Research on theory, simulation and measurement of stress behavior under regenerated roof condition

Xuelong Li, Shaojie Chen, Qiming Zhang, Xin Gao and Fan Feng

Abstract

To determine ground stress behavior under the special condition of a regenerated roof, we established a model of elastic rectangular cantilever thin plates. Moreover, the critical conditions for bending and fracturing the regenerated roof during mining were analysed. Meanwhile, by applying continua FLAC-3D numerical simulation, this research simulated changes in the stress and strain on a regenerated roof during mining and proposed prevention and control methods for dynamic disasters. The results show that: (1) the thinner the regenerated roof, the larger the tensile stress on the roof based on analysis using the theoretical model. Furthermore, the longer the advance distance during mining, the greater the tensile stress on the regenerated roof. (2) By analysing simulation results, during the fracturing of the regenerated roof, roof displacement firstly suddenly increases and then gradually decreases to be stable. Floor-heave-induced displacement presents a divergent state, that is, increases outwards in an elliptical manner. (3) For control of the regenerated roof, monitoring on activities of the roof should be strengthened and stress should be relieved timeously. Moreover, effective support methods should be taken to prevent development of hazards on working faces and roadways caused by the widespread behavior of the roof.

Key Words

elastic rectangular cantilever thin plate; ground stress behavior; numerical simulation; regenerated roof; roof control

Address

Xuelong Li: 1.) State Key Laboratory of Mining Disaster Prevention and Control, Shandong University of Science and Technology, Qingdao, 266590, Shandong, China 2.) State Key Laboratory of Coal Resources and Safe Mining, China University of Mining and Technology, Xuzhou, 221116, Jiangsu, China 3.)College of Energy and Mining Engineering, Shandong University of Science and Technology, Qingdao, 266590, Shandong, China 4.)State Key Laboratory of Coal Mine Disaster Dynamics and Control, College of Resource and Safety Engineering, Chongqing University, Chongqing 400030, China Shaojie Chen: 1.)State Key Laboratory of Mining Disaster Prevention and Control, Shandong University of Science and Technology, Qingdao, 266590, Shandong, China 2.) College of Energy and Mining Engineering, Shandong University of Science and Technology, Qingdao, 266590, Shandong, China Qiming Zhang: State Key Laboratory of Coal Resources and Safe Mining, China University of Mining and Technology, Xuzhou, 221116, Jiangsu, China Xin Gao and Fan Feng: State Key Laboratory of Mining Disaster Prevention and Control, Shandong University of Science and Technology, Qingdao, 266590, Shandong, China

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