The Research Of The Inside-pit’ Impact On The Out-side-pit’ Supporting Structure In The Pit-in-pit’ Pit

Since more than30years since reform and opening up, the cities are becomingmore and more enormous with the rapid development of China’s economy.The use ofthe big cities’ground is close to saturation.So the use of the big cities’underground isvery important for the cities’sustainable development and improvement of the citiesfunction in Twenty-first Century.In the development of underground space,we mustface a problem,the soil supporting problem.Foundation pit engineering is to solve thisproblem.During the construction of foundation pit,the builders often excavate twotimes or even several times in the big foundation pit due to the need to lift wells,infrastructure or other required reserve forward interface of undergroundengineering.It is called pit-in-pit.If the inside-pit is close to the outside-pit and thedesigners ignore the influence of the inside-pit,the inside-pit will cause the outside-pit’supporting structure failure.This article first discusses the calculation problem of the finite soil’passive earthpressure and the active earth pressure, then analyzes the effect of the distance betweenthe inside-pit and outside-pit on the outside pit’support deformation.It simulates theexcavation of the pit-in-pit by ABAQUS.It gets the information of the supportingstructure form the ABAQUS.Then It analyzes the effect of the distance between theinside-pit and the outside-pit and the depth of inside-pit on the outside-pit’supportingstructure deformation.At last，it calculate a practical example.