Mesoscale fracture behavior of Longmaxi outcrop shale with different bedding angles:Experimental and numerical investigations

作     者：Jianping Zuo Jingfang Lu Rojin Ghandriz Jintao Wang Yanhong Li Xiaoyan Zhang Jun Li Hongtao Li Jianping Zuo;Jingfang Lu;Rojin Ghandriz;Jintao Wang;Yanhong Li;Xiaoyan Zhang;Jun Li;Hongtao Li

作者机构：School of Mechanics and Civil EngineeringChina University of Mining and TechnologyBeijing100083China State Key Laboratory of Coal Resources and Safe MiningChina University of Mining and TechnologyBeijing100083China Department of Mechanical EngineeringUniversity of MassachusettsDartmouth02747USA 

出 版 物：《Journal of Rock Mechanics and Geotechnical Engineering》 (岩石力学与岩土工程学报（英文版）)

年 卷 期：2020年第12卷第2期

页      面：297-309页

核心收录：

学科分类：0820[工学-石油与天然气工程] 08[工学] 0818[工学-地质资源与地质工程] 0815[工学-水利工程] 0813[工学-建筑学] 0814[工学-土木工程] 082002[工学-油气田开发工程] 

基　　金：financially supported by National Natural Science Foundation of China(grant No.41877257) Beijing OutstandingYoung Scientist Program(Grant No.BJJWZYJH01201911413037) Shaanxi Coal Group Key Project(Grant No.2018SMHKJA-J-03) Yueqi outstanding scholar Award Program by China University of Mining and Technology(Beijing),China 

主　　题：Longmaxi shale Three-point bending test Fracture toughness Fracture energy Crack propagation Anisotropic cohesive damage Extended finite element method(XFEM) 

摘      要：The mechanical properties and fracturing mechanism of shale containing beddings are critically important in shale gas exploitation and wellbore *** investigate the effects of shale bedding on crack behavior and fracturing mechanism,scanning electron microscope(SEM)with a loading system was employed to carry out three-point bending tests on Longmaxi outcrop *** crack initiation and propagation of Longmaxi shale were observed and recorded by taking photos during *** cracking paths were extracted to calculate the crack length through a MATLAB *** peak load,fracture toughness and fracture energy all increase with the bedding angle from 0°to 90°.The crack length and energy were also found to increase with the bedding angle in the range of 0°-600 and then drop *** fracturing mechanism of shale includes the main crack affected by the bedding angle and disturbed by randomly distributed *** main cracking path was accompanied by several microcrack branches which could form an interconnected crack *** the main crack encounters larger sedimentary particles,it will deflect around the particles and then restore to the initial direction.A numerical technique using extended finite element method(XFEM)coupled with anisotropic cohesive damage criteria was developed,which is able to capture the dependence of crack propagations on bedding angle and sedimentary *** study sheds light on understanding and predicting mesoscale fracture behavior of shale with different bedding angles.