Analysis of Surrounding Rock Control Technology and Its Application on a Dynamic Pressure Roadway in a Thick Coal Seam

Abstract

The deformation control of roadways surrounded by rock in the fully mechanized amplification sections of extra-thick coal seams is problematic. To analyze the failure and failure characteristics of a support frame, as well as the deformation and failure processes of the surrounding rock, through theoretical analysis and industrial tests, the deformation and support conditions of a return airway of a fully mechanized caving face in an extra-thick coal seam in the Yangchangwan Coal Mine, in the Ningdong mining, area were examined. Combined with limit equilibrium theory and roadway section size, the width of the coal pillar of the return air roadway at the 130,205 working face was calculated to be 6 m. The layout scheme and implementation parameters of roof blasting pressure relief, coal pillar grouting modification, and bolt (cable) support were designed. Based on the analysis, a “Coal pillar optimization–roof cutting destressing–routing modification–rock bolting” system for surrounding rock control in synergy with the fully enlarged section mining roadway in the extra-thick coal seam was proposed, and the deformation of the surrounding rock was monitored, along with the stress of the support body and the grouting effect on the site. Field experiments show that after the implementation of the surrounding rock control in synergy with the roadway, the maximum subsidence of the top plate was 55 mm, the maximum bottom heave of the bottom plate was 55 mm, the maximum values of the upper and lower side drums were 30 mm and 70 mm, respectively, and the breaking rate of the bolt (cable) and the deformation of the surrounding rock of the roadway was reduced by more than 90% and 70%, respectively. The effective performance of the coal pillar grouting was observed as well. Field practice of the roadway surrounding rock control in the synergy method indicated that rock deformation was effectively controlled, and the successful application of this technology was able to provide reliable technical and theoretical support for the Ningdong mining area and mines with similar conditions.

Stability Control Technology for Surrounding Rocks in Gob-Side Entry Driving with Small Coal Pillars under Dynamic Pressure

“…As a working face advances, its main roof undergoes fracture and subsidence under the effect of its own weight and the overlying strata [25][26][27]. The structural model of the roof above the gob drift, as shown in Figure 1, is established.…”

Research on Collaborative Control Technology of Pressure Relief and Support for Retaining Roadway along Goaf with Hard Roof

“…Hao et al [34] proposed a "Coal pillar optimization-roof cutting destressing-routing modification-rock bolting" system for surrounding rock control in synergy with the fully enlarged section mining roadway in the extra-thick coal seam, and rock deformation was effectively controlled. Tian et al [35] built a mechanical model of a hard roof to analyze the pressure relief roof cutting process for the retention of the gob-side entry and identify the critical stage of control of roadway stability during pressure relief roof cutting.…”

Control Effect Analysis and Engineering Application of Anchor Cable Beam-Truss Structure on Large-Deformation Roadway in Deep Coal Mine

“…To this end, scholars have proposed various types of active, passive, and combined supports through a variety of methods [3][4][5]. Overall, the roadway surrounding-rock control can be divided into fve basic support forms, namely, the basic support within the roadway [6,7] (wood bracket, metal bracket, and stone bracket), strengthening support in roadway [8,9] (permanent strengthening support and temporary strengthening support such as single hydraulic prop), roadway side support [10,11] (wood crib, dense pillar, gangue wall, concrete wall, and flling wall), grouting modifcation [12][13][14] (ordinary portland cement, Marysan, and new polymer organic and inorganic modifed materials), nonsingle support form [15][16][17] (above two and multiple combined support technologies). Te surroundingrock supporting theory of coal mine roadway mainly includes suspension theory, composite beam theory, composite arch theory, maximum horizontal stress theory, and surrounding rock strength strengthening theory [18].…”