Analysis Of Mechanical Characteristics Of Rigid Pile Composite Foundation Under Cyclic Loading

As a widely used and economical foundation treatment technology,rigid pile composite foundation has been widely concerned by many researchers.In recent years,the research on rigid pile composite foundation has focused on static load,but in actual engineering,The dynamic loading of rigid pile composite foundation can not be ignored.Therefore,it is of great significance to study the mechanical behavior of rigid pile composite foundation under cyclic loading.In this paper,the subgrade treated by rigid pile composite foundation is taken as the research object.The cycle number,the characteristics of the cushion layer,the soil modulus of the reinforcement zone and the bearing layer,the pile spacing of the rigid pile and the pile length are analyzed by numerical simulation.The dynamic characteristics of rigid pile composite foundation under load are obtained.The variation of pile axial force,pile side friction resistance,neutral depth and pile-soil stress ratio of rigid pile composite foundation under different factors are obtained.In order to study the settlement characteristics of rigid piles under composite cyclic loading,the numerical simulation and empirical formula are combined to study the variation of different influencing factors on the settlement of composite foundation under low cycle and high cycle loading.On the basis of the settlement of composite foundation under cyclic loading,based on the analytic hierarchy process,the layer structure of composite foundation settlement under cyclic loading is constructed by using the cushion layer characteristics,soil characteristics and rigid pile characteristics as the criterion layer.The weights of the composite foundations under the low-cycle and high-cycle cyclic loading are analyzed.The weights of the various factors affecting the settlement of the composite foundation under the low-cycle cyclic loading are as follows: pile spacing,holding The modulus of the soil layer,the length of the pile,the thickness of the cushion layer,the modulus of the soil in the reinforcement zone,and the modulus of the cushion layer;the importance of each factor under the high cycle load is from the largest to the smallest: pile length,holding The modulus of the soil layer,the spacing of the piles,the thickness of the cushion layer,the modulus of the soil in the reinforcement zone,and the modulus of the cushion layer.According to the influencing factors,the weighting of the settlement of composite foundation under cyclic loading will provide some guidance for the design of actual engineering.