考虑土体自重应力影响的抗滑桩三维土拱效应
吕韶全1,孙狂飙1,王少锋1,陈鑫2,曾俊源2

(1.安徽交通控股集团有限公司,安徽 合肥 230088; 2.中国地质大学(武汉)工程学院,湖北 武汉 430074)

土拱效应; 三向应力状态; 理论模型; 数值模拟; 模型试验

Three-dimensional soil arching effect considering the influence of soil gravity stress on anti-slide pile
LÜ Shaoquan1,SUN Kuangbiao1,WANG Shaofeng1,CHEN Xin2,ZENG Junyuan2

(1.Anhui Transportation Holding Group Co.,Ltd.,Hefei 230088,China; 2.Faculty of Engineering,China University of Geosciences,Wuhan 430074,China)

soil arching effect; three directional stress state; theoretical model; numerical simulation; model test

DOI: 10.15986/j.1006-7930.2021.04.007

备注

基于Prandtl-Reissner地基极限承载力理论,建立了一种新的土拱效应力学分析模型,改进了拱脚破坏面的假设.研究表明,自重应力是引起土拱效应破坏的主导因素,低于临界深度时土的剪胀效应破坏拱脚,高于临界深度时由于土的剪切破坏拱脚失效; 研究结果与ABAQUS有限元数值模拟及室内模型试验结果一致.在三维状态下,在距桩顶表面一定深度内,拱脚处土的竖向位移会破坏拱脚,土拱效应减弱,在此以下一定深度段为土拱效应形成的有利深度,有利深度段深度下自重应力对土拱的破坏起主导作用.研究提出了根据桩土摩擦系数求解拱脚破坏面的新思路,为抗滑桩抗力设计提供了理论借鉴.
Based on Prandtl-Reissner's theory of ultimate bearing capacity of foundation,a new mechanical analysis model of soil arch effect is established,and the assumption of failure surface of arch foot is improved. The research shows that the self-weight stress is the main factor that causes the soil arching effect failure. When the soil is below the critical depth,the arch foot is damaged by the soil's dilatancy effect,and when the soil is above the critical depth,the arch foot fails due to the shear damage of the soil. The results are consistent with the results of ABAQUS finite element numerical simulation and laboratory model test. In the three-dimensional state,within a certain depth from the surface of the pile top,the vertical displacement of the soil at the arch foot will destroy the arch foot,and the soil arch effect will be weakened. A certain depth below this will be the favorable depth formed by the soil arch effect,and the self-weight stress at the depth of the favorable depth will play a dominant role in the soil arch failure. A new idea is proposed to solve the failure surface of arch foot according to the friction coefficient of pile and soil,which provides a theoretical reference for the resistance design of anti-slide pile.