Strata behavior and control strategy of backfilling collaborate with caving fully-mechanized mining

Abstract

This article analyzes the technical difficulties in full-section backfill mining and briefly introduces the technical principle and advantages of backfilling combined with caving fully mechanized mining (BCCFM). To reveal the strata behavior law of the BCCFM workface, this work establishes a three-dimensional numerical model and designs a simulation method by dynamically updating the modulus parameter of the filling body. By the analysis of numerical simulation, the following conclusions about strata behavior of the BCCFM workface were drawn. (1) The strata behavior of the BCCFM workface shows significant nonsymmetrical characteristics, and the pressure in the caving section is higher than that in the backfilling section. φ has the greatest influence on the backfilling section and the least influence on the caving section. C has a significant influence on the range of abutment pressure in the backfilling section. (2) There exits the transition area with strong mine pressure of the BCCFM workface. φ and C have significant effect on the degree of pressure concentration but little effect on the influence range of strong mine pressure in the transition area. (3) Under different conditions, the influence range of strong mine pressure is all less than 6 m. This article puts forward a control strategy of mine pressure in the transition area, which is appropriately improving the strength of the transition hydraulic support within the influence range (6 m) in the transition area according to the pressure concentration coefficient. The field measurement value of Ji15-31010 workface was consistent with numerical simulation, which verifies the reliability of control strategy of the BCCFM workface.

Isolated Overburden Grout Injection Technology Mining and Grouting Parameters Discussion and Redesign

“…solid lling [5,7], paste lling [8,9], and slurry lling [10]. Bed-separation lling mining refers to introducing ller material into a cavity, primarily via the Isolated Overburden Grout Injection Technology.…”

“…Implementing advanced mining technology guarantees the comprehensive extraction of coal resources while facilitating the reintegration of gangue trash back into the mining site. The mitigation of ground deformation and the proper disposal of waste material during mining operations can signi cantly decrease environmental pollution and facilitate the implementation of environmentally friendly and sustainable coal mining practices [4,5]. The mining process can be classi ed into two categories based on the location of waste recharges: extraction area lling mining [6] and bed-separation lling mining.…”