K_0固结饱和土柱孔扩张问题弹塑性分析  

Elastoplastic analysis of cylindrical cavity expansion in K_0 consolidated saturated soils

作　　者：刘时鹏[1,2,3] 施建勇[1,2] 雷国辉[1,2] 林海[1,2] 

机构地区：[1]河海大学岩土力学与堤坝工程教育部重点实验室,南京210098 [2]河海大学岩土工程科学研究所,南京210098 [3]华北水利水电学院,郑州450011

出　　处：《岩土力学》2013年第2期389-394,403,共7页Rock and Soil Mechanics

基　　金：国家自然科学基金面上项目(No.50878075)

摘　　要：采用K0固结各向异性土体本构模型,将柱孔扩张后周围土体分为弹性区和塑性区,根据柱孔扩张理论和边界条件,推导出K0固结状态下饱和天然土体柱孔扩张问题弹塑性区的应力、塑性区半径以及超孔隙水压力的理论解答。同时,通过算例与修正剑桥模型解答进行对比分析,结果表明,土的不同初始固结状态对柱孔扩张后孔周围的应力和超孔隙水压力产生很大影响,采用考虑K0固结诱发各向异性土体本构模型所得到的应力和超孔隙水压力解答大于修正剑桥模型的解答,但塑性区影响半径却明显小于后者。Based on the anisotropic K0 consolidated soil constitutive model,the soil around the cylindrical cavity is classified into elastic zone and plastic zone.According to the cylindrical cavity expansion theory and boundary conditions,the closed-form expressions for the total stresses,the plastic zone radius and the excess pore water pressure of the K0 consolidated saturated soils are obtained.Meanwhile,a comparative results between the anisotropic constitutive model and modified Cam-clay model indicate that the different initial consolidation conditions have great effect on the stresses and excess pore water pressure induced by the cylindrical cavity expansion;the stresses and excess pore water pressure calculated with the K0 consolidated soil constitutive model are obviously greater than those from the solutions based on the modified Cam-clay model;but the plastic zone radius shows a contrary tendency.

关 键 词：K0固结土体各向异性本构模型 柱孔扩张 塑性区半径 超固结比 超孔隙水压力 

分 类 号：TU411.3[建筑科学—岩土工程]