Simulation Centrifuge Test On Bearing Features Of Loess Foundation Bridge Group Under Inhomogeneous Collapsibility Condition

Inhomegeneous collapsibility of the loess district has great effect on a series of projectssuch as bridge pile. So how to determine the pile bearing capacity and pile lateral negativefriction resistance in this loess is the urgent and key problems that need to solve on bridge piledesign. This paper, based on the bridge pile foundation project under inhomogeneouscollapsibility condition in Shanxi River transport and High speed loess district, usingsimulation centrifuge test and numerical simulation, have done a systematic study on theloading features of loess group pile foundation under, inhomogeneous collapsibility and loessfoundation bridge pile group based on complicated geographical conditions.In the simulation centrifuge test, it adopts enforcing load in soil Method to themethod to simulate the loess inhomogeneous collapsibility that generated by soaking the loessinto water. It mainly do the single pile and group pile simulation test of loess underinhomogeneous collapsibility condition; it studies a series bearing features such as pile topsedimentation、pile axial force and pile lateral friction; It discusses the effect of even anduneven transformation to the pile group negative friction resistance; it further analyzes howdifferent terrains affect the negative friction resistance.Finally, using the finite element software, based on the mechanism of loess collapsibility,it puts forward the water equivalent principle to simulate the loess inhomegeneouscollapsibility, and it does the numerical simulation of the stress feature of pile group based onthe Shanxi River transport and High speed bridge pile group project to analyze the changingrules of the pile group lateral friction resistance when pile group is under the vertical load.