Study On Buckling Instability Of Individual Pile Under Liquefiable Sandy Soil

With the development of modern society,the application of pile foundation in all aspects of the structure is increasing.In modern engineering many slender individual piles are used to support the superstructure,such as tall buildings,bridges,ports,etc..When there is an earthquake,the individual pile with potential seismic liquefaction area may face the risk of buckling instability.When the earthquake induced liquefaction of soil,the soil around the pile loses effective restraint stress,which can not provide effective support for the pile.It is of great significance for improving the safety of the structure to study the buckling instability of the individual pile under the liquefiable sandy soil.In this paper,the buckling instability of individual pile under liquefiable sand is studied by means of finite element software ABAQUS combined with a centrifugal test.The study consists of two parts:First,the critical load of the piles is determined,and the effect of the liquefaction on the piles is considered.By analyzing the theoretical framework of sand,the basic principle of sand liquefaction and judging,the parameters of sand before and after liquefaction are obtained,and stablish the soil stress.By studying the theoretical solution of individual pile buckling and the example of centrifugal test,the results of buckling test of individual pile are compared with numerical simulation results.And in numerical simulation,the effect of liquefied sand on the flexion of individual pile is considered.The second is to consider under different conditions,respectively,the impact of pile buckling.On the basis of determining the ground stress,the influence of the boundary condition,the length of the pile and the shell thickness is obtained.In order to analyze the relevant conclusions of the nonlinear buckling of the individual pile,the initial defects are added to the pile body,and the load displacement curve of the model pile and the pile stress curve are obtained.