ISSN 1000-3665 CN 11-2202/P

    基坑开挖过程中埋地管线沉降位移解析计算

    Analytical computation of settlement displacement of buried pipeline caused by excavation

    • 摘要: 基坑开挖会诱发邻近埋地管线产生沉降变形,获取管线变形量对评估管线的正常使用和安全具有重要意义。基于弹性地基梁理论,建立地下管线沉降位移的计算公式,并分析地表中心沉降量和计算长度对管线沉降位移的影响;根据埋地管线与基坑边缘的几何关系,将计算长度取值依据界定为5种工况;通过与两个标定算例对比,验证解析方法的合理性;以北京某基坑工程为例,分析管线沉降位移的时空变化规律。研究结果表明:不同时期的沉降位移计算值和实测值变化趋势一致,但计算值略高于实测值;地表中心沉降量对管线沉降位移影响显著,输入值越大,沉降曲线形状越“凹”,输入值越小,沉降曲线越平缓;管线沉降位移自中心点向两端降低速率依次增加,在边界点附近降低速率减小,范围约为计算长度的1/10。所提方法在管线沉降预估方面偏于保守,是现有埋地管线沉降理论的一个补充,可为施工前期预判管线沉降分布提供重要参考依据。

       

      Abstract: Excavation can induce the settlement deformation of adjacent buried pipeline. Obtaining the deformation is of great significance for evaluating the normal use and safety of pipeline. In this study, based on the elastic foundation beam theory, the calculation formula of the settlement displacement of buried pipeline is derived, and the influence of the two parameters of the surface center settlement and the calculation length on the settlement displacement of pipelines is emphatically analyzed. According to the geometric relationship between the buried pipeline and the edge of the foundation pit, the calculation length can be used to divide into five working conditions. The rationality of the analytical method is verified by comparing with two cases. In the case of excavation in Beijing, the spatio-temporal variation rules of settlement displacement of buried pipeline were analyzed. The results show that the variated trend of the calculated settlement displacement in different periods is consistent with that from measurement, but the calculated value is slightly higher than the measured value. The surface center settlement has a significant influence on the pipeline settlement displacement. larger input causes more concave settlement curve, and smaller input leads to smoother settlement curve. The decreasing rate of settlement displacement increases from the central point to end, and decreases near the boundary point, with the range of about one tenth of the calculated length. The proposed method in this study is conservative in the evaluation of pipeline settlement, which is a supplement to the existing settlement calculation theory of buried pipelines, and can provide a important information for predicting the distribution of pipeline settlement in the early stage of construction.

       

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