粗粒土边界面塑性模型及其积分算法  

Bounding surface plasticity model for granular soil and its integration algorithm

作　　者：孙增春 汪成贵 刘汉龙[1,2,3] 尹振宇 吴焕然 肖杨[1,2,3] SUN Zeng-chun;WANG Cheng-gui;LIU Han-long;YIN Zhen-yu;WU Huan-ran;XIAO Yang(School of Civil Engineering,Chongqing University,Chongqing 400045,China;Key Laboratory of New Technology for Construction of Cities in Mountain Area,Chongqing University,Chongqing 400045,China;National Joint Engineering Research Center of Geohazards Prevention in the Reservoir Areas,Chongqing University,Chongqing 400045,China;Department of Civil and Environmental Engineering,The HongKong Polytechnic University,HongKong,China)

机构地区：[1]重庆大学土木工程学院,重庆400045 [2]重庆大学山地城镇建设与新技术教育部重点实验室,重庆400045 [3]重庆大学库区环境地质灾害防治国家地方联合工程研究中心,重庆400045 [4]香港理工大学土木与环境工程学系,中国香港

出　　处：《岩土力学》2020年第12期3957-3967,共11页Rock and Soil Mechanics

基　　金：国家自然科学基金(No.51922024,No.51678094);重庆市自然科学基金(No.cstc2019jcyjjqX0014)。

摘　　要：粗粒土的强度、变形特性对土石坝、边坡和路基等工程的安全性与稳定性有着至关重要的影响。针对粗粒土在复杂应力状态下的强度和变形特性,在边界面塑性理论和临界状态理论框架下,通过引入状态参数和动态临界状态线建立了粗粒土状态相关边界面塑性模型。模型不仅能够模拟粗粒土的应变硬化和体积收缩行为,还能描述应变软化和体积膨胀特性。基于ABAQUS的二次开发平台,结合带误差控制的改进欧拉积分算法编写了边界面塑性模型的UMAT子程序。通过设置不同的应变增量步和误差容许值,对改进欧拉积分算法的精确性和收敛性进行了分析。对不同密实状态和围压下粗粒土三轴排水剪切试验进行了模拟,验证了带误差控制的改进欧拉积分算法应用于粗粒土边界面塑性模型的合理性,为进一步工程应用奠定了基础。The strength and deformation behavior of granular soil have an important influence on the safety and stability of earth-rock dams, slopes and subgrade. For the strength and deformation behavior of granular soil under complex stress state, a state-dependent bounding surface plasticity model was established for granular soil by incorporating the state parameter and dynamic critical state line in the framework of the bounding surface plasticity theory and the critical state theory. The established model can not only predict the strain hardening and volumetric contraction, but also well describe the strain softening and volumetric expansion behaviors. Based on the secondary development platform of ABAQUS, the UMAT subroutine of the bounding surface plasticity model was developed by using the modified Euler integration algorithm with error control. The accuracy and convergence of the modified Euler integration algorithm were analyzed with different strain increments and integration error tolerance values. Finally, the rationality of the modified Euler integration algorithm with error control applied to the bounding surface plasticity model was verified by simulating the triaxial drained shear tests of granular soil under different densities and pressures, which laid a foundation for further engineering application.

关 键 词：粗粒土 边界面 状态相关 改进欧拉积分算法 UMAT 

分 类 号：TU431[建筑科学—岩土工程]