Study On The Influence Of High-speed Train Vibration Load On The Safety Of Adjacent Tunnel Structure

With the development of economic and technological conditions,China’s traffic network is becoming more and more perfect.Major cities are committed to building a modern three-dimensional traffic system,and the proportion of tunnel mileage in new projects is also gradually increasing.As a result,it is inevitable that the new highway,municipal,subway tunnel and high-speed railway tunnel are close to each other,including the upper span,the lower crossing,overlapping,parallel,crossover,etc.,and the number of such projects is also increasing.The dynamic response law and structural safety of these adjacent tunnel structures under high-speed train load have become the focus of attention.Taking Wuwu tunnel of Hangzhou-Wenzhou High-speed Railway and Xizhenshan Tunnel of Yidong High-speed Railway as engineering background,this paper conducts in-depth research on dynamic response law and structural safety of tunnel crossing section by theoretical analysis and numerical simulation.The main research contents and results are as follows:(1)Taking the three-dimensional cross structure of upper span high-speed railway tunnel and double hole large section highway tunnel as the research object,the three-dimensional dynamic calculation model of train dynamic load-surrounding rock-structure is established,and the dynamic response law of tunnel structure under the condition of one-way passing and two-way meeting of high-speed railway is studied,and the response degree of important indexes such as acceleration,displacement and stress of cross tunnel structure and the change law of structural safety under the two passing modes are compared and analyzed.(2)Considering the motor vehicle load of the underpass highway tunnel,the dynamic response and safety change law of the cross tunnel structure under the action of single motor vehicle load,high-speed railway and motor vehicle combined load are studied respectively.The results show that the motor vehicle load of the highway tunnel has little impact on the adjacent tunnels in the intersection area,and the two-way passing of the high-speed railway tunnel has a more adverse impact on the safety of the highway tunnel structure than other passing modes.(3)The influence of train speed,surrounding rock grade,tunnel clearance and other factors on the acceleration,displacement and structural safety of highway tunnels in the cross area under the condition of two-way meeting of high-speed rail trains is studied,and the impact zoning of high-speed rail driving on highway tunnels is divided based on the vertical acceleration.(4)Using the plastic damage constitutive model of concrete,by considering the deterioration degree of highway tunnel lining structure during operation,the distribution law and influencing factors of highway tunnel structure damage and development in the intersection area during operation under the load of high-speed railway train are studied,and the weak position of highway tunnel structure damage and deterioration during operation is identified.