Research On The Lateral Bearing Properties Of Auger Cast-In-Place Piles

In engineering construction, piles are commonly used to support the axial load from upper buildings. Therefore, the understanding of the lateral bearing properties of piles is insufficient. Since laterally loaded pile is very important in the safety of buildings which resist laterally load, the research on it becomes meaningful and necessary.This paper has in-situ data from a pile testing project and compared the result with numerically simulated result with a finite element method. The good correlation between testing and FEM result testify the feasibility of numerical simulation in pile load testing. Based on this, this paper made further research on the influence of pile-soil parameter on behavior of laterally loaded piles with numerical simulation.In in-situ test, we get the data of axial force, moment, turning angle and deflection in different height and the lateral movement of pile in different loading level. It is obvious that the movement and deflection above 3m along the pile is a dominant factor in pile-soil resistance. Below this depth the movement and deflection decrease considerably and occurred a point of changing curve。It moves deeper slightly as the increase of lateral load, which shows deeper soil overtake the lateral resistance. The deflection and movement in the lower part of the pile is tiny enough to be neglected, as a pile fixed at the bottom area.The change of pile-soil parameters with a FEM simulation shows, for a certain lateral load and pile-soil parameters there is an appropriate pile length, which is enough to maintain safety and stability in engineering devised loads. It is economical since it has no extra useless length. Besides, as the increase of Elasticity modulus and pile size, the rigidity of soil 4 times around the radius of pile is increased to improve the side-resistance ability of foundation piles. The combination of in-situ experiment and FEM simulation, the proof of feasibility of FEM in simulating testing result, and the FEM research on pile behavior in different situation can greatly decrease the work of in-situ test, understand fully about the influence factors and regulation of pile loading behavior, and provide valuable suggestion in the design of foundation engineering.