基于离散-连续耦合法的埋地管道受荷过程模拟分析

为了从宏、细观角度反映出埋地管道管周土体的承载特点,文章采用离散-连续界面耦合数值模型对埋地管道受荷过程进行模拟分析,其中管周填土采用离散单元法进行模拟,埋地管道及原状土基采用有限差分单元法进行模拟。结果表明:随着荷载或埋深的增大,管顶受压产生压缩变形,管顶土体发生“压力拱效应”,引起管周土压力重分布;耦合模型水平位移场显示埋地管道在受荷过程中管侧回填土及原状土基能够分担和转移外荷载;管周土体的细观接触力链分布形态与管顶土压力的分布规律形成相互印证。

To represent the bearing and force transmission features of the surrounding soil of buried pipeline from the macro and meso view, the numerical model of discrete-continuous interface coupling is applied to simulating and analyzing the loading process of buried pipeline. The backfill around the buried pipeline is simulated by the discrete element method, and the buried pipeline and the undisturbed soil foundation are simulated by the finite difference element method. The results show that as the load or burial depth increases, the top of the pipeline is compressed and deformed. The soil on the top of the pipeline is subjected to the pressure arch effect, which causes a redistribution of soil pressure around the pipeline. The distribution of the horizontal displacement shows that the buried pipeline transfers the external loads between the backfill and the undisturbed soil foundation during the loading process. The distribution of the contact force chain of the soil around the pipeline has a good agreement with that of the soil pressure on the top of the pipeline.