Analysis Of Construction Status And Control Strategy Of Metro Shield Tunneling Through Urban Viaduct

Today,all lifestyles in our country are developing rapidly,and with the continuous growth of the city’s population and the continuous expansion of the city’s scale,all kinds of construction require the use of limited urban space.will do.However,space on the ground is always limited.The existing above-ground space is far from meeting the needs of active urban development,and with the increasing demand for space,the development and utilization of underground space has become a general trend.It seems that more and more cities are now planning or starting to build subways,and as single-track construction cannot meet the travel needs of citizens,so is subway construction.In the process of developing and utilizing underground spaces,especially in the construction of subway roads,shield construction is gradually becoming mainstream.However,since this method can have a significant impact on existing structures and pile foundations,how to reduce land subsidence and reduce the impact on adjacent pile foundations is an urgent matter in engineering.This is an issue.Therefore,it is very important in practice to study the effect of subway shield structures on the surface of the earth and the foundations of bridges.In this paper,we mainly used MIDAS GTS NX finite element numerical simulation software and obtained it from numerical simulation with the Shenyang Subway Line 10 project under the shield section of Kawajiji Station under the urban viaduct as the engineering background.Combine the data with the resulting data.From the actual field survey.A detailed discussion of the various impacts and impacts of the tunnel construction process carried out by the method,the shield method on urban structures under various drilling conditions.In this regard,the following research work was mainly carried out.(1)Summarize the current situation of domestic and foreign experts and scholars regarding the surrounding land subsidence and bridge deformation during shield construction.Combined with the Beidaying Street tunnel drilling project,we will give you a brief overview of the project,hydrogeological conditions and the shield machine construction process.(2)We will briefly introduce the method of collecting and analyzing monitoring data for land subsidence,bridge subsidence,and displacement at actual construction sites.Based on this analysis,surface subsidence and bridge deformation curves are drawn to give a general rule of shield excavation and bridge deformation.(3)Using MIDAS GTS NX finite element numerical simulation software,establish a 3D finite model and analyze the ground subsidence and bridge deformation of the shield tunnel under the adjacent pile foundation at each stage of construction.Based on this,we analyze the different effects produced under different conditions in different basic environments,such as the modulus of elasticity and internal friction of the soil layer,the thickness of the shield tunnel overload,and the modulus of elasticity of the lining segment concrete.To do.etc.Impact of land subsidence;Impact of different tunnel pressures,jacking forces and grout pressures on viaduct pile foundations.Therefore,it can be used as a basis for optimizing plans in the construction process.(4)It is possible to obtain a demonstration that can optimize the original design scheme by performing analysis by combining model simulation data obtained by changing various construction conditions and parameters with actual measurement data obtained in an actual project.I can do it.Use the MIDAS GTS NX finite element numerical simulation software to rebuild the model based on the relevant parameters of the optimized scheme and obtain relevant data on post-optimized surface subsidence and bridge deformation.Data and analysis obtained before and after the comparison confirmed that the optimized scheme was effective for surface subsidence,and the problem of bridge deformation was improved to some extent.Analysis and comparison of planning parameters before and after optimization shows that optimized planning speeds up construction to some extent,reduces project costs,and has certain effects on optimizing shield construction.