Application Effect Of Comprehensive Geophysical Prospecting Method In Tunnel Advanced Prediction

Tunnel construction has been the development of traffic and municipal construction in our country is big,in the topographic conditions and complex geological structure area,fault zone,folds and joints structure development,abundant water,poor engineering geological conditions of tunnel surrounding rock tunnel construction,increase the difficulty and risk,the construction problems have more complex,so how to improve the accuracy of complex tunnel prediction has become urgent to solve the problem.In this paper,the theory of numerical simulation and field test,combined with the engineering verification,to study the comprehensive geophysical prediction technology of tunnel in complex geological area,in order to improve the prediction accuracy of the tunnel.The specific research contents and achievements are as follows:(1)combined with the common faults,karst tunnel,coal seam gas geological disaster characteristics and research situation at home and abroad,the various methods of tunnel geological prediction are analyzed,and the feasibility of the advantages of the TSP method and geological radar method as comprehensive prediction method.Based on the analysis of the limitation of the single geophysical prospecting method,the superiority of the integrated geophysical prospecting technique in eliminating the multiple solutions of single method is compared.According to the causes and harm of complicated tunnel geological disasters,through advanced detection existing prediction technology on the comparative study of the tunnel,found that geological radar method and TSP method to confirm each other,play their own characteristics,and improve the technical support and reliable guarantee for tunnel construction.(2)the working principle and the observation system of TSP prediction method,the write code is simulated in the propagation characteristics of seismic wave in the tunnel whole space and response characteristics,and elastic wave characteristics of the faults,common tunnel prediction and hole filling type karst cave and other geological disasters do numerical simulation,which make up the data of CO seismic wave in the tunnel underground space shortcomings,by comparing the measured data,judge the rationality and feasibility.Simulation results were collected with image feature data of typical anomaly area,compared with existing software to explain the basis and method,reference map layer and physical mechanical parameters of two-dimensional results of tunnel TSP reflection typical disaster anomaly area,the results of image interpretation signs listed,summed up the TSP method in tunnel geological forecast.(3)study on the working principle of GPR,observation methods and data interpretation method,using GprMax simulation software,geological radar exploration of tunnel anomaly carries on the numerical simulation,mainly from several karst cavity,water cave,in front of the tunnel face faults of different characteristics,rich in the karst and fault radar Limited data,by comparing the actual image,judge the rationality and feasibility.Collect electromagnetic wave characteristics of forward simulation results of measured geological radar anomaly area,summarize and improve the geological radar method in advanced detection criterion in the tunnel,and help technical personnel to identify the different forms and characteristics of anomaly.(4)through the analysis of geological radar and TSP integrated geophysical technique application in the prediction of advance in the same tunnel karst detection prediction method of the TSP long distance for the weak fault zone and lithologic interface surface structure detection effect is good,the three degree of geological body with irregular shapes,such as bad geology karst,underground river detection effect is poor;and the geological radar method of short distance detection precision is high,the water filling,mud,cavity and irregular geological body three degrees(cave,underground river)to detect the effect of good.According to the engineering geological data of the geological radar method by using the TSP method and the long and short forecast forecast combination of surface structure prediction and irregular geological prediction model of combining to the specific location and characteristics of tunnel geological disasters were accurate and reliable prediction,prediction results can meet the requirements for the construction safety of karst tunnel.