岩块宏细观参数对垮落带岩体力学特性的影响  

Influence of Macro-Micro Parameters of Rock Block on Mechanical Properties of Rock Mass in Caving Zone

作　　者：林圆 唐建新[1,2] 袁芳[1,2] 孔令锐 李成[1,2] 王潇[1,2] 鲁思佳 LIN Yuan;TANG Jianxin;YUAN Fang;KONG Lingrui;LI Cheng;WANG Xiao;LU Sijia(State Key Laboratory of Coal Mine Disaster Dynamics and Control,Chongqing University,Chongqing 400044,China;School of Resources and Safety Engineering,Chongqing University,Chongqing 400044,China)

机构地区：[1]重庆大学煤矿灾害动力学与控制国家重点实验室,重庆400044 [2]重庆大学资源与安全学院,重庆400044

出　　处：《矿业研究与开发》2024年第1期73-81,共9页Mining Research and Development

基　　金：煤矿灾害动力学与控制国家重点实验室自主研发资助项目(2011DA105287—zd201903).

摘　　要：为研究岩块的宏细观参数对垮落带岩体力学特性的影响,采用现场试验方法对采空区岩芯试样进行侧限压缩试验;基于试验结果采用PFC3D数值模拟方法开展了工程尺度下垮落带压缩变形特性的数值模拟,分析了模型尺寸、岩块块度、碎胀系数和细观力学参数对垮落带岩体力学特性的影响;并采用量纲法分析得到了垮落带的线性应力应变本构关系。结果表明,岩芯试样加载曲线近似线性变化,试样应力应变曲线的斜率随岩芯总长度的增加而增大;垮落带的压缩量随模型径高比和碎胀系数的增大而增大,随岩块块度、有效模量的增大而减小,当模型直径与高度的比值大于3∶1后,模型尺寸对垮落带压缩变形特性影响显著减小;当岩块块度大于1.3m后,垮落带的压缩变形曲线由指数增加变为线性增加;碎胀系数低于2.0时,垮落带压缩变形曲线呈线性变化,高于2.0后,应力应变曲线呈指数变化,垮落带的孔隙压密特性逐渐增强。In order to study the influence of macro-micro parameters of rock block on the mechanical properties of rock mass in caving zone,field experiment method was used to carry out the confined compression test on the core samples in goaf.Based on the experimental results,PFC3D numerical simulation method was used to simulate the compression deformation characteristics of caving zone under engineering scale,the influences of model size,rock block size,crushing expansion coefficient and micro-mechanical parameters on the mechanical properties of rock mass in caving zone were analyzed.The linear stress-strain constitutive relation of caving zone was obtained by dimensional analysis.The results show that the loading curve of the core samples change approximately linearly,and the slope of the stress-strain curve increases with the increase of the total length of the core.The compression of caving zone increases with the increase of diameter-height ratio and crushing expansion coefficient,and decreases with the increase of block size and effective modulus.When the ratio of the diameter to the height of the model is greater than 3∶1,the influence of the model size on the compression deformation characteristics of the caving zone is significantly reduced.When the rock block size is greater than 1.3m,the compressive deformation curve of the caving zone changes from exponential increase to linear increase.When the crushing expansion coefficient is lower than 2.0,the compression deformation curve of the caving zone changes linearly.When it is higher than 2.0,the stress-strain curve changes exponentially,and the pore compaction characteristics of the caving zone gradually increase.

关 键 词：垮落带 宏细观参数 岩块块度 力学特性 量纲分析 

分 类 号：TD313[矿业工程—矿井建设]