横向穿越滑坡段埋地管道应变响应特性研究*

为准确描述横向滑坡作用下管道非线性响应特征，采用非线性自适应网格技术建立横向穿越滑坡段埋地管道三维有限元模型，利用非线性接触模型表征管土之间、滑坡体与非滑坡体之间的相互作用，探究滑坡位移、埋深及壁厚对管道应变响应特性的影响规律。研究结果表明:随着滑坡位移增大，滑坡体与非滑坡体交界区域和管道位移最大区域两侧管道应变显著增大，易发生失效；结合应变失效判定准则分析，管道不发生失效的最大滑坡位移、最小管道壁厚及最大埋深，在本文算例中分别是0.36 m、9.50 mm、0.97 m。因此管道经过滑坡区时，可适当增大壁厚、减小埋深；滑坡发生后，应重点关注滑坡体与非滑坡体交界区域及管道位移最大区域两侧的变形情况。研究结果可为穿越横向滑坡管道的设计及安全运营提供一定参考。

Study on strain response characteristics of buried pipelines laterally crossing landslide section

In order to accurately describe the nonlinear response characteristics of pipelines under the action of lateral landslide,a three-dimensional finite element model of buried pipelines laterally crossing the landslide section was established by using the nonlinear adaptive mesh technology.The influence of landslide displacement,buried depth and wall thickness on the strain response characteristics of pipeline was explored by using the nonlinear contact model to represent the interaction between pipeline and soil,landslide body and non-landslide body.The results showed that the strain of pipelines on both sides of the junction area of landslide body and non-landslide body and the maximum displacement area of pipeline increased significantly,which was prone to failure.Combined with the strain failure criterion analysis,the maximum landslide displacement,the minimum wall thickness and the maximum buried depth of the pipeline without failure were 0.36 m,9.5 mm and 0.97 m respectively in the calculation example.Therefore,the wall thickness should be increased while the buried depth should be reduced when the pipeline crossed the landslide prone area.After the landslide,the attention should be paid to the deformation at the boundary between the landslide body and the non-landslide body and on both sides of the maximum displacement area of the pipeline.The results can provide some reference for the design and safe operation of pipeline laterally crossing the landslide.