Study On The Influence Of Shallow Tunnel Construction On Bridge Pile Foundation And Its Reinforcement Technology

In order to solve the ground traffic pressure,many cities are building a convenient and fast underground railway.During construction of urban subway,subway tunnel beneath the building and growing situation of municipal roads and bridges.In used shallow buried dark dug method construction is easy on formation caused disturbance,change formation stress field and displacement field of distribution,caused surface settlement,pile base occurred displacement,tunnel structure produced deformation or damage,especially not reasonable of construction method and support nursing measures,will to engineering brings huge security risk and economic loss,so research different of construction method and support nursing measures on surface sinking,and tunnel structure and the near pile base deformation of effect has important of significance.To analyze the impact of different construction methods and support measures,based on Gan hui Liao-song of the railway tunnel beneath the stone made bridge construction on the background,theoretical analysis and numerical calculation methods were used to conduct research,the following are the main contents of the paper and research results:Theory analyzes the influence of tunnel excavation on ground surface deformation patterns and characteristics of ground deformation caused by shallow-buried subsurface excavated.Research shows that construction of shallow-buried excavation tunnel of stratum deformation is mainly caused by deformation and effect both vertical settlement close to different forms of deformation of bridge pile foundations,and in accordance with established column base and the spatial relationship of the tunnel the tunnel excavation pile was classified within the line.Combined with guan hui inter-city railway tunnel through Shi Da bridge engineering,using finite element software MIDAS-GTS established three dimensional calculation model,calculation analysis steps method,and reserved core indigenous,and CD methods on surface settlement,and lining masonry structure deformation and forces,and pile base modification of effect law,last using established of criterion analysis the workers method of pros and cons,to select for this engineering of workers method. Analysis and discussion of different excavating after footage of the selected method on surface subsidence,structural deformation and internal force of lining and pile displacement effects,from the aspects of safety,economy,quick consideration by certain criteria,comparing different footage of excavation safety,so choose a reasonable excavation footage.This paper summarizes the control existing pile foundation settlement and main measures for differential settlement between piles of isolation method,grouting and underpinning law and focused application of grout-reinforcement method in engineering.According to come up with a reasonable excavation method and footage,simulation analysis of pile foundations around the range of different Grouting on deformation law of pile,combining the comparative analysis of the criteria established in this paper different scope of Grouting construction safety and economical to choose reasonable Grouting range,ensuring the safe operation of tunnels during the construction of the bridge.Combined with the Pearl River Delta inter-city rapid rail traffic Gan hui Liao song in the wire line tunnel under stone overpass project's situation,and under the current metro mining method tunnel construction experience,on existing bridge pile base grouting reinforcement and excavation of the tunnel designing and analyzing the adverse situation that may be encountered during construction,the design and construction.