Impact Analysis Of Foundation Excavation On The Embankment Stability Under Dynamic Loading

The new bridge pier foundation pit is located within the protection range of Railway Subgrade,excavation of the foundation pit will have certain influence on the railway,the dynamic load of the existing railway aggravates the bad influence.In order to ensure the safety of the adjacent railway,in the process of foundation pit excavation in the toe of the embankment,it is necessary to study this problem.In this paper,based on the foundation of the bridge pier cap rock of the super long bridge,the main work is as follows:First of all,the support structure of the foundation pit of the 165# pier cap of the sun crossing bridge is designed,and the related soil layer and structure parameters are obtained through field investigation;then the finite element software MIDAS NX is used to analyze the influence of the foundation pit excavation under the dynamic load of the train on the settlement of the track and the displacement of the retaining pile,it is pointed out that the control measures of 60km/h and 40km/h in the process of foundation pit excavation are limited Based on the deformation control standard of railway subgrade;the comparative analysis of the different conditions of the train(bus 60km/h,90km/h,120km/h,40km/h,60km/h,van 80km/h)and different supporting methods(piles,pile anchor)dynamic response of level and vertical to the embankment in different depth during the excavation of foundation pit excavation adjacent to existing lines(0m,2m,under 4m,5.8m);Finally,based on the dynamic response analysis,the static and dynamic stress ratio is calculated by Li,the main calculation steps of the cumulative plastic deformation of the dynamic load of the train after the excavation of the foundation pit are given,and the cumulative plastic deformation of embankment under cyclic loading is predicted.