基于PFC^(2D)颗粒流模拟的青砂岩冲击破裂能耗特性定量化表征  

Quantitative Characterization of Energy Consumption Characteristics for Impact Fracture of Green Sandstone Based on PFC^(2D)Particle Flow Simulation

作　　者：赵环帅 潘永泰[1,2] 乔鑫 余超 曹行健[1,2] 李凯宁 ZHAO Huan-shuai;PAN Yong-tai;QIAO Xin;YU Chao;CAO Xing-jian;LI Kai-ning(School of Chemical and Environmental Engineering,China University of Mining and Technology(Beijing),Beijing 100083,China;Engineering Research Center for Mining and Urban Solid Waste Recycling,China University of Mining and Technology(Beijing),Beijing 100083,China)

机构地区：[1]中国矿业大学(北京)化学与环境工程学院,北京100083 [2]中国矿业大学(北京)矿山与城市固废资源化工程研究中心,北京100083

出　　处：《地球科学与环境学报》2024年第6期832-842,共11页Journal of Earth Sciences and Environment

基　　金：国家自然科学基金项目(52074308)。

摘　　要：冲击载荷效应影响着岩体的稳定性,目前研究主要集中于岩石宏观破裂特征及能量演化规律,且大多属于定性研究,缺乏细观层面定量化表征。结合室内试验与细观参数标定,建立了青砂岩宏观-细观力学响应关系,分析了青砂岩在不同瞬时冲击速率下的破裂特点、裂纹数量、断裂时间与能量利用效率。结果表明:青砂岩破裂特征可分为局部、扩展及加剧破坏模式,裂纹扩展规律呈底部萌生、X状共轭斜面、密集扩展模式,裂纹扩展时间由快速增加逐渐趋于平缓,平均值为275μs;青砂岩能量利用效率分为缓慢增加、快速增加及稳定增加阶段,最大能量利用效率为10.851%;同时,通过拟合得到青砂岩破裂微单元数量、总裂纹数量、裂纹生成时间及能量利用效率与瞬时冲击速率的定量化关系。研究结果可为岩石破碎工艺参数合理选择提供指导。The impact loading affects the stability of rock mass.Currently,research of rocks mainly focuses on the characteristics of macro failure and laws of energy evolution,and most of them belong to qualitative research,lacking quantitative characterization at the microscopic level.In order to deeply study quantitative characterization of energy consumption characteristics for impact fracture of green sandstone,the macro-micro relationship of mechanical response in green sandstone was established by combining the laboratory tests and microscopic parameter calibration,and the fracture characteristics,crack number,fracture time and utilization efficiency of energy in green sandstone were analyzed under different instantaneous impact rates.The results show that the fracture characteristics of green sandstone can be divided into localized,extended and intensified fracture modes;the crack extension pattern of the green sandstone presents bottom initiation,X-shaped conjugate ramp,and intensive extension modes;the crack extension time changes from rapid increase to gradually slow down,and the average value is 275μs;the utilization efficiency of fracture energy in green sandstone is divided into the stages of slow increasing,rapid increasing and stable increasing,with the maximum utilization efficiency of fracture energy 10.851%.At the same time,the quantitative relationship between the number of destructive micro-unit,the total number,the generation time of cracks,utilization efficiency of fracture energy and the instantaneous impact rate of green sandstone was obtained through fitting.The research results can provide reference for the reasonable selection of parameters in the crushing process of rock.

关 键 词：岩石力学 青砂岩 颗粒流模拟 冲击载荷 断裂能 瞬时冲击速率 能量利用效率 

分 类 号：TU452[建筑科学—岩土工程]