Experiments And Numerical Simulation On Bending Stiffness Of U-shaped Steel Sheet Pile Wall

Steel sheet pile is a kind of Hot rolled(cold-formed)steel with both sides have interlock,and through edge interlocks to form a continuous vertical sheet pile wall to support water or soil.As a new type of flexible supporting structure,steel sheet pile has been widely used in foundation pit,cofferdam,levee anti seepage and disaster relief with the advantages of high construction efficiency,strong durability,good adaptability and less land occupation.Due to the particularity of steel sheet pile structure and the complexity of lock connection friction,it is difficult to study the mechanical properties of steel sheet pile.The friction characteristics directly affect the shear transfer state between the locking ports,thus affecting the mechanical properties of pile wal s.For this reason,a series of problems caused by different loading modes and interlock friction coefficient of steel sheet piles are studied based on field prototype test and finite element numerical simulation:1.Friction tests were carried out on several commonly used lock mouth friction conditions,such as interlock grease,interlock mouth not processing,interlock sand filling and interlock corrosion,and the friction coefficient of the interlocks was measured and applied to numerical simulation analysis.2.U-shaped steel sheet pile experiment were carried out based on bending characteristics,focusing on analysis of characteristics of steel sheet pile wall cross-section strain distribution,trend of change of sheet pile wall interlock strain,characteristics of relative slippage of the interlocks and the variation law of neutral axis.It is found that with the increase of bending deformation,the bending stiffness of steel sheet pile wal s always keeps a steady trend,and tends to be closer to the bending stiffness of single piles3.The ABAQUS finite element software is used to establish the calculation model consistent with the field test,and the rationality of the finite element analysis method is verified by comparing with the field test results.Working on different factors(load patterns / friction coefficients/ support span)to study the mechanical characteristics of steel sheet pile.Focusing on the distribution law of neutral axis,the characteristics of curvature and bending stiffness along the long direction of the pile,and studying the relationships between crosssectional neutral axis and interlock contact surface friction,bending stiffness of steel sheet pile.It is found that the bending stiffness of the steel sheet pile wall at the support of the pile wall is more obvious than that other sections.At the same time,the development of the bending stiffness of the pile wall depends on the total force ratio of the lock's friction force,and the forming mechanism of the bending stiffness of steel sheet pile walls is further analyzed.