饱和软黏土的ESF弹塑性模型及其验证  

ESF Elastoplastic Model for Saturated Soft Clay and Model Validation

作　　者：徐日庆[1,2] 俞天赐 吴明明 张岗平 鞠露莹 徐启良 XU Riqing;YU Tianci;WU Mingming;ZHANG Gangping;JU Luying;XU Qiliang(College of Civil Engineering and Architecture,Zhejiang University,Hangzhou 310058,China;Architectural Design and Research Institute of Zhejiang University Co.,Ltd.,Hangzhou 310013,China;Power China Huadong Engineering Co.,Ltd.,Hangzhou 311122,China;School of Civil Engineering and Architecture,Zhejiang University of Science and Technology,Hangzhou 310023,China)

机构地区：[1]浙江大学建筑工程学院,浙江杭州310058 [2]浙江大学建筑设计研究院有限公司,浙江杭州310013 [3]中国电建集团华东勘测设计研究院有限公司,浙江杭州311122 [4]浙江科技大学土木与建筑工程学院,浙江杭州310023

出　　处：《湖南大学学报(自然科学版)》2025年第3期151-160,共10页Journal of Hunan University:Natural Sciences

基　　金：浙江省重点研发计划资助项目(2019C03103)。

摘　　要：为描述饱和软黏土的强度变形特性并解决传统弹塑性模型中屈服面角点处塑性应变增量方向不够明确的问题,建立了一种饱和软黏土的蛋形屈服面弹塑性本构模型.首先,基于蛋形函数(ESF),采用相关联流动法则,以塑性体应变作为内变量,建立了饱和软黏土的ESF弹塑性模型.模型通过引入封闭光滑的蛋形屈服面,克服了传统屈服面的角点缺陷.通过调整蛋形形状控制参数,将屈服面灵活转化为包括子弹形、椭圆形在内的多种形式,体现了模型的可退化性及通用性.然后,开展了杭州地区饱和软黏土的应力路径三轴不排水剪切试验,分析了软黏土的力学特征,并据此研究了模型参数在不同围压下的稳定性;最后,编制隐式积分算法有限元程序,利用杭州地区饱和软黏土和相关文献中饱和高岭土在不同围压下的等压固结不排水三轴试验验证模型的有效性.对比结果表明:模型计算值与实测值吻合良好,说明该模型能够合理预测不同类型饱和软黏土的不排水剪切特性.An egg-shaped yield surface elastoplastic constitutive model suitable for saturated soft clay was proposed to describe the strength and deformation characteristics of saturated soft clay and overcome the defect that the direction of the plastic strain increments at the corner of the yield surface is insufficiently defined in the traditional elastoplastic model.Firstly,the ESF elastoplastic model was formulated based on the egg-shaped function(ESF),adopting the associated flow law and employing the plastic volumetric strain as the internal variable.By introducing a closed and smooth egg-shaped yield surface,the corner problem in the traditional yield surface form was avoided.Additionally,by adjusting the value of egg-shaped parameters,the yield surface was flexibly transformed into various forms,including bullet-shaped and elliptical forms,which reflected the dependability and universality of this model.Subsequently,the undrained stress path triaxial tests were conducted on Hangzhou saturated soft clay to investigate its mechanical characteristics.The acquired data were used to analyze the stability of the model parameters under different confining pressures.Furthermore,a comprehensive analysis of the mechanical characteristics of the soft clay was performed,and the method for determining the model parameters was clarified.Finally,the finite element program using an implicit integration algorithm was developed,and its effectiveness was demonstrated through triaxial tests conducted on Hangzhou saturated soft clay and saturated kaolin clay from relevant literature under undrained conditions.The results revealed a satisfactory agreement between the simulated and experimental data,indicating that the proposed model can reasonably describe the behavior of various types of saturated soft clay under undrained conditions.

关 键 词：饱和软黏土 蛋形屈服面 弹塑性本构模型 不排水三轴试验 有限元程序 

分 类 号：TU43[建筑科学—岩土工程]