Roadway backfill method to prevent geohazards induced by room and pillar mining: a case study in Changxing coal mine, China

Abstract

Abstract. Coal mines in the western areas of China experience low mining rates and induce many geohazards when using the room and pillar mining method. In this research, we proposed a roadway backfill method during longwall mining to target these problems. We tested the mechanical properties of the backfill materials to determine a reasonable ratio of backfill materials for the driving roadway during longwall mining. We also introduced the roadway layout and the backfill mining technique required for this method. Based on the effects of the abutment stress from a single roadway driving task, we designed the distance between roadways and a driving and filling sequence for multiple-roadway driving. By doing so, we found the movement characteristics of the strata with quadratic stabilization for backfill mining during roadway driving. Based on this research, the driving and filling sequence of the 3101 working face in Changxing coal mine was optimized to avoid the superimposed influence of mining-induced stress. According to the analysis of the surface monitoring data, the accumulated maximum subsidence is 15 mm and the maximum horizontal deformation is 0.8 mm m −1 , which indicated that the ground basically had no obvious deformation after the implementation of the roadway backfill method at 3101 working face.

Influential Factors in Transportation and Mechanical Properties of Aeolian Sand-Based Cemented Filling Material

“…A considerable amount of research has recently been conducted on filling materials (coal gangue, fly ash, and construction waste) and microstructural characteristics for coal mines [6][7][8]. Feng et al [9] studied the mechanical properties of cemented filling materials in which gangue was partially replaced by waste concrete.…”

Mining‐induced failure characteristics and surrounding rock control of gob‐side entry driving adjacent to filling working face in the deep coal mine

“…In recent years, with its unique advantages, a variety of backfill mining technologies has gradually been developed for backfill mining, including solids, pastes, and high‐water materials 18 . Zhou et al 19 tested the mechanical properties of backfill materials to determine a reasonable backfill material ratio for the driving roadway during longwall mining. Jiang et al 20 presented an approach for evaluating, designing, and optimizing the gob‐side entry driving and yield pillars by considering the results of numerical simulations and field practice.…”

Mechanical Properties and Failure Behavior of Mortar-Encased Coal Bodies under Impact Loads: Insights from Experimental Investigation

“…The most common reinforcement methods are shotcreting or infilling with solid materials in addition to coal pillars [16,17]. After the coal pillar is wrapped with mortar, a composite bearing structure is formed to jointly bear the overburden load and resist the external disturbance load [18]. Therefore, an accurate assessment of the mechanical properties and failure mechanism of a composite bearing structure is critical for maintaining the stability of the overlying strata.…”