Study On Mechanical Test And Numerical Simulation Of HUI Composite Steel Sheet Pile

Under the background of the "14th five-year Plan" building energy saving and green building development planning,HUI composite steel sheet pile,as a new type of foundation pit protection system,has the advantages of convenient construction,superior water sealing performance,less environmental pollution,recyclability and large bending stiffness of H-shaped steel,which meets the requirements of building energy saving and green building.At the same time,the two-way interlock of H-shaped steel flange makes the connection between H-shaped steel and U-shaped steel sheet pile more convenient and diverse,and further enriches the combination type and application range of composite steel sheet pile.In this paper,the mechanical properties and insertion ratio of HUI composite steel sheet pile are studied systematically through theoretical analysis,laboratory test and numerical simulation.The main research contents and results are as follows:(1)Based on the basic principle of material mechanics,the calculation methods of cross-section mechanical parameters of HUI composite steel sheet piles are summarized,and compared with the calculation methods of ABAQUS finite element simulation,it is concluded that the errors of inertia moment and bending stiffness calculated by the two methods are in the range of 2.42%-11.53%.Finally,by comparing the cross-section mechanical parameters of the five main combinations of HUI composite steel sheet piles,the proposed combination types are given.(2)The tensile test of HUI composite steel sheet pile interlock is carried out,and the interlock tensile performance of steel sheet pile is studied.The test results show that the ultimate tensile bearing capacity of steel sheet pile is 83.2 k N.(3)The bending performance test of HUI composite steel sheet pile is carried out,and the bending performance of steel sheet pile is studied.Based on the analysis of the test results,it is concluded that the bending specimen of steel sheet pile imposes intermittent weld by interlock,which makes the neutral axis move,the maximum bending bearing capacity is increased by about 100 k N,and the bending performance is improved obviously.(4)Based on the deflection measurement results of the bending performance test,through the incremental method,it is calculated that the bending stiffness of each section of bending specimen 1 and bending specimen 2 is similar,and the reduction coefficient of bending stiffness of steel sheet pile in practical application is between 0.55 and 0.65.(5)Based on a project in Shaoxing,the numerical simulation of HUI composite steel sheet pile support is carried out,and the insertion ratio of HUI composite steel sheet pile in practical engineering is studied.It is suggested that the insertion ratio of HUI composite steel sheet pile should be 1.0 to 1.2.In order to ensure the safety reserve,the insertion ratio can also be increased appropriately.The depth of foundation pit excavation,the bending stiffness of steel sheet pile retaining wall and the working condition of dangerous soil layer have no obvious influence on the insertion ratio of steel sheet pile retaining wall.