一个描述软黏土时效特性的一维弹黏塑性模型

发布时间：2018-02-21 00:55

本文关键词： 软黏土弹黏塑性模型时效特性固结蠕变应变率效应应力松弛　出处：《岩土力学》2016年08期 　论文类型：期刊论文

【摘要】：为了描述软黏土一维应力-应变关系的时效特性,基于Bjerrum的等时间线体系,提出等黏塑性应变率线概念,推导了黏塑性应变率与黏塑性应变增量的关系,建立了软黏土的一维弹黏塑性模型;从理论上分析了新建模型与3种典型的一维弹黏塑性时效本构模型的内在联系,表明新建模型与其他3种模型在本质上是等效的,且形式更简洁,物理意义更明确;利用新建模型对软黏土的固结-蠕变耦合效应、应变率效应、应力松弛效应等时效特性进行了理论分析,并得到了相应的解析解;结合宁波软黏土的一维固结试验,阐述了模型参数的确定方法,并用新建模型对宁波软黏土的固结-蠕变试验、温州软黏土的一维多级等应变率试验、香港海相软黏土的一维应力松弛试验进行模拟,验证了新建模型的有效性。研究结果表明,新建模型能很好地模拟软黏土的一维时效特性。
[Abstract]:In order to describe the aging characteristics of one-dimensional stress-strain relationship in soft clay, the concept of iso-viscoplastic strain rate line is proposed based on Bjerrum's iso-time line system, and the relationship between viscoplastic strain rate and viscoplastic strain increment is derived. The one-dimensional elastic-viscoplastic model of soft clay is established, and the intrinsic relationship between the new model and three typical one-dimensional elastic-viscoplastic aging constitutive models is theoretically analyzed, which shows that the new model is essentially equivalent to the other three models. The new model is used to analyze the aging characteristics of soft clay, such as the coupling effect of consolidation and creep, strain rate effect, stress relaxation effect and so on, and the corresponding analytical solution is obtained. Based on the one-dimensional consolidation test of Ningbo soft clay, the determination method of model parameters is expounded. The consolidation creep test of Ningbo soft clay and the one-dimensional multistage iso-strain rate test of Wenzhou soft clay are carried out by using the new model. The one-dimensional stress relaxation test of Hong Kong marine soft clay proves the validity of the new model. The results show that the new model can well simulate the one-dimensional aging characteristics of the soft clay.
【作者单位】：中国科学院武汉岩土力学研究所岩土力学与工程国家重点实验室;武汉市市政建设集团有限公司;
【基金】：中国科学院重点部署项目、百人计划项目(No.KZZD-EW-TZ-12) 国家重点基础研究发展计划(973)项目(No.2015CB057905) 国家自然科学基金重大研究计划集成项目(No.91215301)~~
【分类号】：TU447

【相似文献】