Asymmetric support technology for gob side entry retaining with high water material

Abstract

The gob side entry retaining with high water material is often used in coal mines. To study the stress evolution characteristics of surrounding rock and asymmetric support control technology of gob side entry retaining with high water material, the evolution law of stress and deformation of surrounding rock in gob side entry retaining during working face mining is studied by theoretical analysis, numerical simulation and field measurement. According to the stress variation of overlying strata during the mining process of the working face, the mechanical models before and after the basic roof fracture were established respectively. The stress and deformation of the filling body and the roof on the side of the filling body are larger, and the stress and deformation of the solid coal and the roof on the side of solid coal are smaller. The maximum stress is at 3 m away from the roadway. The first weighting step distance is 40 m and the periodic weighting step distance is 30 m. Based on the stress and deformation characteristics of the roadway surrounding, the roadway surrounding support is divided into filling bodyside, solid coal side, and middle part of roadway roof. The asymmetric support technology of "filling body+ double row hydraulic prop+ I-beam+ high-strength pretension anchor cable+ high-strength bolt" is proposed. The field engineering practice shows that the surrounding rock control effect of asymmetric support technology with high water material is good.

Method for Determining Spontaneous Combustion Risk in Roof Cutting Gob-Side Entry Retaining U + L Ventilation Goaf for Mining Safety

“…The setting of model porosity in fluid simulation is crucial to achieving accurate simulation results in a goaf, and this setting mainly depends on the correct description of the rock fragmentation coefficient. Generally, the compaction distribution of the RCGSER goaf still follows the "O" circle rule [32]; however, the rock fragmentation coefficient differs considerably near the entranceway [33,34].…”

Solid waste filling and roadway retaining for longwall mining by numerical investigation

“…Some scholars have analysed the technical difficulties and construction keys of the roadway retaining and solid waste filling [ [16] , [17] , [18] , [19] ]. Some scholars have analysed the deficiencies of the roadway retaining and solid waste filling technology, and put forward the formation of roadside support by filling gangue belt and grouting reinforcement of filling body [ 18 , [20] , [21] , [22] ]. Therefore, it further improves the deficiency of this technology in deep filling mining conditions [ [23] , [24] , [25] , [26] ].…”