白砂岩试件初始损伤后再加载力学特性试验分析  

Experimental Analysis of Mechanical Properties of Reloading After Initial Damage of White Sandstone Specimens

作　　者：任恒 朱永建 王平[1,2,3,4] 余伟健 黄钟[1] Ren Heng;Zhu Yongjian;Wang Ping;Yu Weijian;Huang Zhong(School of Resources,Environment and Safety Engineering,Hunan University of Science and Technology,Xiangtan 411201,China;Work Safety Key Lab on Prevention and Control of Gas and Roof Disasters for Southern Goal Mines,Hunan University of Science and Technology,Xiangtan 411201,China;Hunan Provincial Key Laboratory of Safe Mining Techniques of Coal Mines,Hunan University of Science and Technology,Xiangtan 411201,China;Hunan Province Key Laboratory of Coal Resources Clean-utilization and Mine Environment Protection,Hunan University of Science and Technology,Xiangtan 411201,China)

机构地区：[1]湖南科技大学资源环境与安全工程学院,湖南湘潭411201 [2]湖南科技大学南方煤矿瓦斯与顶板灾害预防控制安全生产重点实验室,湖南湘潭411201 [3]湖南科技大学煤矿安全开采技术湖南省重点实验室,湖南湘潭411201 [4]湖南科技大学煤炭资源清洁利用与矿山环境保护湖南省重点实验室,湖南湘潭411201

出　　处：《矿业工程研究》2019年第1期23-29,共7页Mineral Engineering Research

基　　金：国家自然科学基金面上项目(51774130; 51804114);煤炭资源清洁利用与矿山环境保护湖南省重点实验室开放基金(962-E21703)

摘　　要：针对巷道开挖以及回采过程中围岩应力平衡-卸压二次平衡引起的巷道大变形问题,利用应变测试仪及红外热像仪对白砂岩三轴加载-卸载后单轴再加载的破坏过程进行监测.实验结果表明:试件单轴加载破坏形态与初始损伤程度有关,白砂岩三轴加载超过57.5%峰值强度后卸载,单轴再加载破坏形态发生了改变;岩石单轴加载过程中环向应变速率与岩石裂隙大小有关,裂隙越大,环向应变速率越大,反之,应变速率则越小;单轴再加载损伤后的岩石,存在张裂变形与剪切滑移变形,破坏时以剪切滑移为主.试件剪切破坏时滑移面温度急剧升高.Aiming at the problem of large deformation caused by stress balance-pressure relief-secondary balance of surrounding rock during tunnel excavation and mining,the failure process of white sandstone under triaxial loading-unloading and uniaxial reloading is monitored by strain tester and infrared thermal imager.The experimental results show that the failure modes of the specimens under uniaxial loading are related to the initial damage degree.When the triaxial loading exceeds the peak strength of 57.5%,the uniaxial re-loading failure modes will be changed.The circumferential strain rate is related to the size of the rock cracks during uniaxial loading.On the contrary,the strain rate is smaller,and the rock after uniaxial re-loading has tension crack deformation and shear slip deformation,and shear slip is the main failure mode.The temperature of the slip surface will be increased sharply during shear failure.

关 键 词：三轴加载-卸载 单轴再加载 损伤弱化 初始损伤 力学特性 

分 类 号：TD322[矿业工程—矿井建设]