Dynamic Analysis Of Subway Steel Spring Floating Slab Track And Research On Tunnel Non-uniform Settlement

Metro train running on the track is a complex process. This paper constructed train-steel spring floating slab track-tunnel-foundation two-dimensional coupled dynamic analysis model to analyze the interaction between metro train, subway track, tunnel and the foundation systematically. This is the first time simulating the constraint of the side of the floating plate board by shear hinge with both bending units and shearing units. Analyzing the influence of parameters of model structure and external incentives on the dynamic response of rail and train by numerically solving approach. Compared the solving results with the subway tunnel vibration acceleration field testing results. Finally, considered the effect of tunnel uneven settlement on the dynamic analysis model. The main researches and innovations are as follows.(1) Simplified the track layers with three different beam theories according to theirs structural features. Obtained reaction coefficient between Groundwork tunnel and surrounding soil by referencing pile soil reaction force calculation method and Novak plane strain theory. At the same time, this paper considered the stiffness reduction on tunnel. The model can simulate real subway tunnel structure state better.(2) Calculated train and track dynamic responses with various parameters of support member (steel fastener and spring). Combined with track gauge deformation requirements and considered the state of track vibration state and vibration isolation performance, this paper obtained optimal parameters of fasteners and steel spring value.(3) The shearing unit can effectively reduce the displacement of the plate end, but poorly to reduce the floating slab deformation. The bending unit can improve the overall stiffness of the floating board performance, but reduce plate end displacement negatively. Both units has a complementary role to enhance the overall performance of the floating slab. Based on statistical analysis of the dynamic response of the rail car, this paper got the optimal parameters of both units.(4) Measured floating slab vibration acceleration of Hangzhou Metro Line 1. The testing results show that, floating slab track has vibration isolation effect, the Shear hinge can resist deformation of the corner of the end plate.(5) Analyzed the calculation results of train-rail system under differential settlement conditions, found that uneven settlement occurs in the plate end position more badly than occurs in the plate middle position. The train can meet the safety and ride comfort requirements under normal operating speed with all kinds of uneven settlement parameters. Further to analyze the influences of uneven settlement on high speed tunnel, obtained high speed tunnel settlement limit value.