高应力超大断面硐室围岩控制对策研究

Surrounding rock control measures of high stress super-large section chamber

针对深部高应力超大断面硐室围岩易失稳的问题,以红庆河煤矿设备换装硐室为工程背景,采用FLAC^3D数值模拟软件分析了在低扰动掘进条件下超大断面硐室的围岩应力分布特征及变形规律,结果表明:高应力条件下,超大断面硐室塑性区范围明显变大,硐室帮部及底板相对于顶板更容易发生失稳,并提出强力一次全断面支护对策,底板锚索采用水泥灌浆实现全长预应力锚固。现场实践表明,硐室围岩稳定,变形量控制在30mm以内。

Based on the problem that the surrounding rock of deep high stress and super large section chamber is unstable,taking the equipment replacement chamber of Hongqinghe Coal Mine as the engineering background,with the numerical simulation method,the stress distribution characteristics and deformation law of the surrounding rock of the super-large crosssection chamber under low-disturbance driving conditions is analyzed.Under high stress conditions,the plastic zone of the super-large cross-section chamber becomes significantly larger;the wall and floor of the chamber are more prone to instability.Based on this,high pre-tensioned stress and intensive bolting system is proposed to control the surrounding rock of the highstress ultra-large section chamber.The floor anchor cable is cement grouted to achieve full-length pre-stressed anchoring.Field practice showed that the chamber was very stable and the deformation was controlled within 30 mm.