脆性岩体在不同围压下卸载的岩爆特性  

The Burst Properties of Brittle Rock under Different Confining Pressure Unloading Conditions

作　　者：吝曼卿[1,2] 张电吉[1] 倪小山[2] 习本军 涂力[1] 

机构地区：[1]武汉工程大学资源与土木工程学院,湖北武汉430073 [2]湖北兴发化工集团股份有限公司,湖北宜昌443700

出　　处：《金属矿山》2017年第6期28-33,共6页Metal Mine

基　　金：国家自然科学基金项目(编号:51504167;51474159);湖北省重大科技创新项目(编号:2016ACA178);武汉工程大学基金项目(编号:K201407)

摘　　要：岩爆是高地应力环境下开挖扰动的一种地质灾害。通过对类岩体大尺寸试件进行不同围压下的顶部梯度加载—单面卸载的加卸荷试验,采集试件内部测点在岩爆前后的应变过程,结合岩爆岩体的宏观破坏现象,分析脆性岩体在不同围压加卸载条件下的岩爆特性。研究表明:不同围压下进行加卸载试验时,试件卸载时的围压大小会直接影响岩体在岩爆时的破坏形态;试件在2种加载路径下发生岩爆时,卸载面产生的岩爆起裂点均是由卸载面中部的拉伸破坏,进而由卸载面上、下处岩体的压缩破坏引起的;试件在高围压环境下产生岩爆瞬间,内测点的垂直应变变化值大于其在低围压环境下的变化值,试件在高围压加卸载路径下产生的岩体岩爆烈度相对较大。Rock burst is a geological disaster under high stress environment excavation. Unloading test is done under different confining pressures loading and gradient on top loading-unloading on one sided by the large size of rock specimens. The strain of each measuring point inside of the test specimen is collected,combing with the macroscopic damage phenomenons of rock burst,the rock burst properties of brittle rock under different confining pressure unloading conditions is analyzed. The test results show that： the failure model of brittle rock after rock burst is affected directly by the different confining pressures caused by specimen unloading test; the initiation critical crack point during the rock burst process located in specimen unloading surface is caused by the tensile failure of the middle of specimen unloading surface firstly,then caused by the rock compression failure of the upper and lower of specimen unloading surface; the vertical strain value of the specimen point under the high confining pressure environment is larger than the value under the low confining pressure environment at the rock burst transient;the specimen rock burst intensity caused under high confining pressure loading and unloading path is relatively large.

关 键 词：脆性岩体 卸载围压 应力梯度 岩爆特性 

分 类 号：TD315[矿业工程—矿井建设]