基于Kerr地基模型单井降水邻近管线变形计算方法

为了研究单井降水对邻近管线的影响，基于Kerr地基模型结合两阶段法提出了一种单井降水引起邻近管线竖向变形的计算方法。在第一阶段采用有效应力原理与Dupuit假定计算出降水引起邻近管线受到的附加应力，第二阶段将管线视作搁置在三参数Kerr地基上Euler-Bernoulli梁，以此模拟管线与土的相互作用进而推导出管线的竖向位移。通过与原位降水试验及Winkler模型的结果进行对比，验证了所提方法的准确性，并进一步分析了土体弹性模量、渗透系数、管-井间距以及水位降深变化对管线竖向位移的影响。分析结果表明：所采用的Kerr地基模型考虑了土体变形的连续性，相比Winkler地基模型更具优越性；土体渗透系数及管-井间距对管线变形影响较小，而土体弹性模量与降水井内水位降深影响较大；土体弹性模量减小、水位降深增大均导致管线变形明显增大，且易引起管线位移超过允许值，应针对相应因素采取防控措施。

Calculation method of pipeline deformation adjacent to single well dewatering based on the Kerr foundation model

To investigate the impact of single well precipitation on nearby pipelines, a calculation method of vertical displacement of adjacent pipeline caused by single well dewatering is proposed based on the Kerr foundation model and the two-stage method. In the first stage, the effective stress principle and Dupuit assumption are used to calculate the additional stress caused by dewatering in the adjacent pipeline. In the second stage, the pipeline is regarded as an Euler-Bernoulli beam resting on the three-parameter Kerr foundation to simulate the interaction between the pipeline and the soil and deduce the vertical displacement of the pipeline. The correctness of the proposed method is verified by comparing it with the results of the Winkler foundation model and the in-situ pumping test. The influences of the elastic modulus of soil, permeability coefficient, pipeline-well spacing, and water level drop depth on the vertical displacement of the pipeline are further analyzed. The analysis results show that the Kerr foundation model adopted in this paper considers the continuity of soil deformation and has more advantages than the Winkler foundation model. Soil permeability coefficient and pipeline-well spacing have little effect on pipeline deformation. However, the soil elastic modulus and the water level drop depth have a significant effect. The decrease of soil elastic modulus and the increase of water level decrease both lead to the apparent increase of pipeline deformation and easily cause pipeline displacement to exceed the allowable value. Therefore, prevention and control measures should be taken according to the corresponding factors.