裂隙几何特征对岩体力学特性的模拟试验研究  

Simulation experiment study on the influence of fracture geometric features on mechanical properties of rock mass

作　　者：白杰 袁超[2] BAI Jie;YUAN Chao(China Railway 20th Bureau Group Co.,Ltd.,Xi'an 710016,China;College of Architecture and Civil Engineering,Xi'an University of Science and Technology,Xi'an 710054,China)

机构地区：[1]中铁二十局集团有限公司,陕西西安710016 [2]西安科技大学建筑与土木工程学院,陕西西安710054

出　　处：《煤矿安全》2023年第7期188-195,共8页Safety in Coal Mines

基　　金：陕西省教育厅专项基金资助项目(19JK0521)。

摘　　要：为探究裂隙结构面对岩体力学特性的影响,对含预制裂隙岩样进行压缩模拟试验,基于SEM、NMR、Vic-3D技术,结合声学及宏细观结构特征对岩体进行多尺度研究,重点分析裂隙几何特征对岩体力学性状与行为的演变规律。结果表明:岩样强度随裂隙长度、贯穿度及数量的增加呈现下降趋势,随裂隙倾角的增大呈现先减小后增大的趋势,30 mm裂隙岩样强度最低,90°裂隙岩样强度最为接近完整岩样;完整岩样、0°、90°裂隙岩样发生张拉破坏,不同裂隙贯穿度岩样发生拉剪复合型破坏,不同裂隙长度、数量、30°、45°及60°裂隙岩样均表现为剪切破坏。岩样受荷后微小孔隙比重降低,大中孔隙比重增大,表明预制裂隙造成的初始损伤和荷载作用均能改变岩样内部孔隙结构,进而影响其宏观力学特性。To explore the influence of fracture structure on mechanical properties of rock mass,compression simulation experiment were carried out on rock samples with prefabricated fractures.Based on SEM,NMR and Vic-3D technology,multi-scale study was carried out on rock mass in combination with acoustic and macro-meso-structural characteristics.The rock sample strength decreases with the increase of fracture length,penetration and number,and decreases first and then increases with the increase of fracture dip angle.The rock sample strength of 30 mm fracture is the lowest,and the rock sample strength of 90°fracture is closest to the intact rock sample.Tensile failure occurred in intact rock samples,0°and 90°fracture samples and tensile and shear composite failure occurred in rock samples with different fracture penetration degrees.Shear failure occurred in rock samples with different fracture lengths,numbers,30°,45°and 60°fractures.After loading,the proportion of micro pores decreases while that of medium and large pores increases,indicating that the initial damage and loading caused by prefabricated fractures can change the internal pore structure of rock samples,thus affecting its macroscopic mechanical properties.

关 键 词：岩体 预制裂隙 几何特征 力学特性 模拟试验 

分 类 号：TD315[矿业工程—矿井建设]