A Three-Dimensional Nonlinear Numerical Simulation Of The Vertical Working Behavior Of Pile Foundations With Defective Piles

Pile foundation is important in all kinds of buildings and structures. Defect pilesare common in actual engineering. The usual defective forms are stem breakage, stemenlargement and bottom sediment. Because of the wide application of pile foundation,it is necessary to research the bearing behavior influenced by imperfection. Currentresearch on piles with imperfection is mainly focused on detection and remedialworks while research on bearing behavior of defective piles is rare. The bearingbehavior and working principle of both single piles and pile groups with imperfectionare analyzed by numerical methods.In this paper, single piles and four-pile groups with stem breakage, stemenlargement and bottom sediment are respectively simulated by a finite elementanalysis (FEA) program called FEAPPF-3D. The load-settlement curves of defectivepiles are obtained to compare with normal piles. Distribution Law of axial force andshaft resistance are obtained also. Then the effects of stem enlargement stem breakageand bottom sediment on pile foundation bearing capacity and the pile-soil interactionmechanism of defective piles are discussed.Research reveals the regulation of effect on vertical bearing capacity of pilefoundation by stem enlargement, bottom sediment and stem breakage. Researchresults have certain significance to engineering design and practice.