Study On Settlement Of Foundation With Silt Induced By Shield Constuction And Train Load

Zhengzhou is an important city of central China, the rapid development of the city hasbrought great pressure to the city traffic. The subway is known as the fundamental way tosettle the problem. The shield driving has become an important construction method due to itsunique advantage in the process of subway construction. Zhengzhou is located in the areasformerly flooded by the Huanghe River, with a deep silt layer which has a certain bearingcapacity, and with the high compression. Hence, there are many complex problems buildsubway in the strate. And it’s easy to take place settlement of a wide range of phenomenaeven liquefaction under the action of the vibration. So, it’s important to study on theregulation of soil settlement and subway foundation displacement after the operation duringthe shield construction in Zhengzhou subway.This paper takes the Zhengzhou No．1Subway Line as an example. The model of shieldconstruction was established with the help of finite-element software MIDAS/GTScombination with the silt layer characteristics of this region. In this model deformation of theexcavation and numerical simulation analysis of soil deformation caused by shieldconstruction law were studied. The impact of factors such as soil deformation axis depth,grouting effect，Jacking force shield and soil strength were analyzed. At the last of this paper,some meaningful conclusions were obtained.Soils of plastic settlement induced by train load which was simplified according to somerelevant regulations of subway and rail design was studied. And this paper also analysis theregulation of soil settlement under different tunnel depth and strength of soil.The analogue of train load is based on the foundation of former research, according to theload expression obtained with the parameter of the subway, the displacement field around thetunnel is calculated using the MIDAS/GTS finite-element software in different speed anddifferent modulus of compressibility．And based on the result of numerical calculation，theposts settlement of the tunnel under the dynamic load of the train is forecasted by theexponential curve method．At the last, make a comparative analysis in details of staticsimulation method and dynamic analysis with the result of static calculation only responsethe elastic-plastic settlement under train load, we can not only analysis soil settlement whichunder train load in details of static simulation method, dynamic analysis is necessary.