弱胶结软岩地层相邻大断面巷道合理间距研究

基于相邻巷道开挖扰动和爆破振动对已有巷道影响的理论分析,推导了相邻大断面巷道合理间距的确定公式。以麦垛山马头门硐室与主变电所巷道间距设计为依托,利用数值方法计算变间距多个模型的开挖扰动影响,以确定其巷道间距。研究结果表明,麦垛山马头门硐室与主变电所巷道间距的理论计算值应不低于36.6 m;数值分析发现当巷道间距为40 m时,马头门硐室与主变电所巷道中间围岩的应力场已接近原岩应力,巷道围岩位移场与塑性区基本趋于对称稳定,马头门硐室支护荷载与未受影响前基本一致。利用上述研究成果,综合现场施工状况,最终确定其间距为40 m。工程施工后硐室与巷道稳定,验证了在软岩地层中该巷道间距设计的科学合理性。

Reasonable Spacing for Adjacent Large-section Roadway in Weakly Cemented Soft Rock Strata

A formula for the reasonable spacing of large?section roadway was deduced based on the analysis of impact of the disturbance from the excavation of adjacent roadway and blasting vibration on the existing roadway. With the spacing between Matou chamber and main substation roadway in Maiduo Mountain Coal Mine as an example, the excavation disturbance for several models with different spacing was calculated with numeric method, for deciding the rational roadway spacing in the design. The study shows that the theoretical spacing between Matou chamber and main substation roadway shall be no less than 36. 6 m. It is found that with the roadway spacing at 40 m, the stress field of the surrounding wall between chamber and the main substation roadway is close to the stress of primary rock. The displacement field of roadway surrounding rock is in the symmetry to the plastic zone, and the support load of chamber is basically unchanged. Based on the above results, the on?site working condition was taken into consideration to finally set the spacing at 40 m. Practice showed both the chamber and roadway remained stable after engineering construction, which has proved the spacing design scientifically reasonable.