千米深井厚硬顶板直覆沿空留巷围岩结构优化

Structural optimization of overlying strata for gob-side entry retaining in 1000m deep mine with direct thick and hard roof

针对深部沿空留巷厚硬顶板大面积悬露及采空侧顶板长悬臂劣化围岩应力环境难题,分析了千米深井厚硬顶板直覆沿空留巷矿压显现特征,提出了该条件下沿空留巷超前工作面采场顶板深孔预裂爆破放顶优化与采空侧顶板结构破断卸压相结合的围岩结构优化控制技术;同时基于理论模型与树脂模型结果,分析了厚硬顶板条件留巷充填墙体上方载荷与采空侧顶板悬臂长度的相互关系,指出利于留巷围岩长期稳定的采空侧顶板悬臂长度不大于12 m。相关研究成果成功应用于平煤集团12矿己14-31010工作面沿空留巷,为同等条件下的实施沿空留巷提供了借鉴。

The stress environment of surrounding rock in gob-side entry retaining has been deteriorated by mining field large area hanging, longer roof hanging along gob-side under direct thick and hard roof condition. In order to solve the problem, the characteristics of strata behaviour of gob-side entry retaining with direct thick and hard roof in over 1 000 m deep coal mine have been analyzed in this paper. The structural optimization technology of overlying strata for gob-side entry retaining with hard roof condition has been proposed, which is compounded by roof caving optimization advanced the working face and pressure relief for hanging roof structure cutting along gob-side using the deep hole presplitting blasting. Simultaneously, the relationship between the length of roof hanging along gob-side and the strength acted on filling wall has been obtained, and the paper has pointed out the reasonable length of roof hanging along gob-side for long-term stability of the surrounding rock in gob-side entry retaining is under the condition of no more than 12 m. The related research results have been successfully applied in gob-side entry retaining of 14-31010 working face in Pingdingshan Twelve coal mine, and have provided reference to the implementation of gob-side entry under the same conditions.