Study On Disturbance Of Subway Tunnel Construction And Its Effect On The Bridge Pier And Line Of The Adjacent High-speed Railway

Recently,there are rapid development in infrastructure industry in China.Among them,high-speed railway,subway,etc.as the representative of the infrastructure construction rapidly carried out in the major cities,greatly enhanced the efficiency of logistics and transportation.At the same time,the conflict in the space of different buildings(structures)were bound to be brought and there is a great challenge if the existing buildings are very sensitive to disturbance.Among which subway tunnel near the high-speed railway is a typical representative of this type of research topics.In order to ensure the smoothness of high-speed railway,viaduct foundation form were applied in a considerable proportion of high-speed railways.For the problem of tunnel closely crossing which involving complex linkage effect of tunnel,bridge and track on which the main line of the thesis is based.The deformation of the strata caused by tunnel excavation is firstly studied in this paper.The influence of soil physical and mechanical properties on formation deformation is analyzed by using soil test,numerical analysis and site monitoring.The results show:the influence of soil mechanics parameters on formation deformation could not be neglected under the conditions of large deformation.And the influence of the tunnel crossing the bridge pile on the bearing capacity of the pile was further studied.The results show:considering the change of soil mechanics parameters,there is a significant difference between the calculation results of the bearing capacity of the pile in the case of severe disturbance of the soil.The influence of tunnel excavation on the deformation of bridge piles is studied.Applying the method of shear displacement method,the finite difference method is used to calculate the settlement of single pile caused by tunnel excavation in heterogeneous soil,the average settlement of group pile can be obtained by using the theory of"reciprocal piers".The settlement of pile foundation is calculated according to the formation loss rate corresponding to different shield parameters in practical engineering analysis.The mapping relationship between the additional deformation of the bridge foundation and the additional deformation of the track is obtained through theoretical analysis.Combined with high-speed railway design specifications for high-speed railway bridge structure deformation and axle coupling dynamic response control requirements,track irregularity control standard is obtained and piers allow deformation control values is inverted accordingly.The bridge settlement monitoring results are in line with the expected calculation according to the allowable control value of the pier to choose a reasonable shield parameters for construction.