The Stability And Prediction Of The Underground Corridor In Wuhan

With the development of Chinese economy,urban population is increasing,and how to make good use of the urban space becomes an important issue.In the development of all major cities,high rises,subway and underground shopping malls have become the necessary choice for the development of large cities in the country,among which the construction of subway projects and underground shopping malls belong to the category of underground engineering.In the underground engineering,the excavation of the foundation pit is a problem that every underground project will face.This paper has carried out careful investigation for engineering geological condition taking a pedestrian street corridor underground excavation in Wuhan as the research background.It mainly includes: topography,lithology,geological structure,hydrogeological conditions and weather conditions,etc.Meanwhile,the sample of soil has also been carried out and the physical properties are also tested.Based on the physical properties,the paper also analyzed the advantages and disadvantages of the Rankine earth pressure theory and Coulomb earth pressure in order to lay a good foundation for the subsequent analysis.Then,combined with these 2 theories,the paper analyzed the stability of the foundation pit based on the stability calculation.The result proves that the stability of the foundation pit can meet the standard.However,the simple calculation theory can't reflect the displacement and stress distribution of the foundation pit in the excavation accurately and fully.Therefore,based on the research mentioned above,this paper used FLAC3 D to make a detailed calculation for stress distribution and transformation in the excavation of the foundation pit.This kind of calculation is different from the finite element analysis method,that is,the simulation process is based on the difference method,and it can solve the stability of foundation pit.Numerical simulation is at the scene of the accurate exploration results and the soil mechanics parameter.The results are as following:(1)A numerical simulation analysis for foundation pit without supporting structure was made,and it's found the deformation of foundation pit walls is larger,which can significantly influence the stability of the foundation pit deformation.(2)The influence of the stability of the reinforced concrete supporting of foundation pit wall was analyzed,and.we focuses on the effect of section size of foundation pit.It is found in the reinforced concrete support structure under the condition of invariable,the effect of increasing the size of concrete support of is small,and when making the structure design of supporting in the foundation pit,the size of the concrete support shouldn't be increased to improve its stability.The calculation results can provide guidance for the later construction and safety operation of foundation pit engineering.Also this work can lay a good foundation for the later engineering.