基于全过程分析的土石混合体变形破裂宏-细观机理及尺度效应研究

项目名称： 基于全过程分析的土石混合体变形破裂宏-细观机理及尺度效应研究

项目编号： No.51479095

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 水利工程

项目作者： 徐文杰

作者单位： 清华大学

项目金额： 84万元

中文摘要： 由于土石混合体自身固有的复杂特性及现有试验有段的限制，很难通过现场及室内试验直接获取其物理力学特性参数，这一直困扰着许多重大工程建设。本项目以新的视角和研究思想，紧紧围绕土石混合体特殊的结构性特征为核心，建立典型土石混合体细观结构及内部块石三维形态信息数据库,阐明其规律性，实现不同成因、不同结构、不同尺度的土石混合体三维精细结构建模，形成数字土石混合体研究体系。基于三轴试验及CT三维实时扫描，开展土石混合体宏-细力学特性及尺度效应力学试验研究。基于三维重建及数字体相关技术，发展三维离散场数字体相关理论，研发颗粒材料三维全场动态变形分析系统，实现试样全场颗粒及细观结构演变全过程定量分析。基于颗粒离散元高性能计算及连续-非连续耦合方法，实现复杂条件下土石混合体破裂过程数值试验研究，协同物理力学试验从全过程揭示土石混合体变形破裂宏-细观机理及尺度效应，提出合理的力学试验方法及表征单元尺度。

中文关键词： 土石混合体；力学特性；数值试验；破坏机理；尺度效应

英文摘要： For the complexity of soil-rock mixture (S-RM) and the limitation of the testing methods, it is very difficult or impossible to directly study the physical and mechanical characteristics of S-RM using in-situ or laboratory test. S-RM always perplex many important engineering projects. With new viewpoints and research thoughts, this work will take the structural characteristics of S-RM as the kernel, build the information database of the meso-structures and three dimensional geometric shape of internal rock blocks of the typical S-RM, describe their regularity and relationship with the geological formation, realize the fine-structure model building of S-RM with different meso-structure and different scale, and form the study system of digital S-RM. Based on triaxial tests and real-time scanning technique of CT, the macro-meso mechanics and scale effect of S-RM will be studied in this work. And based on the 3D reconstruction and 3D discrete volume correlation (DVC) theory, a 3D discrete-DVC technique and a software name as DVC-Particle3D will be developed to realize the quantitative analysis of developing process of particles and meso-structure of S-RM sample in the process of the test. Using high performance computing and continuous-discontinuous coupling techniques to perform the numerical tests of S-RM under complex conditions, and cooperates with the mechanical test to reveal the deformation and failure mechanisms of S-RM in the whole process of the test at macro-meso scale and scale effect, and provide the reasonable mechanical test method and representative elementary volume (REV) scale of S-RM.

英文关键词： Soil-rock mixture;Mechanical behavior;Numerical test;Failure mechanism;Scale effect