基于热力学理论的超固结黏土边界面模型  

Thermodynamics-based bounding surface model for overconsolidated clay

作　　者：陈艳妮[1] 杨仲轩[1] 

机构地区：[1]浙江大学建筑工程学院,浙江杭州310058

出　　处：《岩土工程学报》2017年第3期547-553,共7页Chinese Journal of Geotechnical Engineering

基　　金：国家自然科学基金项目(51322809;51578499);浙江省教育厅项目(N20110091)

摘　　要：基于热力学理论和临界状态土力学的框架,建立了耗散应力空间内的α-β屈服面。定义耗散势和背应力为应力的函数来实现在真实应力空间非相关联流动。基于边界面模型框架,准确模拟了超固结黏土在初始屈服面内的弹塑性响应。采用临界状态线与边界面交点在静水压力轴上的投影为映射中心,并定义剪胀函数,保证了"干侧"发生剪胀,而"湿侧"发生剪缩。与Boston Blue Clay,Lower Cromer Till和London Clay 3种土在不排水条件下的三轴试验数据进行对比,验证了模型的合理性和有效性。Based on the framework of thermodynamics and critical state soil mechanics, a new α-β yield surface is formulated in the triaxial space. Based on the non-associated flow rule and bounding surface framework, the proposed model can simulate the correct elastoplastic responses within its initial yield surface for overconsolidated clay. By defining the dissipative function and back stress being functions of stress, the non-associated flow is naturally followed in the true stress space. The mapping center in the p-q space is selected as the projection on the hydrostatic axis of the intersection of critical state line and bounding surface, such that the contractive response on the ‘wet side＇ and dilative response on the ‘dry side＇ can be guaranteed if an appropriated dilatancy function is defined. Comparisons are made between the experimental data of three typical clays under undrained condition, and a full agreement indicates the simulative capability of the proposed model.

关 键 词：热力学理论 α-β屈服面 超固结黏土 临界状态 边界面模型框架 

分 类 号：TU43[建筑科学—岩土工程]