The Application Of Foundation Pit Supporting Of Steel Sheet Pile And Shape-Steel Cement-Soil Mixed Pile

With the rapidly development of the foundation pit engineering in recent years,there appeared a lot technologically complex foundation pit engineering project.In addition,the scale and depth of the are becoming larger and larger,the requirement of the design and cinstruction skill of supporting structure are becoming more strict in foundation pit engineering.The success of the foundation pit engineering is determined by its safety and stability,which is important to the development of the foundation pit project.According to the construction condition and characteristics of foundation pit,there was arised a new supporting structure which consists of multiple traditional supporting structures.Take the example of the foundation pit project of wuhan qintai art museum,The paper innovatively used the mixed supporting structure of the foundation pit,which was composed of single row steel sheet pile,double row steel sheet pile,single row shape-steel cement-soil mixed pile and double row shape-steel cement-soil mixed pile.Then,explored the internal force and deformation law of each supporting structure through the results of the FEM numerical simulation of the supporting structure and the analysis of different influencing factors,then Checked the results by tianhan software and theoretical calculation.used the results of the comparison and analysis of monitoring value,simulation value and theoretical calculation value to verified the the feasibility of multiple supporting methods working in the same foundation pit.Then,introduced the recovery of the steel of the supporting structure after the foundation pit construction completed.The main contents are as follows:(1)Introduced the traditional supporting structures,earth pressure theory,calculation theory of steel sheet pile and profile steel cement soil mixing pile supporting structure.(2)According to the Technical Specification for Retaining and Protection of Building Foundation Excavations and Technique Code for Building Slope Engineering,calculated the embedmengt depth of the support structure,the overall stability of the foundation pit,the anti overturning stability of the foundation pit and the anti uplift stability of the foundation pit,then checked them by the TianHan software.Finally,the application effect of the multiple supporting structure was verified preliminarily.(3)Created the FEM numerical simulation model of foundation pit excavation,then analysed the deformation law of the horizontal displacement,bending moment and other characteristics of each supporting structure;changed the parameter value(pile length,pile diameter,etc)of the supporting structure and analysed internal force and deformation law of the supporting structure to obtain the safe and reasonable parameter value.(4)Monitored the whole process of foundation pit excavation,which can dynamic realized the deformation law of foundation pit in time,so can guide the workers do the construction with information technology.Anayled the results of the comparison of actual monitoring value and simulated value,which can objectivelyreflect the problems and shortcomings of support structure in practical application.(5)resumed the The significance of shaped steel recovery and introduced the mechanism of the shaped steel pulling out process,summarized the factors of the shaped steel recovery and the meansures of improving the rate of the shaped steel recovery,which had a good effection in the practical engineering application.The cooperative operation of the multiple supporting structure gathered the advantages of each supporting structure to resist the external forces and deformation together,which guaranteed the stability of the Foundation pit.This new supporting structure can reduce the construction difficulty,shorten the construction period,reduce the cost,show a good example and application to foundation pit engineering.