考虑体变与大变形时高应力砂性土扩孔问题能量分析方法比较  

COMPARISON OF ENERGY DISSIPATION ANALYTICAL METHODS FOR CAVITY EXPANSION CONSIDERING LARGE DEFORMATION AND VOLUMETRIC CHANGE IN SAND SOIL UNDER HIGH STRESSES

作　　者：邹金锋[1] 罗强[1] 李亮[1] 杨小礼[1] 赵炼恒[1] 但汉成[1] 

机构地区：[1]中南大学土木建筑学院,湖南长沙410075

出　　处：《岩石力学与工程学报》2008年第2期426-432,共7页Chinese Journal of Rock Mechanics and Engineering

基　　金：国家自然科学基金资助项目(50408020);教育部新世纪优秀人才计划基金资助项目(05-0686)

摘　　要：根据圆孔扩张过程中塑性区土体在孔扩压力作用下的应力–应变–体变关系、扩孔过程中的能量守恒原理、非相关联流动准则以及莫尔–库仑破坏准则,分别给出考虑体变守恒和大变形规律2种条件下砂性土圆孔扩张问题的极限扩孔压力计算公式。实测结果与2种理论结算结果的对比分析表明:考虑大变形时的理论成果与实际情况更加吻合,因此该方法具有一定的工程应用价值,可以用于砂性土的极限扩孔压力预估。而且,由于剪胀的影响,砂性土的极限扩孔压力与剪切模量和剪胀系数的总体关系是非线性的先减后增关系。According to Mohr-Coulomb failure criteriont,he stress-strain-volume change relationshipst,he volume balance and energy conservation equations,and the rules of large deformation and non-associated flow under high stresses,the limit bearing capacities of cavity expansion are given considering the large deformation and dilation with volumetric change and large deformation,respectively.The developed theory considering the large deformation agrees with the results of in-situ test,which can give reasonable results than those of theory considering the volumetric change.Furthermore,as for the influence of the dilation,the limit expansion pressure has nonlinear relationship with the dilation and the shear modulus in sand soil.

关 键 词：土力学 能量耗散 能量守恒 大变形 体变 圆孔扩张 

分 类 号：TU44[建筑科学—岩土工程] O241[建筑科学—土工工程]