黏滞性软土的固结模型及软基长期变形计算

项目名称： 黏滞性软土的固结模型及软基长期变形计算

项目编号： No.41472279

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 地质学

项目作者： 陈晓平

作者单位： 暨南大学

项目金额： 82万元

中文摘要： 软土受力变形过程既包括基于固结原理的压密过程也包括基于黏滞特性的蠕变过程，两者相互影响，共同控制着软基的长期变形和稳定。申请者的前期研究表明：蠕变固结的耦合效应与土的渗透性和排水边界条件密切相关；蠕变作用可以被固结作用弱化。本项目拟综合利用试验、理论推导和数值模拟等手段更深入研究非线性黏滞性土体的固结特性。关键科学问题：1）一维压密状态下瞬时变形条件和排水距离对初始似弹性固结阶段的影响机制及正常固结阶段的一致性应力-应变-应变率关系；2）三轴剪切状态下考虑了不同排水条件的体积蠕变或兼具体积蠕变和剪切蠕变特性的蠕应变率变化规律； 3）基于经典固结理论的蠕变固结模型和软土地基长期变形及稳定性的简化计算方法。根据研究进一步揭示软土变形过程中蠕变与固结的耦合机制，提出黏滞性软土的固结模型和蠕变参数的确定方法，为固结理论的完善和实际工程的分析计算提供理论依据和技术支持。

中文关键词： 岩土力学；相互作用；岩土工程；本构模型

英文摘要： The deformation of soft soil under effective stress consists of two parts. The first part is compression, produced by consolidation phenomenon, and the second part is creep, in response to the viscosity. They are interrelated, and both control the long-term deformation and stability of soft foundation. Our previous studies show that the coupling effect of consolidation and creep is closely related to permeability of soil and drainage boundary conditions, and the creep properties can be weakened by the consolidation effect.By means of laboratory experiments, theoretical derivation and numerical simulation and so on, the consolidation behavior of soils exhibiting nonlinear viscosity are investigated in this project. The key scientific problems are that: 1) the influence mechanism of instantaneous deformation condition and drainage distance on the initial elastic-like stage of consolidation before yielding, and the unique relationship of effective stress-viscous strain-viscous strain rate after yielding under one-dimensional consolidation state; 2) the creep strain-rate variation that behaves as bulk creep or both bulk creep and shear creep characteristics considering the drainage conditions under triaxial shear state; 3)the coupled model of consolidation and creep based on classic consolidation theory, and a simplified calculation method of long-term deformation and stability of soft foundation. According to the research, this project will further reveal the coupling mechanism of creep and consolidation, and propose the consolidation model of soils exhibiting viscosity and the methods for determining creep parameters. This project will provide the fundamental theory and well as technical support for the practical engineering calculation.

英文关键词： geotechnicalmechanics;interaction;geotechnique;constitutive modeling