Experimental Study On Bending Mechanical Characteristics Of U-shaped Steel Sheet Pile

The steel sheet pile structure is a steel sheet pile with lock coupling devices on both sides.During construction,multiple steel sheet piles of the same specification can be connected to each other through the lock to form a continuous and tight wall structure to retain soil or water.Due to the advantages of light weight,high strength,outstanding environmental performance,convenient and fast construction,and strong durability,the steel sheet pile structure has been widely promoted and applied in practical projects.Because the U-shaped steel sheet pile wall structure is made up of multiple steel sheet piles connected to each other through the locks on both sides,this special connection makes its bending performance uncertain: when the locks between the piles are smoothly connected,each steel sheet pile participates in bending resistance alone;when there is no relative slippage between the locks of the piles,the steel sheet piles are tightly combined to form a whole to participate in bending resistance;However,in actual engineering,the connection state of the U-shaped steel sheet pile wall structure is between the above two,and changes continuously with the deformation.At present,there are relatively few studies on the bending mechanical properties of U-shaped steel sheet pile structures at home and abroad.Therefore,this paper selects the U-shaped steel sheet pile structure as the research object,designs and conducts multiple sets of mechanical tests,and conducts in-depth research and analysis on its bending mechanical properties.The main research contents of this paper are as follows:1.Designed and conducted the relevant steel sheet pile test to obtain data such as the axial deflection of the pile body,the normal strain of the cross section and the strain of the measuring point at the location of the lock;2.During the loading of the single pile,welded composite pile and single-span simply supported beam test,the growth and variation patterns of the axis deflection,cross-section normal strain and measured point strain at the location of the lock were studied and analyzed;the distribution forms of the measured point strains along the height of the cross-sections of these three tests were compared;in the single-span simply supported beam test stiffness increase interval,the variation range of the ratio of the section flexural rigidity of the single-span simply supported beam test to the section flexural rigidity of the welded composite steel sheet pile test was determined;analyzed the influence of the lock bite interaction on the bending mechanical properties of the steel sheet pile component of the single-span simply supported beam test during loading and unloading;3.A 6000 mm long composite steel sheet pile were subjected to repeated loading and unloading tests in stages(named as combined pile two-span continuous beam test).In this process,the growth and variation patterns of the pile axis deflection,crosssection normal strain,and measured point strain at the location of the lock is studied,and the influence of the lock bite interaction on the bending mechanical properties of the composite steel sheet pile members in each test stage is studied as well.