Centrifuge Tests And Numeric Analysis On The Bearing Capacity Of Single Pile

Pile foundation is a traditional type of deep foundation. The bearing capacity of single pile is affected by the pile forming method, loading type and the status of surrounding soil. To investigate the influence of these factors, this paper conducts a series of centrifuge tests in the drum geo-centrifuge lab in DUT. The soil used in the centrifuge tests is Fujian standard sand which is screened by 0.5 mm size screen. To avoid the influence of people during the process of preparing the sand sample, the auto sand sample preparation instrument is used in this paper. So the sand sample has well uniformity and repeatability. The tests results show that the friction factor of pile surface affects the pile bearing capacity directly. The result of test, in which three gauges are adhere on the surface of pile model, is much bigger than the results of other tests. It is true that the change of pile surface caused by the gauges have huge effect of the bearing capacity of pile, which becomes bigger. Secondly, by comparing the results of embedded pile and driven pile, the loading of driven pile is bigger than the other one. The reason is that the soil around the pile model becomes denser during the driven process. Thirdly, the greater relative density leads to higher bearing capacity of pile. Fourthly, the distribution of axial force on the pile model is measured by adhering gauge on three different places. The friction force on the pile is mostly focusing in the down 1/3 pile embedded part, because the soil pressure is bigger there. But the distribution of friction on the pile surface cannot be described by linear shape.The large finite element software ABAQUS is used to do some relative numeric analysis. In this paper, the axisymmetric model,3D model and the CEL method is applied to simulate the single pile behavior under vertical loading, horizontal loading and the penetration process of single pile, respectively. Through the comparison of the numeric results and model tests results, the effectiveness of numeric analysis is verified. Combining model test and numeric analysis can provide reference for engineering design.