The Anaysis Of Affecting Factors And Optimization On The Deformation Of Deep Foundation Excavation

With the development of our country's economy, urban space has become more and more tense, underground space has gradually become an important resource. Urban land prices rising, people for the requirements of urban space utilization is constantly increasing. At the same time, because of the increasing density of urban buildings, the difficulty of excavation and supporting has tended to growing state compared to the past. All these decide and promote the continuous development of excavation and supporting technology. On the basis of ensuring security and stability, Choose reasonable and effective security excavation and support programs, meanwhile, ensuring the safety and economy of the excavation, which requires us to have a full understanding of the deformation law of excavation.In example of Yulan Dadao subway station in Hefei, combining the study of computation theory of structural stability of excavation supporting in our country and abroad, this paper studies the deformation of excavation supporting and foundation during the excavation, summarizes the main factors effecting the deformation of excavation supporting and foundation during the excavation and gives some optimization recommendations.The first part discusses the research background and significance, summarizes research status of deformation law and deformation control design calculations of excavation in our country and abroad and the major construction technology of the control of deep excavation deformation, lists the major problems for the construction of foundation pit in Hefei. On the basis of widely reading and finding documents, the second part analyzes the mechanism and main form of the deformation of deep foundation, leads to damaging form of foundation supporting, concludes the geological factors, design factors and construction factors effecting the deformation of deep foundation.In example of the foundation project of Yulan Dadao subway station in Hefei, using finite element software Midas \ GTS to establish finite element model, researching on the supporting structure of foundation and deformation of foundation bottom, the third part concludes the deformation law of supporting structure and foundation bottom uplifting in Yulan Dadao subway station. Taking different excavation widths, embedding depth of supporting structure, envelope stiffness and support positions to establish finite element model and calculate, researching on the law of the deformation of supporting structure and the uplifting of foundation bottom and determining the effect of these parameters on deformation of foundation pit when these factors are different, the fourth part gives the optimization proposal of the construction not only effectively controlling the deformation of foundation pit, but also cost savings to achieve most efficient use of resource.