Research About Stress And Deformation Of Tension Piles In Soft Ground

In this paper, based on the static-load tests of tension piles in soft ground lying on the province of Zhejiang such as Zhongshan Garden, Gongchen Bridge Canal Piazza,etc, the calculations of ascending displacement, developing mechanism of the side friction and utmost bearing capacity of the tension piles are studied.Failure modes of the tension piles are introduced first. Based on the failure modes, the utmost bearing capacity calculations of single uniform-section pile are analysed and studied. According to the engineering practise data , one method to calculating utmost single-pile bearing capacity is provided after simulating the uniform-section pile' Side friction curve by power-function math models. Analyseindicates that the method possesses good counting precision.The stress and deformation mechanism of expanding-bottom tension piles isanalysed. Then primary factors, which affect the utmost capacity and ascending displacement ,are offered and discussed.The Q-S curves which describe relations of load and displacement are simulated by power-function math models. And the method to forecast utmost bearing capacity of anchor-hold tension piles is offered. According to the static-load tests data, the differences of side frictions about the tension piles and the pression piles are contrastively analysed. The ratio between tension piles' side friction and pression piles' side friction is closed to 0.8.The primary factors, which affect the utmost capacity and ascending displacement ,are construed by using the FEM. And some suggestions about how to design tension piles are made.