超固结黏土中不排水柱孔扩张弹塑性解及应用  

ELASTOPLASTIC SOLUTION AND APPLICATION OF UNDRAINED CYLINDRICAL CAVITY EXPANSION IN OVERCONSOLIDATED CLAY

作　　者：吕桂阳 和西良 梁汝鸣 付艳斌 刘洋 葛序尧 祝人杰 张波 LYU Gui-yang;HE Xi-liang;LIANG Ru-ming;FU Yan-bin;LIU Yang;GE Xu-yao;ZHU Ren-jie;ZHANG Bo(The Second Construction Limited Company of China Construction Eighth Engineering Division Design and Research Institute,Jinan,Shandong 250014,China;College of Civil and Transportation Engineering,Shenzhen University,Shenzhen 518060,China;Key Laboratory of Coastal Urban Resilient Infrastructures(MOE),Shenzhen University,Shenzhen 518060,China)

机构地区：[1]中建八局第二建设有限公司设计研究院,山东济南250014 [2]深圳大学土木与交通工程学院,深圳518060 [3]深圳大学滨海城市韧性基础设施教育部重点实验室,深圳518060

出　　处：《工程力学》2024年第1期160-170,共11页Engineering Mechanics

基　　金：国家自然科学基金项目(52078304,51938008,52090084);广东省重点领域研发计划项目(2019B111108001,2022B0101070001);深圳市科技计划项目(20220525163716003,KQTD20200909113951005)。

摘　　要：为求得超固结黏土中考虑K0影响的柱孔不排水扩张精确解,该文基于黏土和砂土模型(CASM)屈服准则,采用经典的应力剪胀关系,充分考虑土体静止土压力参数K0和重度超固结比,运用非相关联流动法则进行应力空间转换,进而建立超固结黏土中考虑K0影响情况下柱孔不排水扩张问题的一阶偏微分方程组求解模型。根据弹塑性边界已知的应力和位移条件,通过数值求解方法确定柱孔扩张模型的精确解。对比修正剑桥模型(MCC)解,基于SMP准侧改进的修正剑桥模型(SMP-MCC)解及黏土和砂土统一硬化模型(CSUH)解进行参数分析表明:当土体OCR≤2时,该文方法较好地模拟土体单元屈服应力和破坏应力;当土体OCR>2时,该文方法克服了超固结黏土高估屈服应力和破坏应力;当K0由1.0变化到2.5时,归一化极限扩孔压力由5.4变化到3.2,归一化极限超静孔隙水压力由2.4变化到1.0。并通过现场实测数据验证了该文方法的实用性与正确性。To obtain an accurate solution for the undrained cylindrical cavity expansion in over-consolidated clay considering the influence of K0,this study uses the Clay and Sand Model(CASM)yield criterion,adopts the classic stress-dilatancy relationship,and fully considers the static soil pressure parameter K0 and the heavy over-consolidation ratio.The non-associated flow rule is used to transform the stress space,and then the solution model of first-order partial differential equations is established for the undrained cylindrical cavity expansion in the over-consolidated clay under the influence of K0.According to the known stress and displacement conditions of the elastoplastic boundary,the accurate solution of the cylindrical cavity expansion model is determined by a numerical solution method.Comparing the modified Cambridge model(MCC)solution,the Modified Cambridge model(SMP-MCC)solution based on SMP yields criterion and the solution of unified hardening model of clay and sand(CSUH),the parameter analysis show that:when the soil OCR≤2,the method proposed can simulate the yield stress and failure stress of the soil element well.When the soil OCR>2,this method overcomes the overestimation of yield stress and failure stress of over-consolidated clay.When K0 changes from 1.0 to 2.5,the normalized ultimate expansion pressure changes from 5.4 to 3.2;the normalized ultimate expansion excess pore water pressure changes from 2.4 to 1.0.And the practicality and correctness of this method are verified by field measured data.

关 键 词：岩土力学 柱孔扩张理论 本构模型 超固结黏土 非相关联流动法则 

分 类 号：TU431[建筑科学—岩土工程]