Deformation characteristics and reinforcement technology for entry subjected to mining-induced stresses
Open Access
- 1 September 2011
- journal article
- research article
- Published by Elsevier BV in Journal of Rock Mechanics and Geotechnical Engineering
- Vol. 3 (3), 207-219
- https://doi.org/10.3724/sp.j.1235.2011.00207
Abstract
The entry at Zhangcun coal mine in Lu'an coal mining area in Shanxi Province suffered from severe mining-induced stresses with the heading face driven oppositely to an adjacent working face. In this paper, the characteristics of deformation and failure of the entry were investigated in terms of the tempo-spatial relations between heading and working faces through field study and numerical modeling. The three-dimensional (3D) finite difference models were built to investigate stresses, displacements and damages in the surrounding rocks of the entry and the working face. The field study includes selection of reinforcing methods and materials, design parameters, and determination of cable prestress. The monitoring data of entry deformation and stress along the cables during every stage were presented. The state of the reinforced entry was evaluated based on the monitoring data. The results demonstrate that before the heading face of the entry crosses the adjacent working face, the influence of advanced abutment pressure caused by adjacent working face upon the entry is not significant. After they cross each other, however, the lateral abutment pressure will have an evident impact on the entry. The displacement rate of the entry will be greatly increased and reaches a certain value within a certain distance between the heading face and the working face. Then, it will increase again with the presence of secondary mining-induced pressure on the entry when the present working face advances. The fully-grouted cable with short length, high strength and high prestress is an effective way to reinforce the entry suffering from severe mining-induced stresses, which greatly reduces the displacement and failure possibility of the entry. Finally, the principles and recommendations for reinforcing design of entries suffering from severe mining-induced stresses were proposed according to field study, numerical modeling and experiences from other coal mines. Problems encountered in field study and suggestions for reinforcement were also discussed.Keywords
This publication has 8 references indexed in Scilit:
- Development of high pretensioned and intensive supporting system and its application in coal mine roadwaysProcedia Earth and Planetary Science, 2009
- An empirical method for design of grouted bolts in rock tunnels based on the Geological Strength Index (GSI)Engineering Geology, 2009
- A method for the design of longwall gateroad roof supportInternational Journal of Rock Mechanics and Mining Sciences, 2009
- Effect of pre-tensioned rock bolts on stress redistribution around a roadway—insight from numerical modelingJournal of China University of Mining and Technology, 2008
- Quantifying the performance of resin anchored rock bolts in the Australian underground hard rock mining industryInternational Journal of Rock Mechanics and Mining Sciences, 2008
- Rock support design based on the concept of pressure archInternational Journal of Rock Mechanics and Mining Sciences, 2006
- Analytical models for rock boltsInternational Journal of Rock Mechanics and Mining Sciences, 1999
- Roof bolting in underground mining: a state-of-the-art reviewGeotechnical and Geological Engineering, 1984