深埋隧洞围岩分类方法--JPHC分类

现有围岩分类方法只适用于中低地应力、低外水压力条件,在高地应力、高外水压力条件下的适用性差.某深埋隧洞地应力高达20～40 MPa、局部外水压力高达1～10 MPa,具有高地应力、高外水压力的特点.以该深埋隧洞为例,对<水利水电工程地质勘察规范>中的围岩分类方法(HC分类)进行了改进.通过HC分类与Q系统在该隧洞分类结果的相关性、一致性分析,引入地应力修正系数、岩爆烈度、水力劈裂的临界水头压力等,建立了高地应力、高外水压力条件下的围岩分类方法--JPHC分类.该方法在某深埋隧洞围岩分类中适用性好,并可推广使用.

A surrounding rock mass classification method: JPHC method for the deep buried tunnels

The existing surrounding rock mass classification methods are only proper to the conditions of low or middle field stress and low water pressure. By now, these methods are not proper to the conditions of the high field stress and high water pressure. There is a deep buried funnel in China which has 20 to 42 MPa field stress and 1 to 10 MPa water pressure. By analyzing the classification results of different methods in this tunnel, this paper proposes a surrounding rock mass classification method called JPHC method. It can be suited to the conditions of the high field stress and high water pressure. The JPHC method is based on the HC method of the Code For Water Resources And Hydropower Engineering Geological Investigation in China. With the correlation and compatibility between the HC method and the Q system in this tunnel being analyzed, the JPHC method is set up by introducing the field stress update factor, the rock burst intensity and the critical water pressure resulting in hydro splitting. The classification results show that the applicability of JPHC method in this deep buried tunnel is very good. More important, JPHC method can be popularized.