Study on Presplitting Blasting the Roof Strata of Adjacent Roadway to Control Roadway Deformation

Abstract

In order to solve the problem of roadway deformation based on the theory of “short cantilever beam by roof cutting,” the method of “pressure relief by roof cutting in the adjacent roadway” is proposed. Through presplitting blasting the roadway hard rock layer, the stress propagation path is cut off, and the surrounding rock stress environment of the roadway is improved, to achieve the purpose of controlling the deformation of the roadway caused by stress. Through theoretical analysis, it is determined that the depth of the presplitting blasthole is 17 m, and the angle with the vertical direction is 10°. Based on in situ measurements and tests, by presplitting blasting the roof strata of the adjacent roadway, the maximal value of the working resistance of the hydraulic support in the presplitting blasting side of the working face decreased by 24.9%, and the average volumes of the maximum floor heave, the maximum roof subsidence, and the maximum ribs displacement were reduced by 50.1%, 34.9%, and 41.7%, respectively. This method completely changes the traditional thought patterns of “reinforcing support” to control roadway deformation from “strong support” to “pressure relief.” It provides a new idea for controlling the roadway deformation.

Research on the Deformation Characteristics and Support Technology of a Bottom Gas Extraction Roadway under Repeated Interference

“…When the stress in the surrounding rock is less than the value of concentrated stress, the rock will be destroyed and the stress will transfer to the deeper rock. e concentrated stress will reach equilibrium at a certain location, and the roadway will tend to stabilize [19]. (2) Disturbance stage of coal seam mining: during upper coal seam mining, the bottom gas extraction roadway is disturbed again, mainly due to three disturbances, namely, excavation on the coal roadway, mining of the upper coal face, and mining of the lower coal face.…”

“…A bottom gas extraction roadway is affected by not only the disturbance of its own excavation but also the disturbance of overlying coal seam mining. e deformation characteristics of a roadway are complex [19]. erefore, it is not feasible to explain these phenomena with traditional theoretical approaches under the influence of static pressure.…”

Evolution and application of airflow permeability characteristics of gob in roof cutting and pressure releasing mining method

“…With this method, only one roadway needs to be excavated in a mining face, and there is no coal pillar left between the working faces. Additionally, it has many advantages such as optimizing the stress of surrounding rock, eliminating the need for coal pillars, and reducing the extent of roadway excavation …”

Numerical Simulation Analysis of NPR Anchorage Monitoring of Bedding Rock Landslide in Open‐Pit Mine

“…Under the blasting, rainfall, and human activity, the rock mass of slope weakens, causing a large number of engineering disasters [1][2][3][4][5][6]. e disaster because of large deformation during a landslide in an open-pit mine not only causes huge economic losses but also seriously threatens the safety of life and property of the staff in the mine.…”