Analysis On Mechanical Influence Of Adjacent Construction Of Metro Shield Tunnel On Existing Bridge Pile Foundation

With the rapid development of urban modernization and the rapid development o f urban rail transit system,more and more engineering cases of bridge pile construction in metro shield tunnel are near,and the influence of subway shield tunnel construction on pile foundation has gradually become a hot topic in engineering and theoretical research.Because the shield construction will disturb the stratum,it causes the additional internal force and deformation of the bridge pile foundation.When the shield tunnel near the bridge pile foundation construction,it has more influence on the pile foundation,and the security risk is greater.Therefore,it is an important content to study the influence law of shield tunnel on pile foundation mechanical behavior when it is close to bridge pile construction,and it is an important content to study the influence of shield tunneling on pile foundation.In this paper,the influence of the mechanical behavior of the pile foundation on the pile foundation in the near side of the shield tunnel of Guangzhou Metro Line 6 is studied.First,the influence of the near construction of the shield tunnel on the vertical mechanical behavior of the pile foundation is analyzed based on the Loganathan solution and the load transfer method.On this basis,the Mindlin solution and the elastic foundation beam are based on this basis.The theory further analyzes the influence on the horizontal mechanical behavior of the pile foundation.Then,the influence of the pile foundation in the construction process is simulated and analyzed by the FLAC3 D software,and the numerical simulation results are coMPared with the theoretical calculation results.Finally,the field monitoring data are analyzed,and the results are simulated with the numerical simulation results.The results of theoretical calculation are coMPared and verified.The main contents of this paper are as follows:(1)Investigate the research results of shield tunneling near pile foundation at home and abroad.The main analysis method and the influence law are summed up,and the main factors affecting the mechanical behavior of the pile foundation are clarified.On this basis,the technical route of combining theoretical analysis,numerical simulation analysis and field monitoring analysis is put forward.(2)Analyze the influence of shield tunnel adjacent construction on vertical mechanical behavior of pile foundation.By using the two stage analysis method,the settlement of the pile caused by the shield construction is calculated by Loganathan analytical solution,and the pile body is added to the pile.Then the vertical mechanical response of the pile foundation is analyzed by the load transfer method.Finally,the horizontal horizontal distance between the pile foundation and the shield tunnel and the vertical settlement of the pile foundation under the buried depth of the shield tunnel are studied.The effect of deformation.(3)Study the influence of shield tunneling on the horizontal mechanical behavior of pile foundation.First,based on the Mindlin solution,a mechanical model is established to calculate the additional horizontal load on the near pile foundation with three kinds of construction loads,such as shield earth pressure,shield shell friction and grouting pressure.On this basis,the horizontal mechanical behavior response of pile foundation under additional horizontal load is analyzed by the elastic foundation beam theory,and the pile foundation is studied.The horizontal horizontal distance between the shield tunnel and the length of the pile affects the lateral deflection of the pile foundation.(4)The 3D solid model is established by FLAC3 D software,and the construction process of the shield near side is simulated.The influence of the shield construction on the pile foundation is analyzed,and the results are coMPared with the theoretical calculation results.Finally,the field monitoring data are arranged and analyzed,and the results are coMPared with the numerical simulation and theoretical calculation results to verify the accuracy of the numerical simulation results and the rationality o f the theoretical calculation and analysis methods.