细观参数对冻结砂土局部应变特征的影响研究  

Study on the Influence of Microscopic Parameters on the Local Strain Characteristics of Frozen Sand

作　　者：周若星 姚晓亮 高雄 王文丽 余林 Zhou Ruoxing;Yao Xiaoliang;Gao Xiong;Wang Wenli;Yu Lin(School of Civil Engineering and Architecture,Xi'an University of Technology,Xi'an 710048,P.R.China;SCEGC NO.1 Construction Engineering Group Co.,Ltd.,Xi'an 710068,P.R.China)

机构地区：[1]西安理工大学土木建筑工程学院,西安710048 [2]陕西建工第一建设集团有限公司,西安710068

出　　处：《地下空间与工程学报》2025年第2期444-451,460,共9页Chinese Journal of Underground Space and Engineering

基　　金：国家自然科学基金(42272319);国家自然科学基金(42101132)。

摘　　要：冻土变形破坏过程与其局部应变特征发展规律有着密切联系,研究应变局部化发展规律有助于揭示其变形破坏机理,为实际工程提供理论依据。本文结合冻土平面应变试验结果及离散单元法,研究土体细观参数对其局部应变特征的影响。根据不同温度和应变速率条件下平面应变试验数据结果,采用“试错法”确定接触黏结模型在不同条件下的细观参数,结果表明:应力-应变曲线的峰值应力及其对应的轴向应变值基本一致,但在应变软化阶段,数值模拟结果相较于试验结果发展较快,这主要是由于接触黏结模型中不考虑土颗粒间胶结冰对转动的抵抗作用所致;剪切带的宽度、倾角及残余强度的试验和模拟值基本一致,结合库伦解的基本形式建立的细观摩擦系数与内摩擦角的量化关系能够准确描述土体的剪切带倾角,这表明细观参数中的摩擦系数是影响土体最终破坏形态的主要因素。The deformation and failure process of frozen soil is closely related to the development law of its local strain characteristics.Studying the law of strain localization helps to reveal its deformation and failure mechanism,providing more theoretical basis for practical engineering.This article combines the results of plane strain tests on frozen soil and the Discrete Element Method to study the influence of soil microscopic parameters on its local strain characteristics.Based on the results of plane strain test data under different temperature and strain rate conditions,the microscopic parameters of the linear contact bond model under different conditions are determined through the"trial and error method".Comparative analysis of experimental and numerical simulation results show that the peak stress and corresponding axial strain values of the macroscopic stress-strain curve are the same.Due to the fact that the interface of the linear contact bond model does not consider the resistance of frozen soil particles to rotation,the curve obtained by numerical simulation develops faster in the strain softening stage.The measured and simulated values of the width,inclination angle of the shear band and residual strength are basically consistent,indicating that the friction coefficient in the microscopic parameters is the main factor affecting the final failure form of the soil.By comparing the experimental and simulation results,it is further shown that the relationship between the friction coefficient and the internal friction angle can be described by establishing the quantitative relationship between the friction coefficient and the Shear band inclination angle in the basic form of Mohr-Coulomb solution.

关 键 词：离散单元法 接触黏结模型 应变局部化 应力-应变曲线 剪切带 

分 类 号：TU91[建筑科学—建筑理论]