Tunnel Typical Geological Disaster Forecast And Warning Research

During the tunnel construction process, the water inflow, burst mud,collapse and other geological disasters are the most important factor that affect the safety and cost of the tunnel construction. It will greatly reduce the construction risk and cost,if we can accurately predicate the location and the scale of the harmful geologic body in front of the tunnel face,and take corresponding treatments. "Prediction and early warning of tunnel geological disasters " as a comprehensive concept,is put forward in recent years,and its research is just at its starting point. The significance and classification of the early warning, and the early warning methods are still in explored. Prediction and early warning of tunnel geological disasters is divided into two parts generally, the first part is the prediction of the unfavorable geological body before the face of tunnel, the second part is the prediction of stability of surrounding rock during the excavation.We must predicted the location, scale and occurrence of fracture zone, Karst caves, Water Strata accuratly before the tunnel excavation.Currently the comprehensive geological prediction method for unfavorable geological body is the combination of geophysical and geological analysis.However,comprehensive prediction involves too many technical method, and their principle, working mode, interpretation parameters are also different. In this paper, the fuzzy comprehensive evaluation method is applied to comprehensive geological prediction work, through giving different weight to different methods,that the conflicting of the different methods are solved,which improve the accuracy of the forecasting results. The core of this method is to determine the weight of each method, we can get a more reasonable weight by collecting and utilizing opinions from many experts.The major geological disaster during the excavation is the large displacement of surrounding rock and support measures,which can cause large deformation or collapse. Therefore, during the excavation process, we must monitoring the stability of surrounding rock.In this paper,we use gray model to predicte the stability of tunnel displacement,and use Gray GM (1,1) to optimize the metabolic model to get a three days short-term forecast. We can predicate the stability of the tunnel according to forecast results and the actual displacement. Through the regression analysis of surveying data to predict the final stable value of rock displacement and stability time.This paper establishs the index for early warning of the Water Strata, fracture zones, Karst caves, faults, large deformation (collapse) based on the previous studies. And dividing the early warning into three grades according to the scale and possibility of occurrence.At the last part, establishs a prediction and early warning system for the disasters using Matlab software, realize the rapid and automation of data process and analysis.