Research Of Dynamic Simulation Technique On Casing Pipes Construction Of Deep-water Elevated Pile Foundation Work

In recent years, there are more and more bridges that span great rivers are built along with continual development of national economy. Deep-water pile foundation is applied for great span bridges at large. Most of the deep-water pile foundations in bridge construction are pile group. People used the steel casing pipes and the steel pipe piles to establish the work zone during the process of foundation construction. The technics of the pile driving is applied at large,unfortunately,the studies on the pile driving process are unwonted. So people pay more and more attention to the economical and secure structural style of the steel casing pipes and the steel pipe piles with appropriate impact load, especially for the unredeemable steel casing pipes.This paper mainly studied for the sinkage and stress of the steel casing pipes in the impact situation, and the influence of casing pipes thickness and the impact force. In this paper, some major research directions in the stability theory of structure were introduced, as well as the progress of research in dynamic stability field.The advances in the research of dynamic elastic buckling of cylindrical thin shells under axial impact loading are reviewed comprehensively.The main comments are systematically remark on the dynamic buckling modes, dynamic buckling criterion for the structure subjected to impact loading.Meanwhile, The geometrical equations ,equilibrium relations, constitutional relationship,and the equations of the elastic cylindrical thin shell motion on the nonlinear buckling problem were introduced. In addition, the basal theory of the stress wave and the arithmetic of the ANSYS/LS-DYNA software were introduced. Combined with Liushuihe bridge construction, we've simulated the processes that steel casing pipes driven into the soil with impact loads by using the software of the ANSYS/LS-DYNA, and studied sinkage and stress of the steel casing pipes in the process of driving into the soil, experimented in the construction field. The simulation results are agreed with the experiments well. Based on the work above, studied the influence of casing pipes thickness and the impact force to the sinkage and stress. The result, in this paper, provides referrence for the impact rammer choosing, structural style of the casing pipes, safety method, and economical design.