Integrated Geophysics Method Application In ShiBalipu Tunnel Geological Forecast

The terrain of our country is complex and diverse,and the engineering geological conditions of rock masses are complex.The scale and difficulty of tunnel construction are also increasing year by year.Due to the complex surrounding rock structure of the tunnel,geological disasters are prone to occur under unpredictable circumstances,which not only affects the construction progress,but also poses a serious threat to the safety of construction personnel.Therefore,the current advanced geological forecast has been listed as the first problem to be solved before the tunnel construction.The geophysical methods used in geological forecasting mainly include TSP detection technology,Ground Penetrating Radar method,and Transient Electromagnetic method.However,the single geophysical method has weak anti-interference ability,and is easily disturbed by the construction environment,causing misjudgment of forecast results.In order to ensure the safe and effective progress of tunnel construction,it is necessary to study complementary geophysical forecasting methods,perfect interpretation index system and data joint interpretation method,to improve the accuracy of forecasting geological disasters.The choice of these three combined geophysical prospecting methods can restrict each other's prediction results of different geological hazards and improve the fault tolerance rate of a single method.Based on the Shibalipu tunnel project example,this paper compares the difference between the technical theory research,the numerical simulation of disaster types and the sketch of the tunnel face,analyzes the error between the forecast results and the actual excavation,and finds the tunnels suitable for the advanced geological forecast of the tunnels under different disaster types.Useful ways.It has played a certain role in improving the accuracy of forecasting by geophysical methods.The thesis mainly studies the following four aspects:(1)Analyze common tunnel advanced forecasting methods and their advantages and disadvantages,summarize various tunnel geological disasters,and find targeted forecasting methods for different disasters.Theoretical analysis of the application range,applicable conditions,advantages and disadvantages of the three methods,theoretically study the feasibility of the combined forecasting method.(2)A detailed discussion on the basic principles,detection methods,data acquisition and processing and interpretation of the three methods will provide a theoretical basis for forward numerical simulation.(3)Perform forward simulation of disaster imaging of TSP detection technology,transient electromagnetic method,and ground penetrating radar method,and explore the disaster characteristics under typical models.The simulation features are used to verify whether the interpretation of tunnel disasters in practical applications is reasonable,and to analyze the shortcomings of the exploration capabilities of the three methods and the complementarity and constraints between the methods.(4)Interpret the forecast results of the three methods in combination with the Shibalipu tunnel project example,verify whether the interpretation of the potential geological disaster data of the tunnel in the engineering application is correct according to the characteristics of the forward simulation,and combine the engineering geological survey data and the master The results of other forecasting methods such as surface sketches verify the feasibility of the comprehensive geophysical forecasting method.The three methods of the same section are jointly inverted to find common interpretation features and analyze the sources of errors.