Highly efficient maintenance and control of the deep strong mining roadway's stability is a reliable guarantee for the safe production and sustainable development of a coal mine. With return air roadway 4106 in Wenjiapo coal mine as the research background, an in situ investigation, numerical simulation, and engineering practice were carried out to reveal the stress distribution and surrounding rock deformation and failure characteristics of a strong mining roadway. The numerical simulation results show that both first mining and secondary mining are positively correlated with the deformation and failure of roadway surrounding rock. The peak abutment pressure of the coal pillar near the goaf caused by first mining and secondary mining are 28.7 and 35.6 MPa, respectively, with a 24% increase. During the first mining period, the total deformation of the roof and floor of the roadway and the two sides was 1160 and 1436 mm, respectively. During the second mining period, the total deformation of the roof and floor of the roadway in a working face advance gradually increased from 1737 mm 80 m away from the working face to 2281 mm at the working face, and the total deformation of the two sidewalls gradually increased from 2094 mm 80 m away from the working face to 2211 mm at the working face. The damage to the roadway caused by secondary mining was much greater than that caused by the first mining. The collaborative control technology of long anchorage-top-cutting blasting stress relief is proposed to control the stability of the roadway. The engineering practice shows that the deformation of the roadway is effectively controlled under strong mining disturbance, and the maximum deformations of the roof, floor and sidewall are 17, 23, and 11 mm, respectively.

Goaf-side roadway driving with narrow coal pillars could obviously improve coal resource recovery rates compared with traditional large, wide pillars, and this is pivotal to the sustainable development of underground mines. However, it is very difficult to control the stability of goaf-side roadway driving, especially in deep, thick coal seams with large and high working faces. In order to control the stability of goaf-side entry driving in working face 210106 of the deep and thick coal seam in Xinji No. 2 Coal Mine in Anhui Province of China, we carried out field investigations, theoretical calculations, numerical simulations, and an engineering practice to identify the main factors influencing the deformation of the surrounding rock in order to optimize the width of the narrow coal pillar and to propose countermeasures for goaf-side entry driving. Our results show that the main factors influencing deformation of the rock surrounding the roadways at working face 210106 in Xinji No. 2 Coal Mine include high ground stress, large mining height, thick sandstone in the roof, and the residual abutment pressure of the adjacent goaf. The results obtained from theoretical calculations, the numerical simulations, and the engineering practice indicate that a 5 m-wide coal pillar is relatively appropriate and feasible. The countermeasures of pressure relief by blasting roof cutting and bolt grouting reinforcement were carried out to control the stability for goaf-side entry driving. Field measurements indicated that deformations of goaf-side entry driving in deep, thick coal seams could be efficiently controlled. The maximum deformations of sidewall-to-sidewall and roof-to-floor were 100 mm and 350 mm, respectively.

In view of the serious deformation of surrounding rock of deep strong mining roadway, this paper takes 4203 return airway in Jianxin Mine as the engineering background, and uses FLAC3D numerical simulation software to simulate the stress distribution law of roadway and the deformation law of surrounding rock of roadway after three schemes of “short bolt + long anchor cable”, “long bolt + short anchor cable” and “long bolt + short anchor cable + pressure relief” are adopted when the roadway is disturbed by tunneling and secondary mining. The results show that increasing the bolt length can effectively reduce the roof deformation, and pressure relief can effectively improve the stress environment of roadway surrounding rock. The experimental section was set up in 4203 return airway, which proved that the collaborative control of long anchorage and pressure relief had obvious effect on the control of roadway deformation and the improvement of stress environment.

为解决我国西部某矿泥质软岩巷道950运输石门底鼓严重的问题,对巷道底鼓的影响因素进行了分析,发现巷道底鼓主要受埋深大、构造应力、开采扰动、泥岩特性、地下水等因素的影响.研究表明,该巷道底板最小加固深度应达到4.2 m.在原支护的基础上,设计了底板加固和底板未加固2种支护新方案,并采用数值模拟对2种方案进行对比,得出加固底板的方案可有效改善巷道围岩应力条件,降低底鼓量,为相似矿井巷道底鼓治理提供了借鉴.

Rock burst is a typical dynamic disaster in deep underground coal mining. Based on the support problems of the deep roadways in fully mechanized caving face 401111 of Hujiahe Coal Mine suffering from rock burst in Shaanxi Province of China, the failure law and influencing factors of the surrounding rock of the roadway are analyzed. The results show that the deformation of surrounding rock in the roadway shows the characteristics of elastic, plastic transformation, rheology, and expansion. At the same time, it has the typical characteristics of deep roadway, such as the fast deformation speed, long duration, asymmetric deformation, and large loose broken area of surrounding rock. Based on the principle of “strengthening support in shallow zones” and “deep pressure relief in deep zones” in the surrounding rock, the control scheme of surrounding rock in the return roadway of fully mechanized caving working face 401111 is proposed by taking the large diameter pressure relief and deep hole blasting as the main means of pressure relief. The practice shows that the surrounding rock of the return roadway is relatively stable after the implementation of the new scheme, which shows that the design of the new support scheme is reasonable and reliable. It is of great significance for the stability control of surrounding rock of the mining roadway suffering from rock burst.

Goaf-side roadway driving with narrow coal pillars could obviously improve the coal recovery rates compared to traditional wide pillars of 15–40 m. However, it is difficult to control the stability of goaf-side roadway driving, especially in the deep island coal working face. To control the stability using fully mechanized caving, working face 4206 in Jianxin Coal Mine in the Shaanxi Province of China, field investigation, theoretical analysis, and numerical simulation were performed to obtain the main influencing factors of the surrounding rock deformation and reveal the characteristics of stress distribution, plastic zones, and deformations of the surrounding rock of roadways with coal pillars of different widths. Results show that the main influencing factors of surrounding rock deformation of roadways in the island working face 4206 in Jianxin Coal Mine include large, buried depth, thick coal seam, large coal pillars, and island working face with high stress concentration. Moreover, the reasonable coal pillar width is 8 m. The stress concentration and the damage of the 8-m-wide coal pillar are smaller, and the corresponding deformation is lower than that of the other pillars, which is beneficial to the stability of the Goaf-side roadway driving.

The stability of mining roadways is pivotal to safe mining in deep underground coal mines. In order to control the stability of mining roadways in deep mines, this paper studies the cooperative control effect of pressure relief and long bolt support for deep roadway under strong mining disturbance of adjacent working face in Wenjiapo Coal Mine in West China. The numerical calculation software FLAC 3D was used to simulate the distribution law of the displacement, stress and plastic zone around the roadway under the disturbance of excavation and working face mining with three support schemes: “short bolt + long cable”, “long bolt + short cable”, and “long bolt + short cable + drillholes and cutting grooves pressure relief”. The results show that extending the length of bolt can ensure the supporting effect while reducing the consumption of anchor cables in the roof, and can reduce the roadway floor heave by 5.5%. Moreover, the peak lateral pressure of the roadway is reduced by 12.5%, the peak value is shifted to the depth by 6 m, and the floor heave of the roadway is reduced by 36% when the countermeasures of pressure relief in the ribs and floor are adopted. This indicates that the schemes of pressure relief and long bolt support has a significant beneficial effect on decreasing the high stress environment and controlling the deformation of roadway.