地面L型定向分支孔注浆加固煤层顶板厚风氧化带技术研究

Pre-Grouting Reinfocement Technology with Ground Directional L-shaped Feather Branch Hole for Thick Weathered and Oxidized Zone in Coal Seam Roof

针对薄基岩、厚风氧化带下综采工作面顶板压力大,易形成出水、压架事故的工程问题,采用一种新型L型定向分支孔结构对顶板厚风氧化带进行了地面预注浆,设计了合理的注浆参数和施工技术措施。工程实践结果表明:采用地面多渗透源的注浆方式加固顶板风氧化带,注浆压力大,改善了上覆围岩结构的力学行为,封堵了砂岩裂隙水和上部含水层的导水通道,配套高强液压支架,实现了安全回采,为同类地质条件下工作面开采提供了一种新的技术途径。

It is known that the phenomenon of high pressure,water leakage,fully mechanized supports crushing frequently occurs in the roof of working face with large mining height under thin bedrock and thick weathered or oxidation zone.In this study,a new type of L-shaped directional branch hole structure is adopted to pre-grout the thick weathered and oxidation zone,so that some reasonable grouting parameters and grouting technical measures are designed to prevent the supports crushing accident during coal mining.Engineering practice show that,ground pregrouting with multi-permeability source to reinforce the seam in weathered and oxidized zone,can bear high grouting pressure,improve the mechanical behavior of overlying surrounding rock structure,fill the water channel of upper aquifer and block the cranny water of coal seam roof.With proper use of high-strength hydraulic support,the safe mining is accomplished.The research can provide a new technical approach for mining under thin bedrock coal seam of the similar geological conditions.