近水平层状岩体的松动区分布范围探讨

Study on distribution area of loosen zone in nearly horizontal rock body

西龙池地下厂房围岩岩体结构的类型以缓倾角层状为主,对于顶拱的开挖十分不利。根据地下厂房近两年的声波监测和多点位移计监测结果,确定了围岩的松动圈范围在0.2～1.2m,顶拱处的松动范围最大。然后,对松动圈分布范围进行了数值模拟和弹塑性解析计算。经过对比,数值模拟、弹塑性解析解和实际监测值的松动圈的整体分布规律是一致的,理论计算值是监测值的2～3倍。将理论计算与实际监测结合起来讨论近水平层状岩体的松动区分布范围是有重要指导意义的。

Rock mass structure of the underground powerhouse of Xilongchi Hydropower Station is mostly low-angle stratified rock which is unfavorable for the excavation of the crown. According to the results from both the acoustic monitoring and the multipoint extensometer monitoring on the powerhouse made during past two years, the loosen zone of the rock is defined as 0. 2 - 1.2 m with the maximum on the crown. Therefore, numerical simulation and elastic-plastic analysis are made on the loosen zone. After comparison, the results from the numerical simulation and elastic-plastic analysis accord with the integral distribution law of the loosen zone determined from the field monitoring result, however, the theoretical calculation value is about 2 - 3 times as much as the monitoring value. Consequently, it is significant to study the loosen zone in the nearly horizontal rock body by means of combination of both the theoretical calculation with the field monitoring concerned.