The Applied Research Of Comprehensive Geological Prediction Technology In CenShui Expressway Tunnel Construction

In order to ensure the safety during the tunnel construction, the <Highway TunnelDesign Guideline> regulates that the Geology Forecast should be included during theconstruction as for the tunnel, which is over one thousand meters. But, all the common usedforecast methods have their advantages and disadvantages inevitably, and it’s hard to satisfythe accuracy requirements only with one single method. This paper research severalcommon used forecast methods and their synthetic application based on the Censhuiexpressway highway tunnel, Guangxi Zhuang Autonomous region to improve the forecastaccuracy and decrease the blindness during the tunnel excavation.It makes spot test respectively for three kind of common used physics detect methods,and makes a contrast between the test and realistic excavation result, so as to analyze theapplication requirement for each method. The contrast result shows that the electromagneticwave reflection method has high detect accuracy within30meters, and can detect theexistence of the water, but unable to certify the water quantity and the distribution of therock layer. This method is prone to be affected by the test environment and lead to thewrong explanation. The available detect range of the seismic wave reflection method canreach to100to200meters, and this method can not be used in the shallow and the orificesection, also, the detect effect of the water is bad, and the resolution ration for the littlegeology target is insufficient, but the detect effect for the big geology target is good.Moreover, the related parameters can be back calculated according to the transportationtheory, so as to offer the base for the rank of the surrounding rock. The TEM method hasgood detect effect for high water quantity bad geology target within30to100meters, but itis bad for the high resistance body, and this method is also prone to be affected by theconstruction environment.It introduces the “synthetic forecast technology”, as use three kinds of these physicsdetect technology based on the geology analysis according to the thought that “combinesmany kinds of means, long combined with short”, and introduces the detect criterion for thecritical bad geology body. This kind of forecast method offers reference to the related work.