Model Test And Theoretical Analysis Of Cable-stayed Under-Reamed Piles

Under-reamed piles were widely applied in foundation design of anti-float and anti-bending moment for structures. The engineering behavior of up-lift resistance under-reamed piles were comprehensively analyzed. And the work mechanism study for anti-horizontal under-reamed piles were not comprehensive. Present study for cable-stayed under-reamed piles is crude. In two respects of unplug and horizontal force,The current situation of study for under-reamed piles is summarized. Those calculation methods of displacement and bearing capacity of up-lift resistance under-reamed piles are overviewed. A formula of horizontal displacement of under-reamed piles bearing horizontal load is derived,a specific under-reamed pile of Aizhai bridge model test is designed,the accuracy of this formula is verified.Based on model test,The load-displacement curve of cable-stayed under-reamed piles is analyzed. Numerical simulate of the under-reamed pile applying FLAC3D finite difference software is done. And based on the outcomes,the engineering behavior of this cable-stayed under-reamed pile is analyzed. The comparison to straight pile is made.The research indicates: with the increase of cable-stayed load,the horizontal displacement and vertical displacement of under-reamed piles get increasing. The location at which the horizontal displacement of under-reamed pile is zero gets down in comparison to straight pile , The distribution of vertical displacement of under-reamed pile is uneven,the distribution of vertical stress of under-reamed pile is complicated.