Study Of Influence On Deformations And Stresses Of Metro Shield Tunnel Crossing Underneath High-speed Rail

In the21st century, with the rapid development of city mass transit and high speed railway, the metro crossing high speed railway engineering appears constantly. Therefore, before the construction of the metro shield tunnel crossing high-speed railway, the maximum deformation and stress of strata, embankment and track induced by tunnel excavation are predicted, the law of deformation and stress of structures are studied, the appropriate control measures of shield tunnel crossing high speed railway are proposed, these have very important practical significance for metro shield tunnel crossing existing high-speed railway engineering.This paper based on the practical engineering background, the finite element software is used to simulate the dynamic construction process of subway shield tunnel crossing high-speed railway. Through the methods of theoretical analysis and numerical simulation, the deformations and stresses influencing degree and regularity of strata, embankment and track which are caused by lots of factors on the subway construction including geological conditions, subway depth, double-line horizontal spacing and shield construction parameters(grouting effect, grouting pressure and the thrust of tunnel face) are studied. The control standards and key control measures are put forward on the subway shield crossing high-speed railway of embankment type.This paper studies the following four aspects:Firstly, this paper expounds the influences of high-speed railway due to shield tunneling construction is a dynamic process and is also a interaction course of metro, strata and high speed railway. A comprehensive system of multiple structure, multiple factors which contains subway shield and stratum soil and high-speed railway is put forward. A new balance is built up through the interaction of all structures finally.Secondly, through establishing a three-dimensional finite element model, the deformations and stresses influence regularity of strata, embankment and track which are caused by six factors on the metro construction including geological conditions, subway depth, double-line horizontal spacing, grouting effect, grouting pressure and the thrust of tunnel face are studied. The qualitative relationships in reference to these factors with the deformations and stresses are put forward.Thirdly, based on the related specification and the research content of this paper, the propositional control standards are put forward on the metro shield crossing high-speed railway of embankment type.Finally, the key control measures which are considered from influence sources, propagation paths and protection objects are put forward on the metro shield crossing high-speed railway of embankment type. Through the numerical calculation analysis the effectiveness of the three aspects of the control measures to the high-speed railway’s deformations and stresses control.