考虑时间效应的超固结非饱和土弹黏塑性本构模型及其验证  

Elastic-viscoplastic constitutive model for overconsolidated unsaturated soils considering time effects and its verification

作　　者：苏彦林 蔡国庆[1,2] 刘祎[1,2] 单冶鹏 李舰 SU Yanlin;CAI Guoqing;LIU Yi;SHAN Yepeng;LI Jian(Key Laboratory of Urban Underground Engineering of Ministry of Education,Beijing Jiaotong University,Beijing 100044,China;School of Civil Engineering,Beijing Jiaotong University,Beijing 100044,China)

机构地区：[1]北京交通大学城市地下工程教育部重点实验室,北京100044 [2]北京交通大学土木建筑工程学院,北京100044

出　　处：《岩土工程学报》2023年第6期1250-1258,共9页Chinese Journal of Geotechnical Engineering

基　　金：国家自然科学基金项目(U2034204,52078031);北京市自然科学基金(8202038);中央高校基本科研业务费项目(2020JBM048,2020CZ002,2021YJS122)。

摘　　要：时间效应对超固结非饱和土的力学和变形特性影响较大,建立考虑时间效应的超固结非饱和土弹黏塑性本构模型,对于准确分析超固结非饱和土时间相依变形特性具有重要意义。以超固结土统一硬化模型为基础框架,建立了一个同时考虑固结度、基质吸力、时间效应的超固结非饱和土弹黏塑性本构模型。首先,根据超固结土弹塑性变形特性,引入统一硬化参数对一维弹黏塑性本构模型进行修正,建立了连续加载条件下超固结土弹黏塑性本构模型;其次,采用非饱和土巴塞罗那模型屈服面,结合过应力理论,建立了考虑时间效应和基质吸力影响的弹黏塑性模型。与巴塞罗那模型相比,额外引入了与时间效应相关的黏滞系数。模型验证和试验数据对比结果表明,该模型能够合理地预测超固结非饱和土时间相依变形特性。The time effects have a significant influence on the deformation characteristics of the overconsolidated unsaturated soils.Establishing an elastic-viscoplastic constitutive model for the overconsolidated unsaturated soils considering the time effects is of great significance for accurately analyzing the time-dependent deformation characteristics.Based on the unified hardening model for the overconsolidated soils,an elasto-viscoplastic constitutive model for the overconsolidated unsaturated soils is established,considering the degree of consolidation,matric suction and time effects.Firstly,according to the elasto-plastic deformation characteristics of the overconsolidated soils,the one-dimensional elasto-viscoplastic constitutive model for the overconsolidated soils under continuous loading condition is modified by introducing the unified hardening parameters.Secondly,by using the Barcelona model yield surface of the unsaturated soils and based on the over-stress theory,an elasto-viscoplastic model considering the time effects and the influences of suction is established.Compared with the Barcelona model,an additional viscosity coefficient related to the time effects is introduced.The comparative results of model verification and experimental data show that the proposed model can reasonably predict the time-dependent deformation characteristics of the overconsolidated unsaturated soils.

关 键 词：超固结 非饱和土 基质吸力 时间效应 过应力理论 弹黏塑性 

分 类 号：TU43[建筑科学—岩土工程]