The Tunnel Collapse Monitoring And Alert Technology Research

As China continues to increaseinvestment in the transportation infrastructure in recent years,a large number of highway tunnel projectsare constructing,but tunnel collapse accident sometimes occurred because of the complex construction of the tunnel engineering,the otherness of geology and other factors.The proposed of NATM madetunnel collapse monitoring an important part of the tunnel project.However,the traditionalmethodsoftunnel collapse monitoring and alerting technology has some limitations.In this paper,combiningwith the background of GreatLion Mountaintunnelengineering,undertook the optimal analysis of tunnel collapse monitoring displacement,and exploreda new technology about the early alert of tunnel collapse.That is advanced in the methods,and it can provide reference for similar research and engineering practices.In this paper,based on the displacement monitoring data of Great Lion Mountaintunnel,usedFLAC3D-PSO-GPR collaborative optimization algorithm to analyzethe mechanical parameters of surroundingrockof the first cross section.This method has a high degree of intelligence,demonstrating accuracy and efficiency.Firstly,based on the inversion of surrounding rock mechanics parameters,usedFLAC3 D to calculate the whole excavation process of displacement curve of surrounding rock,which including the loss displacement.The calculation displacement curve and translational monitoringdisplacement curve fit with a high precision.Analysis showed that the loss displacement accounted for a high proportion of convergence displacement and can't be ignored.Using the calculation displacement curve as real displacement curve of surrounding rock has important reference significance for stability evaluation and tunnel construction safety assessment.In addition,this paper also analyzed the technology of tunnel collapse alerts.Firstly,the paperanalyzedthegenerallydisplacement variation of surrounding rock,and summarized the collapse alert indicators,and determined the reasonable alert indicators.Then,in this paper,based on the inversion of the mechanics parameters of surrounding rock of the first cross section,used the difference method to correct those parameters,operating FLAC3 D to numerically simulate the analysis model which correspond to the third cross section,calculating the displacement curve of surrounding rock during tunnel excavation,and referencing materials at home and abroad,identifying the dynamic alarm value of tunnel collapse which adapt tothe monitor working conditions.And classifiedthe alarm values,in order to grade the alert.In addition,this paper based on thistunnelcollapsemonitoring project of Great Lion Mountain,with the use of remote telemetry technology,establishing a unattended,automatic acquired,and automatic alerttunnel collapse alert system.The alert technology research of this paper has a high applicability and certain advantages,and showed good resultsin practice when applied to large collapse alert in the Great Lion Mountaintunnel.