Analysis On Lining Vibration Response And Damage Of Underground Highway Tunnel Under Load Effect Of Train Passing Through

It has become an important way to cross the existing high-speed railway through the tunnel.At present,we can safely complete the construction of the underpass tunnel under the high-speed operation of the train.However,the long-term vibration load generated by the high-speed train during the operation period will have a negative impact on the underpass tunnel structure.This paper mainly studies the impact of vibration load on the underpass tunnel during the operation of high-speed train.Based on a high-speed railway project in Chongqing,the numerical simulation method is used to systematically study the vibration response characteristics and damage distribution development law of the underpass tunnel lining under the vibration load of high-speed train.The main research contents are as follows:(1)The three-dimensional refined dynamic analysis model of subgrade underpass tunnel of high-speed railway is established by using the large-scale general finite element software ABAQUS,and the vibration response law of tunnel under the two traffic modes of train double line passing and single line running is analyzed systematically.The results show that the vibration load produced by the high-speed train has the greatest impact on the tunnel intersection.With the increase of the distance from the intersection,the impact of the train vibration load on the tunnel decreases gradually.(2)Based on the damage theory and the concrete plastic damage model,the damage distribution law of tunnel lining under the two traffic modes of train double line passing and single line running is analyzed systematically.The results show that the train load will increase the damage value of the initial damage element,and it can not be recovered,but it will not increase the number of damage elements.(3)By analyzing the vertical displacement of the tunnel and the increment of the dynamic response of the maximum principal stress of the lining under the action of the train load,the influence of the train running speed,the intersection angle between the tunnel and the railway,the distance between the tunnel vault and the track top on the vibration response from the underpass is studied,and the influence law of each influencing factor is obtained.(4)The sensitivity analysis method is used to analyze the train speed,the intersection angle between the tunnel and the railway,and the distance between the tunnel vault and the track top.The sensitivity factors of each influencing factor are calculated to compare the influence degree of each factor on the vibration response of the tunnel lining.