Stability Control of Deep Coal Roadway under the Pressure Relief Effect of Adjacent Roadway with Large Deformation: A Case Study

Abstract

High-efficiency maintenance and control of the deep coal roadway surrounding rock stability is a reliable guarantee for sustainable development of a coal mine. However, it is difficult to control the stability of a roadway that locates near a roadway with large deformation. With return air roadway 21201 (RAR 21201) in Hulusu coal mine as the research background, in situ investigation, theoretical analysis, numerical simulation, and engineering practice were carried out to study pressure relief effect on the surrounding rock after the severe deformation of the roadway. Besides, the feasibility of excavating a new roadway near this damaged one by means of pressure relief effect is also discussed. Results showed that after the strong mining roadway suffered huge loose deformation, the space inside shrank so violently that surrounding rock released high stress to a large extent, which formed certain pressure relief effect on the rock. Through excavating a new roadway near this deformed one, the new roadway could obtain a relative low stress environment with the help of the pressure relief effect, which is beneficial for maintenance and control of itself. Equal row spacing double-bearing ring support technology is proposed and carried out. Engineering practice indicates that the new excavated roadway escaped from possible separation fracture in the roof anchoring range, and the surrounding rock deformation of the new roadway is well controlled, which verifies the pressure relief effect mentioned. This paper provides a reference for scientific mining under the condition of deep buried and high stress mining in western China.

Zoning Control Technology of Gob-Side Roadway Driving with Small Coal Pillar Facing Mining in a Special Isolated Island Working Face: A Case Study

“…Especially for the roadway roof, the ability of single anchor layer to resist stress disturbance low. Therefore, on the basis of constructing the bearing ring of shallow rock foundation, a reinforced bearing ring of deep rock mass was formed by arranging the roof anchor cable in equal rows with the anchor bolt [21,22], which anchored the bearing ring of shallow foundation with the deeper stable rock mass to form the coordinated bearing support technology of a thick roof anchored with a double circle layer. It not only avoided the concentrated development of separations and fractures on the support interface when the anchor horizon was simplified, but also strengthened the ability of roof rock to resist stress disturbance (Figure 6).…”

The Floor Heave Mechanism and Control Technology of Gob-Side Entry Retaining of Soft Rock Floor

“…[2,3]. High-stress superposition in deep mines results in serious floor heave problems in mining roadways [4][5][6], which affects mine transportation and the efficient advancement of the working face [7][8][9][10]. An urgent need exists to propose a more rational and effective technology scheme for controlling floor heave in order to promote the sustainable development of gob-side entry retaining technology and resource mining in the coal mining industry.…”

Study on Failure Mechanism of Roadway Surrounding Rock and Hierarchical Continuous Support Technology in Unidirectional Fault Area

“…Coal has been the main energy in China for a long time. With the depletion of shallow coal resources, deep mining has become normal in coal resource development in China [1][2][3]. Compared with shallow mining, the rock mass in deep mining is in a mechanical environment featured with "Three Highs and One Disturbance", namely, high stress, high seepage pressure, high temperature, and strong mining disturbance.…”