Experimental Study On Uplift Pile Of Flexible Pile

Tension piles are widely used to resist the uplift load，but conventional uplift pile in bearingpile body is in a state of tension, cracking occurs when the strain reaches a certain degree. We geta new type of soft top bottom uplift pile which can solve tension cracking and penetratefoundation raft. According to the laboratory model experiments and the finite element, Thisarticle study the soft top bottom uplift pile bearing capacity and the deformation. We obtain thefollowing results:(1)Summarizes the existing working mechanism of the uplift pile, and analyzes the existingproblems of uplift pile, And on the basis of the existing theories, we deducted the analyticformula for calculating of ultimate bearing capacity and displacement of the constant sectionAnti-pull soft top bottom uplift pile,(2)To design small size model uplift piles model based on the model similarity theory.Carrying out three different uplift pile model experiments in dry sand respectively. We analyzedthe differences of soft top bottom uplift pile in ultimate bearing capacity and displacement.Conventional uplift pile in bearing pile body is in a state of tension and axial stress graduallydecreased along the pile top to bottom;soft top bottom uplift uplift pile in bearing pile body is in astate of compression and axial stress gradually decreased along the pile bottom to top.(3)According to bearing capacity of uplift piles using the theory of the public resistance topile drawing size of the actual stress and displacement of pile. Studying bearing capacity anddisplacement in finite element analysis and research, ensure the rationality of theexperiments.Summarizes the existing working mechanism of the uplift pile.(4)This paper analyzed the bearing characteristics of the anti-pull soft top bottom uplift pileand conventional uplift piles in the sandy soil by the finite element. We analyzed the reasons forthe differences of anti-pull soft top bottom uplift pile and conventional uplift pile bearingcharacteristics in the sand soil. Finally, we analyzed the influence of slenderness ratio and thePoisson’s ratio of pile and shear modulus and Poisson’s ratio of soil on the ultimate capacity ratioof anti-pull soft top bottom uplift pile and conventional uplift pile. And we gave the anti-pull softtop bottom uplift pile bearing capacity calculation formula.