Formation and evolution of gas flow channels in the abutment pressure area

作     者：Zhang Yong Zhang Xibin Xu Lifeng Zhang Jiangli Zhou Genli 

作者机构：Faculty of Resources and Safety EngineeringChina University of Mining and Technology Huaneng Coal Industry Co.Ltd. 

出 版 物：《International Journal of Mining Science and Technology》 (矿业科学技术学报（英文版）)

年 卷 期：2012年第22卷第6期

页      面：801-807页

核心收录：

学科分类：0819[工学-矿业工程] 081903[工学-安全技术及工程] 08[工学] 

基　　金：supported by a Grant from the State Key Basic Research Program of China(No.2011CB201204) the Central University Basic Scientific Research Business Expenses(No.2011ZY05) 

主　　题：Abutment pressure Gas flow channels Fracture extension mechanism Fracture development characteristics Evolution process 

摘      要：The permeability of coal ahead of the working face obviously changes dues to changes in abutment *** formation and evolution of gas flow channels within the abutment pressure area was studied by analyzing the fracture extension mechanism and fracture development in different zones of the abutment pressure *** and damage mechanics theory is used to understand the *** following two techniques were used to understand the evolution of gas flow channels:field observation of the characteristic fractures at different positions relative to the working face and fluorescence micrographs of prepared coal *** tensile fractures develop along an approximately vertical direction that forms a microscopic network of channels in areas of stress *** abutment pressure affects the local stress and,hence,the local gas *** fractures induced by large deformation and plastic flow form macroscopically networked channels in the reduced stress *** to the working face the gas flow channels evolve from microscopic to macroscopic and from isolated to *** permeability continuously increases during this *** is corroborated by field observations of the displacement of top coal and the gas flow from gas extraction drillings.