Study on the Stage Failure Mechanism and Stability Control of Surrounding Rock of Repeated Mining Roadway

Abstract

China is one of the leading countries in the mining and utilization of coal resources, and the problems of coal-mining technology and safety have been concerned by the world, while the serious deformation and destruction of surrounding rock and the difficulty of support have brought inconvenience to the mining of coal resources due to repeated mining. This paper takes the actual engineering 22205 mining roadway in Buertai mine as the research background, through the combination of numerical simulation and field measurement. In this paper, the stress environment, plastic zone, and surrounding rock deformation in the advancing process of coal-mining face are studied, and the stress evolution law of surrounding rock in repeated mining roadway is obtained. It is clarified that the surrounding rock deformation is the failure mechanism under the combined action of principal stress difference and stress direction deflection. As a result, the surrounding rock of the roadway is asymmetrically deformed and destroyed, and the corresponding surrounding rock control scheme is put forward. The results show that the influence of repeated mining on roadway stress environment can be divided into four stages with the mining process: the stability stage of mining influence, the expansion stage of primary mining, the stable stage after primary mining, and the expansion stage of second mining. At the same time, the shape changes of the plastic zone and the displacement monitoring results of the monitoring are analyzed, and the results are obtained; the stage of stress change is suitable, and combined with the failure characteristics of surrounding rock in each stage, it is put forward that reinforcement measures should be taken in the stable stage after mining; the specific reinforcement scheme is determined according to the expansion form of plastic zone and field measurement. The on-site monitoring shows that there is no roof fall accident during the use of the roadway, which ensures the safety in production.

Research of roadway deformation induced by mining disturbances and the use of subsection control technology

“…Yuan and Zhu used a numerical simulation method to study the evolution of the surrounding rock stress under the condition of overlapping coal pillar and mining action. Through the simulation results of the back mining process, it was verified that the deformation and failure of the surrounding rock is the result of the combined action of lateral bearing pressure of the adjacent working face, leading bearing pressure, and stress transfer from the overlapping coal pillar 3‐6 . Yu analyzed the action mechanism of strong mine pressure in a working face in the conditions of multi‐seam mining disturbance and coal pillar influence, and through theoretical analysis and field measurements calculated the depth and range of the stress concentration area 7‐9 .…”

“…Through the simulation results of the back mining process, it was verified that the deformation and failure of the surrounding rock is the result of the combined action of lateral bearing pressure of the adjacent working face, leading bearing pressure, and stress transfer from the overlapping coal pillar. [3][4][5][6] Yu analyzed the action mechanism of strong mine pressure in a working face in the conditions of multi-seam mining disturbance and coal pillar influence, and through theoretical analysis and field measurements calculated the depth and range of the stress concentration area. [7][8][9] Zhang and He et al analyzed the influence of different coal pillars on the stress superposition of the lower coal roadway and showed that the mining disturbance-induced stress superposition of the adjacent coal seams had a strong impact on roadway stability.…”

Analysis of the Failure Characteristics and Main Controlling Factors of Surrounding Rocks Using the Standard Specimen with a Pre-Existing Hole

“…For a long time, academics have always believed that the shape of the plastic zone around a circular hole is circular or elliptical [11], which is suitable for tunnel engineering excavated under isobaric or low-pressure stress conditions but has been proven to be unsuitable in tunneling projects disturbed by high bias stresses [12,13]. Ma Nianjie [14] et al proposed the "*" distribution of the surrounding rock plastic zone for the mining roadway.…”

“…Ma Nianjie [14] et al proposed the "*" distribution of the surrounding rock plastic zone for the mining roadway. After that, the team obtained the implicit equation of the surrounding rock plastic excavated under isobaric or low-pressure stress conditions but has been proven to be unsuitable in tunneling projects disturbed by high bias stresses [12,13]. Ma Nianjie [14] et al proposed the " * " distribution of the surrounding rock plastic zone for the mining roadway.…”

Stability of a Roadway below a Coal Seam under Dynamic Pressure: A Case Study of the 11123 Floor Gas Drainage Roadway of a Mine in Huainan, China

“…ere are also abundant research results relating to the deformation and failure characteristics of rock structures surrounding roadways [17][18][19][20][21][22][23][24]. Li et al [25] used a numerical simulation method to study the mechanism of roadway failure caused by repeated caving in the Huaibei mining area and proposed a new supporting scheme.…”