The Study About Dynamic Response Of Underground Tunnels And On The Surrounding Environment Impact Assessment Study Basing On Train - Tunnel Coupled System

At present the study of the vehicle, tunnel, and the interaction between the two dynamic problems are still small. However, in recent years, Metro Rail Transit in China were vigorously used, so to carry out vehicle - tunnel under the subway tunnel coupled dynamic response analysis and assessment of the impact on the surrounding environment research has important practical significance.In this paper, giving full consideration to the vehicle- tunnel whole system, then establishing the vehicle model and the road model to analyses the dynamic coupling of vehicle and tunnel,the main analysis are summarized as follows:①Consided the body vertical vibration, vertical vibration of a suspension and wheel under vertical vibration of the vehicle vibration model was established and vibration equation. Vehicle and track through the compatibility condition of displacement, and discrete equations of the vehicle's orbit - the tunnel linking the vibration equation of form reflecting the vehicle - track the systematic coupling model and equations.②Developed a numerical simulation program for vehicle- tunnel coupled dynamic analysis. Relationship running from a vehicle matching the quality of the starting level of the surrounding rock, the track structure type, the type section of the tunnel and the subway cars and other changes in the operating speed of different working conditions, a great deal of calculation and analysis, analysis of changes in system parameters Body vertical vibration acceleration, vehicle dynamic wheel weight, wheel load reduction rate, the rail vertical displacement, vertical displacement of surrounding rock at the top of the tunnel surrounding rock at the top of the vertical stress of the different evaluation.③The study found that: 1)Tunnel level under the same conditions of vehicles traveling the indicators of the impact is very small, in which the vertical body acceleration, dynamic wheel weight, wheel load reduction rate as the surrounding rock by a good variation and decreases, while Rail vertical displacement, vertical displacement of subgrade, subgrade vertical stress variation with the rock gradually increased from the good, you can determine when the train is moving around inside the tunnel rockⅢlevel, the indicators more reasonable; 2)Obtained by comparing the embedded Ballastless sleeper cushion with elastic and rubber boots and other multi-sets of elastic material, can play a good effect of vibration and noise reduction, better than the sleeper buried ballastless track Trends; 3)Board in the track under the same type, orbital plate stiffness on the contribution of various indicators of the vehicle is not running, by the blind to improve rigidity to improve the rail tunnel is not desirable mechanical properties; 4)Analysis also showed that , select the type of tunnel cross-section only when the construction method of tunnel construction, and when the tunnel operation, of driving the vehicle safety, comfort and little impact can be ignored; 5)Train speed of the moving vehicle safety, comfort Significantly affected, then the case of low speed, the indicators are improving as the speed increases, the change greatly, but the speed reaches a certain value, the indicators have improved with the speed but with a gradual decreasing trend; 6)Subway train running on the ground vibration at the speed of the train is moving with the load changes, and the impact is the increase with the depth of the tunnel decreases.