| Steel Sheet Pile cofferdam has the advantages of high strength,flexible construction,economic applicability,etc.it has been widely used in underwater foundation construction of bridges in China,especially in the construction of bridge foundation with small plane size of bearing platform,shallow water depth and slow velocity.With the increase of construction depth of steel sheet pile cofferdam for bridge foundation,the length of Steel Sheet Pile increases again and again.However,due to the strength and rigidity of steel sheet piles,Steel Sheet Pile Cofferdams can not be used in large-scale construction in water depth of more than10 m.Therefore,it is of great significance to enhance the design and construction quality of the Steel Sheet Pile Cofferdam and ensure the safety of the cofferdam construction to strengthen the research on the ultra long steel sheet pile cofferdam for deep water foundation.The main work of this paper is as follows:(1)In this paper,the layout plan,the vertical spacing and the waling are studied,and the optimization methods based on different objectives are put forward,and the vertical spacing ratio values of different number of internal bracing are given.(2)Relying on the foundation construction of Mangdaohe super large bridge of the north-south highway connection project of Wufengshan river crossing passage,this paper studies a kind of underwater integral installation and removal technology of the inner support of the enclosure,and compares the improved process with the conventional construction process,determines the key working conditions of each,and analyzes the stress characteristics of Steel Sheet Pile Cofferdams under different construction processes through the method of modeling analysis The characteristics of the two construction processes are summarized.(3)The paper analyzes and discusses the problem that the adjacent Steel Sheet Piles do not have enough connection degree and there is staggered movement after driving,which results in the decline of bending resistance and water load resistance of Steel Sheet Piles.A comparative model of Steel Sheet Pile Cofferdams is established.The results of deformation and internal force of cofferdams under different modeling methods are compared,and the reasonable modeling method is discussed based on the measured data.(4)Relying on the deep-water foundation construction project of mangdaohe super bridge,an intelligent monitoring system for deep-water foundation construction is developed,which makes up for the short board of traditional construction monitoring in the implementation process and improves the efficiency and quality of construction monitoring.The system has been successfully applied to the foundation construction of mangdaohe bridge,and the superiority of the system has been verified through the analysis of the construction monitoring results.(5)Limited by the strength of steel sheet pile,construction machinery and other reasons,at present,the application of Steel Sheet Pile in China is basically in the situation where the maximum head difference is not more than 15 m.Therefore,in this paper,combined with the practice and research results of the Steel Sheet Pile Cofferdam of the mangdaohe super large bridge,the relevant design and construction suggestions are given. |
PDF Full Text Request