减小静压排桩贯入中挤土效应的三维模拟研究

Three-dimensional Simulation Study of Reducing the Compaction Effect Caused by Penetration of Static Pressure Row Piles

为研究静压排桩贯入对周边土体产生的挤土效应及受力特性,在研究了排桩贯入对埋地管道产生的应力及位移的基础上,采用大型通用有限元软件ABAQUS,建立了防挤槽和应力释放孔的排桩贯入对临近既有埋地管线的三维模型,通过有防挤槽、应力释放孔与无防挤槽、应力释放孔的管道相应截面上的应力及位移对比,采取不同孔径、不同孔间距、不同孔深,来研究应力释放孔的孔径、孔间距、孔深等因素在减小挤土效应效果方面的影响。研究结果表明:应力释放孔直径越大、孔越深、相邻两孔距离越近,减小桩体贯入对管道产生的应力和位移的幅度也越大;应力释放孔能否达到减小桩体贯入对管道产生应力的目的与相邻应力释放孔的距离有关,相邻两孔距离近时可以减小桩体贯入对管道产生的应力,而相邻两孔距离远时,反而增大桩体贯入对管道产生的应力。

In order to investigate the compaction effect caused by penetration of static pressure row piles on the surrounding soil and its mechanical characteristics,the stress and displacement of embedded pipelines were analyzed by adopting the finite element software of ABAQUS.A three-dimensional model was built to compare the stresses and displacements on the corresponding cross section of the pipeline with and without anti-extrusion groove and stress-relief hole.Under the former condition,the row piles of anti-extrusion groove and stress-relief hole are penetrated into the adjacent embedded pipeline.The effects of pore size,spacing and depth of stress relief holes on soil compaction effect were examined and the results showed that the larger the diameter of the stress relief hole,the deeper the hole and the closer the two adjacent holes are,eventually leading to larger stress and displacement of the pipe.Whether or not the stress relief hole can reduce the stress produced by pile penetration is related to the distance of adjacent stress relief holes,and the stress produced by pile penetration can be lowered when the distance of two adjacent holes is close.However,when the distance between the two holes is far away,the stress of the pipe caused by the penetration of the pile body conversely increases.