工作面过空巷基本顶超前破断机制及控制技术  

Mechanism of advance fracture of main roof and its control technology when workface crossing abandoned roadway

作　　者：刘畅[1,2] 张俊文[1] 杨增强[1] 弓培林[2] 王开[2] 张小强[2] 李玉琳[3] LIU Chang;ZHANG Jun-wen;YANG Zeng-qiang;GONG Pei-lin;WANG Kai;ZHANG Xiao-qiang;LI Yu-lin(College of Resources and Safety Engineering, China University of Mining and Technology （Beijing）, Beijing 100083, China;College of Mining Engineering, Taiyuan University of Technology, Taiyuan, Shanxi 030024, China;Institute of Mining Engineering, HeilonNiang University of Science and Technology, Harbin, Heilongiiang 150022, China)

机构地区：[1]中国矿业大学(北京)资源与安全工程学院,北京100083 [2]太原理工大学矿业工程学院,山西太原030024 [3]黑龙江科技大学矿业工程学院,黑龙江哈尔滨150022

出　　处：《岩土力学》2018年第4期1411-1421,共11页Rock and Soil Mechanics

基　　金：国家重点研发计划专项资助(No.2016YFC0600901);国家十二五科技支撑计划项目(No.2012BAB13B04);国家自然科学基金资助项目(No.51574114;No.51674263);国家重点研发计划(No.2016YFC0801403)~~

摘　　要：以工作面进入平行空巷、回撤通道时顶板超前破断、巷道被掩埋、支架压架的事故为研究对象,通过相似模拟试验对比了工作面过不同宽度空巷、充填与否时围岩破坏特征、应力变化和支架载荷变化,展现了工作面过大断面空巷基本顶超前破断及其灾变演化过程。研究表明:超前破断会导致基本顶一次性破断长度增加、上覆亚关键层同时破断。一旦发生超前破断,现有支护技术很难避免压架,故预防出现超前破断最为重要。鉴于此,运用Winkler地基梁理论对基本顶中弯矩和挠度进行了计算,解释了试验中围岩破断特征、支承应力和支架载荷的变化,给出了基本顶超前破断的机制:煤柱失稳是导致出现超前破断的主要因素,提高煤柱强度有利于预防超前破断。据此提出了局部注浆充填技术使煤柱由单轴压缩变为三轴压缩,提高煤柱支撑能力,并在现场实践中得到了验证。Similar simulation experiments were carried out to study the chock sudden closure incident of hydraulic supports when the workface crossed the abandoned roadway or accessed to the removal roadway. The failure characteristics of surrounding rock, the abutment pressure and the working resistance of supports were investigated through the experiments, respectively. Results indicate that the advance fracture appeares before the incident when the workface crosses a large section roadway. The advance fracture leads to an increase of the block length, comparing to that in a normal periodic weighting. Meanwhile, the inferior key stratum brokes and then slides down to the main roof. Once the advance fracture occurrs, conventional supports are unable to prevent the block sliding, which indicates that an incident takes place. Therefore, the most important thing is to prevent the occurrence of advance fracture. To investigate the main causes for the advance fracture, bending moment and deflection of the main roof are calculated by the Winkler foundation beam theory. The calculated results comprehensively explain the failure characteristics of surrounding rock, the abutment pressure and the working resistance of supports. Finally, it is revealed that the failure of coal pillar is the reason for advance fracture of the main roof. Hence, it is significant to improve the strength of coal pillar. At last, a roadway filling strategy is put forward to make uniaxial compression of coal pillar into triaxial compression by Shenghua coal mine. In-situ tests verifies that the strength of coal pillar is successfully increased.

关 键 词：过空巷 相似模拟 超前破断 煤柱失稳 

分 类 号：TU457[建筑科学—岩土工程]