| With the large-scale construction of high speed railway and highway in China,more and more tunnels are built in complex geological areas,more and more long tunnels have been built,and the difficulty of tunnel construction is becoming more and more difficult.Geological problems in large-scale infrastructure construction,especially in high-speed railways and highway tunnels,are often the key to determining the success or failure of projects.TSP system is widely used in tunnel engineering all over the world with the advantages of long prediction distance,relatively simple operation and safety,short construction time,small interference in construction,high accuracy and high accuracy.Through the TSP ahead prediction,the location,production and the integrity and water content of the surrounding rock structure in front of the tunnel face are discovered in time,and the information is provided in time to prevent the possible Catastrophic accident such as the tunnel water inrush,the mud gushing and the gas inrush,so the tunnel ahead geological forecast is of great social and economic benefits for the safety scientific construction,Improving the construction efficiency,shortening the construction period and avoiding accidents.However,at present,the interpretation of bad geological bodies by TSP lacks a clear interpretation sign,which is more dependent on experience and can not reduce the possibility of multi solution,and the prediction accuracy is low.Therefore,the current technology needs further improvement in theoretical analysis,data acquisition,prediction accuracy and reliability.In this paper,based on the scientific and technological project of《tunnel excavation and restrictive water drainage technology under high water level》,takes the project of Xiao Bei Shan Tunnel of the Jie(Yang)Hui(LAI)Expressway in Guangdong Province as the research background,we studies the application technology of the advanced geological prediction of the tunnel TSP under complex geological conditions,introduces the basic original,field working method and data processing flow of the TSP method.And effective methods to improve prediction accuracy are discussed.The main conclusions are as follow:(1)The parameter values of each attribute of rock obtained by the method of seismic wave reflection wave by the TSP method can quickly and accurately locate the position,size and occurrence of the bad geological body in front of the ]tunnel face.A large number of engineering practices show that the TSP system has obvious applicability and effectiveness in the detection of unfavorable geological bodies such as karst and fault fracture zones.(2)The basic theory of seismic wave propagation is introduced from the relation between the stress and strain of the homogeneous medium and the equation of the longitudinal and transverse wave motion.On the basis of this,the basic principle of the tunnel seismic reflection wave method is introduced,and the reflection wave time distance curve equation with single horizontal interface,single inclined interface and multiple parallel interfaces are derived by using the geometric method.(3)A set of TSP measurement and observation system is set up,the accurate data acquisition method of field data is put forward,and the data processing methods such as bandpass filter parameters and anti Q filtering are adjusted.The prediction accuracy of the TSP system is effectively improved.(4)Taking TSP as the basic method,Comprehensive use of engineering geological survey,geological radar,infrared water detection and other means,and the combination of geological survey and geophysical prospecting,long distance and short distance,seismic method and electromagnetic method can greatly improve the accuracy of the single prediction method... |
