Abstract
Affected by the mining activities of the working face, the surrounding rock of the roadway is easily deformed and destroyed. For deep buried roadways, the deformation and destruction of the surrounding rock is particularly prominent. Under the influence of in situ stress fluctuation, 3−1103 tailgate of the Hongqinghe coal mine was in a complex stress environment with a maximum stress exceeding 20 MPa. Affected by mining stress, the roadway behind the working face was seriously deformed. In order to alleviate the deformation of the roadway, directional blasting and cutting measures for the 3−1103 tailgate were adopted in this paper. The mechanism of crack propagation in single-row to three-hole directional blasting was revealed by numerical simulation. The blasted rock was divided into three regions according to the crack condition. The numerical analysis of the cutting heights of 0 m, 10 m, 12 m, and 14 m, respectively, showed the stress peaks of different cutting heights and the deformation law of the surrounding rock. The pressure relief effect was the best at 14 m cutting height. At this time, the peak stress was 39 MPa with the smallest roadway deformation. Based on numerical simulation and theoretical analysis results, engineering tests were carried out. Field monitoring showed that the deformation of the roadway was inversely proportional to the roof cutting height. The higher the cutting height is, the more preferential the roadway is to reach the stable state. It can be concluded that directional blasting can change the surrounding rock structure, control the deformation of the roadway, and play a role in pressure relief. It provides a new measure to control roadway deformation.
Highlights
As the key channel of the coal mine production system, roadway stability is one of the key factors to achieve high production and efficiency
Experts and scholars have carried out relevant research on the deformation mechanism and control measures of the surrounding rock of a deep roadway
Yuan et al [9] established the mechanical model of a circular roadway under a deep dynamic pressure environment and analyzed
Summary
As the key channel of the coal mine production system, roadway stability is one of the key factors to achieve high production and efficiency. Qi [18] put forward the comprehensive pressure relief technology of deep hole presplitting blasting, pressure relief roadway, and coal seam borehole pressure relief, which can improve the stress condition of the roadway surrounding rock and reduce the stress concentration factor Professor He et al proposed the roof cutting and pressure relief gob-side entry and retention technology based on the short arm beam theory in 2008 [19,20,21]. In order to solve the problem of roadway deformation, Yang et al [25] proposed the method of “roof cutting and pressure relief of an adjacent roadway” based on “roof cutting short wall beam” and obtained the optimal blasting roof cutting scheme through the theoretical analysis and field test. A field case study in the Hongqinghe coal mine was presented to validate the numerical results
Sign-in/Register to view highlights & summary 
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call