Mechanism by Which Backfill Body Reduces Amount of Energy Released in Deep Coal Mining

Abstract

Deep coal mining is unavoidable, and the complex mining environments and the increasing dangers associated with ultrahigh energy accumulation and release from mining disturbances renders it extremely difficult to maintain a safe and stable stope. Solid backfilling technology directly uses coal gangue and other solid wastes in the mining area to fill the gob after mining. Support from the backfill body can inhibit the movement of overlying rock strata and significantly alleviate the influence of mining. In this study, the correlations between the deformation of gangue filling material and the characteristics of energy dissipation were examined under lateral uniaxial compression. The strain energy density distributions of backfilling and caving mining methods were simulated using numerical modeling. The results showed that the strain energy density distribution of backfilling mining was less concentrated, and its peak value was lower than that of caving mining by 51.0%, indicating that backfilling could effectively reduce the amount of energy released from mining rocks. The dense backfill mining area of the No. 9301 face in Tangkou Coal Mine was used as a case study. Measures for controlling the backfill body compaction for reducing the amount of energy released from mining rocks were proposed. These measures include optimizing the support structure and filling material formula, controlling the preroof subsidence, and ensuring an appropriate number of tamping strokes. The monitoring results of the backfilling quality, surface subsidence, and microseismic energy of No. 9301 working face in Tangkou Coal Mine showed that when the backfill body filling ratio control value was 82.28%, the total number of microseisms and the amount of energy released from the mining working face were significantly lower compared to those of the caving method. This study demonstrated that the backfill body could effectively reduce the amount of energy released from mining rocks, thereby realizing management of mine earthquake and sustainable deep coal mining.

Surface Subsidence Control during Deep Backfill Coal Mining: A Case Study

“…In this paper, the filling rate was guaranteed by controlling the gradation of filling materials, optimizing the tamping angle and times of the tamping institution, and improving the filling process [16,26]. e specific implementation methods are as follows.…”

“…Finally, along the south-north roads located on the east side of the Sunjia village and Wujia village, 35 measuring points were installed facing measuring lines T1-T35. Total station lead measurement was taken as the standard mode [26]. e measurement results are shown in Figure 12.…”

Mechanical Properties and Deterioration Instability of Filling Body with Gangue-Cement Material Based on AE Experiment

“…In addition, it is also found from the failure trace of the test block that the distribution of failure fractures depends on the location of the uneven weak points of the test block. erefore, the fractures show a very irregular state [29]. Li et al used PFC3D software to simulate the compression deformation of four different particle size grades of coal gangue filling materials [30].…”

Study on the Bearing Characteristics and Application of the Filling Body in Original Roadway Filling and Nonpillar Driving

“…According to the strength characteristics and compaction characteristics of different filling materials, Ning et al [12] pointed out that the compactness and filling rate of filling materials were the key factors affecting the subsidence of overlying strata. Based on the deformation characteristics of roadway surrounding rock and the mechanism of roadway-side support, Qi et al [13] deduced a calculation formula for the width of the road-side support. Huang et al [14] studied the bearing characteristics of underground filling body and the support strength of the working face.…”