A physical model study of surrounding rock failure near a fault under the influence of footwall coal mining
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A physical model study of surrounding rock failure near a fault under the influence of footwall coal mining Shukun Zhang1,2
•
Lu Lu1 • Ziming Wang2 • Shuda Wang2
Received: 4 March 2020 / Revised: 6 June 2020 / Accepted: 27 October 2020 Ó The Author(s) 2020
Abstract A study of the deformation of the surrounding rock and coal pillars near a fault under the influence of mining is conducted on a physical model for the design of coal pillars to support and maintain the roofs of adjacent fault roadways. This research is based on the 15101 mining face in the Baiyangling Coal Mine, Shanxi, China, and uses simulation tests similar to digital speckle test technology to analyse the displacement, strain and vertical stress fields of surrounding rocks near faults to determine the influence of the coal pillar width. The results are as follows. The surrounding rock of the roadway roof fails to form a balance hinge for the massive rock mass. The vertical displacement, vertical strain and other deformation of the surrounding rock near the fault increase steeply as the coal pillar width decreases. The steep increase in deformation corresponds to a coal pillar width of 10 m. When the coal pillar width is 7.5 m, the pressure on the surrounding rock near the footwall of the fault suddenly increases, while the pressure on the hanging wall near the fault increases by only 0.35 MPa. The stress of the rock mass of the hanging wall is not completely shielded by the fault, and part of the load disturbance is still transmitted to the hanging wall via friction. The width of the fault coal pillars at the 15101 working face is determined to be 7.5 m, and the monitoring data verify the rationality of the fault coal pillars. Keywords Fault Mining roadway Surrounding rock Coal pillar Physical model
1 Introduction Coal mining often encounters geological environments with complex structures and faults. When the working face boundary is a fault, to greatly improve the mining production, the coal pillars left between the mining roadways and the faults are often small, and sometimes, no coal pillars are left. Fault cutting disrupts the integrity of the rock strata and has a significant impact on the distribution of mining-induced pressure. The influence of disturbance stress is likely to cause fault activation, coal pillar or & Shukun Zhang [email protected] 1
School of City and Architecture Engineering, Zaozhuang University, Zaozhuang 277160, Shandong, China
2
School of Civil Engineering, Liaoning Technical University, Fuxin 123000, Liaoning, China
roadway failure near the fault, surrounding rock deformation, and roof falls, and it can even impact rock burst accidents. The study of the deformation characteristics of faults and coal pillars during the mining process has important value for maintaining and control of the roof and the design of coal pillars (Jiang et al. 2014). At present, scholars have performed fruitful research on mining-induced pressure in surrounding rocks near faults and the deformation and failure of fault roadways.
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