The Application Of Bored Pile And Cement-soil Mixing Pile Supporting System In The Support Of Soft Soil Foundation Pit

The development of city construction has greatly promoted the development andutilization of underground space resources. In the construction process of Underground rail,large-scale market and Garage, the scale, depth and difficulty of foundation pit engineeringconstantly being refreshed, it means that the foundation pit engineering is facing newcontents and challenges. In particular, soft soil deep foundation pit is the current hot anddifficult problem in geotechnical engineering. In the city of high land price, how to solvethe two key problems of soil retaining and water seal, how to select the reasonablesupporting schemes, ensuring foundation pit engineering safe and economical, is a subjectthat people have been exploring.This paper, combined with an engineering example in Tianjin area, focuses on boredpile and cement-soil mixing pile supporting system to carry out the analysis of theory andpractice. The main research work can be summarized as follows:1. Research and access to relevant information at home and abroad, summarizing thepresent situation of research at home and abroad on the subject.2. The main features of deformation and the mode, cause and mechanism of instabilityof soft soil foundation pit are studied. The result shows that the most main cause ofinstability of soft soil foundation pit is large deformation, which is of essential guidingsignificance to propose solutions of projects and analysis of the advantages anddisadvantages of various soft soil foundation supporting methods.3. Describing the mechanism and advantages and disadvantages of foundation fitsupporting structure common used in soft soil area, on this base, brings up the someproblems needing attention in soft soil foundation pit supporting selection.4. Systematically expounding and analyzing the design and construction of bored pilesand cement-soil mixing piles, brings up that paying particular attention to strengthen thecontrol of construction quality of bored piles and cement-soil mixing pile during theconstruction process.5. Combining the specific examples of projects in Tianjin, uses the retaining walls ofdeep excavation calculation software FRWS of Tongji Venus. Determine the depth ofsupporting piles embedded mainly through the anti-overturning safety and security of theoverall stability of foundation pit. Based on this calculation, checks the soil anti-heave in the bottom of foundation pit using the stability analysis theory of the second chapter. Theresults shows that the overall stability, anti-overturning stability and anti-heave safety factorof the foundation pit meets the specification requirement.In summary, Using the good sealing performance of cement-soil mixing pile and soilprofiles of bored pile together in foundation pit support of coastal soft soil area can achievegood results. The demonstration of this paper enriches the engineering applicationexperience of bored pile and cement-soil mixing pile supporting system. It can providereference for similar projects and also provide valuable experience for the promotion ofsupporting structure.