Study On The Application Of Interfacial Mechanics Theory In The Interfacial Mechanical Behavior Of Pile Foundation

The pile-soil interface of a pile-soil system is the weakest part, mechanical problems of pile-soil interface are the most prominent ones in pile-soil interaction analysis. Neither in theoretical analysis or numerical analysis, research on the damage mechanism of long-pile-soil interface is very less. The distribution of cracks on pile-soil interface or shear stress on crack lines, and the relationship between cracks and settlement are undefined. There was no systemic theory research on this before. This paper fills the blank and the following works were done:(1) Based on the analysis of the interfacial characteristics between pile and porous medium soil, three basic assumptions are made, the non-contact parts are simplified to single cracks with limited width.(2) The fracture mechanics and interfacial mechanics are used to analyse the stress fields of the center cracks with limited width on interface of super-long pile indoor model test was done to verify the correctness of the expressions.(3)To establish numerical three-dimensional finite element model of long pile-soil system with vertical loads to simulate the settlement .(4) Under the assumption of theoretical derivation ,by using the birth and death functions in finite element software ,some contact pile-soil elements are killed to simulate interface crack, change contact stiffness, define parameters of the contact interface such as penetration area, and calculated settlement of super-long pile ,so as to fully reflect interaction mechanism of porous medium soil and pile.