软黏土蠕变特性试验研究:回顾与发展  

Experimental investigation on creep behavior of soft clays:Review and development

作　　者：尹振宇[1] 朱启银[1] 朱俊高[2] 

机构地区：[1]上海交通大学土木工程系,上海200240 [2]河海大学岩土工程研究所,南京210098

出　　处：《岩土力学》2013年第S2期1-17,共17页Rock and Soil Mechanics

基　　金：国家自然科学基金资助(No.41240024);欧盟玛丽居里行动计划资助(No.PIAPP-GA-2011-286397);高等学校博士学科点专项科研基金资助(No.20110073120012);上海市浦江人才计划项目资助(No.11PJ1405700)

摘　　要：大量的室内和现场试验表明软黏土存在长期变形难以收敛的问题,为了更深入地认识软黏土的蠕变特性,首先,从微观物理化学角度探讨蠕变机制;然后,深入分析一维应力条件下次固结系数的演变规律以及确定方法和三轴排水、不排水蠕变特性及黏土的长期抗剪强度、室内旁压试验和现场试验等复杂应力下的黏土蠕变特性等,并且讨论黏土蠕变特性与应变速率和应变松弛特性在一维和三轴条件下的关联性;最后,从黏土次固结特性与微观结构的相关性、如何准确描述次固结系数的非线性及蠕变过程中应力剪胀剪缩关系发展等三方面更深入地探讨软黏土蠕变特性。Extensive laboratory tests and field observations show that soft clay exhibits long-term deformation.For further understanding of the creep characteristics of soft clay,the mechanism of creep is first discussed from the microscopic physicochemical viewpoint.Then,the evolution of second compression coefficient and its determination under 1D condition,triaxial creep characteristics under drained and undrained conditions,long-term shear strength,and the creep characteristics under complex stress conditions are analyzed.The relevance of creep characteristics to strain-rate and strain relaxation characteristics under both 1D and 3D conditions is discussed.Finally,some new development of the creep characteristics of soft clay are presented in three aspects:the relevance of second compression coefficient to microstructure,accurate description of nonlinear creep,and the stress-dilatancy during drained and undrained creep.

关 键 词：软黏土 蠕变 次固结 应力剪胀 微观结构 

分 类 号：TU411[建筑科学—岩土工程]