The Combination Of Prestressed Structural Steel And Internal Support In Foundation Pit Engineering Research

The combination of vertical support and protection structure and horizontal internal support system is one of the common support and protection systems in deep foundation trench project owing to its features of good stability,safety and reliability.As a kind of new horizontal internal support form,the combination of prestressed structural steel and internal support has the advantages of high rigidity,recycling and shortening construction period and can reduce environmental pollution and effectively cover the shortage of reinforced concrete support and single-lever support.Taking "Suwu Apartment Reconstruction and Expansion Project" foundation trench project as an example,it studies the bearing and deformation characteristics of combination of prestressed structural steel and internal support system through numerical simulation and verifies the conclusions of relevant researches by comparing them with site data.The main research content of the article is:1.Aiming at the requirements of architectural structure,project geology,hydrogeological conditions and its neighboring environmental conditions,it compares the safety,technical feasibility and economical efficiency of different kinds of foundation trench support schemes.And it finally decides to adopt the support and protection scheme of "SMW construction method + combination of prestressed structural steel and support".2.Aiming at combination system of prestressed structural steel and internal support,it proposes key points of design,calculation methods of internal force and basic layout principles.Combining "Suwu Apartment Reconstruction and Expansion Project" foundation trench project,it proposes the verification method of combination of structural steel and internal support.3.It adopts elastic-plastic non-linear finite element method,analyzes the influences of rigidity,horizontal spacing,pre-axial force and other parameters of combination of structural steel and support and optimizes the arrangement of support plane.The results show that under the precondition of ensuring the stability of foundation trench,combination system of large structural steel and support increases the area of non-support zone of foundation trench,facilitates earth excavation,shortens construction period,saves construction costs and improves economic benefits.4.It analyzes the stress and deformation characteristics of combination of prestressed structural steel and support in foundation trench project and its influences on the overall stability of foundation trench and compares analysis results and site data.The accumulated project experience has a certain of reference value for similar projects.