Analysis Of The Influence Of Subway Shield Tunneling On Adjacents Pile Foundation

In order to alleviate the pressure of urban ground traffic, there will be a large-scalesubway transit construction period in many cities during the Twelfth Five-year Plan.Due to the subway tunnels always locate in the area of crowded with city buildings, andalso most buildings are in the form of pile foundation, sometimes shield tunnel willdrive through adjacent to pile foundations, the shield construction will effect the internalforce and deformation of pile foundations, and even the stability and the safety ofstructure will be produced a certain degree of loss. Therefore, in order to protect theupper structure and to ensure tunnel construction smoothly, the study to research theeffects of tunneling on adjacent pile foundations has important practical significance.Combined with a similar project during the construction of Guang-Fo rail line, thispaper will study the subject from the following aspects.（1） In order to establish the numerical models to simulate the dynamic in theconstruction of shield excavation, installation lining, grouting process to simulate thedynamic in the construction of shield excavations, installation lining, grouting processand so on, first introduce the technological characteristics of the shield tunnelingconstruction to provide the theory basis. And also introduce two methods ‘engineeringanalysis and theoretical analysis method’ to calculate the settlement of pile foundationcaused by shield construction. Through the existing theory, this paper will analyses theadvantages and shortcomings of the two methods of calculation, and in the subsequentanalysis.（2） This paper will use finite difference software—FLAC^3Dto establish3D models,after testing and verifying the constitutive model is reasonable, this paper considersmain influence parameters such as different load of top pile, different distance betweenpile and hole, different pile length, different pile diameters, then analysis and summarythe low of influences of stress and strain caused by shield dynamic construction. （3）Combined with a project example that shield passes through a pile foundation ofresidential building, then this paper will estimate the security and stability of thebuilding and analysis the influences of stress and strain caused by shield dynamicconstruction to find the biggest impact of pile foundation during the construction stage,and this paper will provide some basis in protecting and evaluating buildings duringsome similar projects. At the same time, the results of numerical analysis andengineering calculation analysis results are verified by contrast.