The supporting technology of retaining small coal pillars in a double roadway layout can effectively relieve the tension of mining and excavation replacement and improve the coal recovery rate. The critical difficulty is that the supporting structure on both sides of the small coal pillar has not established an effective mechanical connection, and the improvement of the bearing capacity of the coal pillar is limited, so it is difficult to achieve long-term stability control of the small coal pillar. Taking the 301 and 302 working faces of Gaojiapu Coal Mine as the engineering background, this paper first constructs the overburden structure model of the whole process of mining with small coal pillars in a double roadway layout, obtains the load calculation and strength calculation methods of small coal pillars through the analysis of the mechanism of small coal pillars surrounding rock mechanics, and gives the selection design of support parameters of anchor cables and concrete filled steel tubular piers; Secondly, the influence rules of physical and mechanical parameters such as axial load, elastic modulus and residual strength of anchor solid under different reinforcement methods and the lateral reinforcement coefficient of anchor cable are obtained through experiments. Finally, the support parameters and the coal pillar width are reasonably designed. The field monitoring data show that the reinforcement technology of a small coal pillar with anchor cable as the main body can effectively control the deformation of the small coal pillar, which has specific guiding significance and application value for solving the long-term stability control problem of small coal pillar under the influence of mining.

The interaction of mining and the surface water or aquifer system in varying overburden strata conditions is one of the most critical aspects of sustainable mining practices, that can lead to water loss or water inrush into openings. This paper examined this phenomenon in a complex strata condition via a case study, and proposed a new mining design to minimize the impact of longwall mining on the overlaying aquifer. A range of factors have been identified contributing to the potential disturbance of the aquifer, including the extent of the water-rich area, the characteristics of overburden rock units, and the development height of the water-conducting fracture zone. In this study, the transient electromagnetic method and the high-density three-dimensional electrical method were used to identify two areas prone to water inrush danger in the working face. The vertical range of the water-rich abnormal area 1 is 45–60 m away from the roof, with an area of 3334 m2. The vertical range of the water-rich abnormal area 2 is 30–60 m away from the roof, with an area of approximately 2913 m2. The bedrock drilling method was used to determine that the thinnest part of the bedrock, with a thickness of approximately 60 m, and the thickest part, with a thickness of approximately 180 m. The maximum mining-induced height of the fracture zone was 42.64 m using empirical method, theoretical prediction based on the rock stratum group, field monitoring. In summary, the high risk area was determined, and the analysis shows that the size of the water prevention) pillar was 52.6 m, which was smaller than the safe water prevention pillar actually set in the mining range. The research conclusion provides important safety guidance significance for the mining of similar mines.