖引起周边地下管线变形问题仍需重点关注。首先计算基坑开挖对邻近管线产生的附加应力,然后基于Pasternak弹性地基梁模型,采用两阶段方法建立地下管线竖向位移平衡微分方程,利用有限差分法求解得到形式简洁的矩阵解析解,并把理论计算结果与两个工程实例监测数据进行比较。结果表明:本文计算结果与现场实测的地下管线变形规律基本一致,验证了该方法的合理性和准确性。计算模型概念简单,结果简洁明确,可作为分析和预测基坑开挖对邻近地下管线影响的一种新手段。

The deformation of the surrounding underground pipelines caused by the foundation pit excavation needs to be paid more attention to when the scale of infrastructure continues to expand nowadays.First,additional stress on adjacent pipelines caused by foundation excavation was calculated.Then the equilibrium differential equation of vertical displacement of underground pipeline was established using two-stage method based on the Pasternak foundation model,and the finite difference method was used to obtain the matrix analytical solution in the most concise form.Finally,the theoretical calculation results were compared with the monitoring data recorded in the two engineering cases.It shows that the calculation results almost matched the monitoring deformation law of underground pipelines,which validated the feasibility and accuracy of this method.The calculation model,which is high in accessibility of the concept and also concise and explicit when referring to the calculation result,may be implemented as a new method to analyze and predict the impact of foundation pit excavation on adjacent underground pipelines.