Papers by Keyword: Single Pile

Abstract: Piles are generally required to transfer load from a superstructure through weak or compressible strata, or through water, on to stiffer and less compressible soils and rock. The pile behavior is very important in Soil-Pile interaction (as known Kinematic Interaction) so that grouped and single pile behavior differs owing to the impacts of the pile-to-pile interaction. In this research presents a series of experimental investigations carried out on single and group pile subjected to monotonic lateral loadings. The aluminum model piles were tested in the different relative densities in Johor Bahru sand. The sand samples were prepared by using the newly designed Mobile Pluviator adopted the air pluviation method. The different configurations of model pile groups for embedded length-to-diameter ratio equal to 32 into loose and dense sand spacing from 3 to 6 pile diameter (D) were conducted. The ultimate lateral load is increased 53% in increasing of s/d from 3 to 6 owing to effects of sand relative density. A ratio of s/D more than 6d is large enough to eliminate the pile-to-pile interaction and the group effects. It may be more in the loose sand.

Abstract: This paper explains load tests of models of bored concrete piles. In 2014 an experiment was carried out using testing equipment. The testing equipment was constructed at the Faculty of Civil Engineering, VSB – Technical University of Ostrava. The purpose of the experiment was to test the feasibility and load carrying capacity of bored concrete pile models. During the experiment two models of floating bored concrete piles were loaded. The heel of the first pilot was adjusted, in order to verify only surface friction. The second pile was used to verify side and base resistance. The results of these load tests will be further used for the preparation of calculations and experiments on mixed pile foundations.

Abstract: Understanding the pile behavior and predicting the capacity of piles under horizontal load are important topics in foundation design. In this paper, the mechanical characteristics of single pile under horizontal load is analyzed based on FLAC3D finite difference software, and the load-displacement curve, the bending moment, shear force, soil resistance under all levels of load and the distribution law of p-y curve along the pile shaft are obtained. accordingly the following conclusions can be made: the bending moment of the upper part of pile body is big, the maximum bending moment is at the height of 2~3 meters and it is almost zero below the depth of 9 meters. The bending moment increases with the increase of load, the point of maximum bending moment moves down along the pile body with the increasing of horizontal load. and the location of the point of maximum bending moment moves from 2 meters below the ground to 3 meters below it. The distribution of soil resistance along the pile shaft is a reverse "S", the maximum of pile lateral soil resistance is at the height of about 2~3 meters below the ground.

Abstract: According to optimized fitting analysis for measured data in static load test of 22 different types of single piles, a new modified exponential model was proposed by authors in this paper. In comparison between the hyperbolic model and the integrated exponential curve model, the correlativity coefficients R of the modified exponential model were over 0.996. The fitting effect of the model of proposed in this paper is better than that of other models above-mentioned. The deviations between fitting and measured data in static load test for single pile was small, especially, in the tail pasts of fitting curves, the mean deviations of 2 test pile given in the paper are 1.61% and 1.99% respectively. The modified exponential model can be better described Q-S curves of single piles. It can be used to better evaluate the ultimate bearing capacity of single piles.

Abstract: In the paper, according to the definition of the effective length and criterion of the effective length of the single pile, using the numerical method to simulate the foundation of drilling hole perfusion of single pile under vertical load pile settlement and deformation of pile body, based on the way of combining the ultimate bearing capacity and settlement control of pile top, the pile efficiency coefficient of the effective pile length is determined in certain conditions, and also the effective length of single pile. Then, the more reasonable theoretical basis is provided for engineering design and construction.

Abstract: This article aims to study the influence of negative skin friction resistance of waterishlogged pile foundation, through indoor scale model test of pile foundation in the loess areas. The program involved in the model similar than design, the model groove design, the selection of test materials, the design of the ground soil, the layout of measuring points and the research of load method in the test. Through the experimental study on the reduced scale model, we can deepen the understanding of the action mechanism of negative skin friction resistance of the pile, which could guide the engineering practice and design.

Abstract: In this article, the distribution of plastic hinge model is adopted to simulate the elastic and plastic of pile body, p-y curve is used to simulate resistance of pile foundation soil. We do static non-linear pushover analysis of the single pile of pile foundations, and research the influence of the axial compressive ratio η of pile shaft, longitudinal reinforcement rate ρ of section, stirrup ratio µof section and shear strength C of foundation soil to the system-interaction of pile and soil. The result shows that axial compressive ratio of pile shaft has a significant influence on horizontal limit bearing capacity and the displacement ductility of the system. With the increase of the axial compressive ratio, system of the displacement ductility reduces gradually, but the limit bearing capacity increases gradually. Under a horizontal load, the order and the mechanism of plastic hinge are obviously different because of different axial compressive ratio of pile shaft，This analysis method may further provide a reference for nonlinear seismic analysis of pile bents.

Abstract: The construct to precast pile in thick clayey soil can cause the accumulation of excess pore water pressure. The high excess pore pressure can make soil, buildings and pipes surrounded have large deflection, even make them injured. Combining with actual projects, this paper presents an in-situ model test on the changes of excess pore water pressure caused by precast pile construct. It is found that the radius of influence range for single pile driven is about 15m，the excess pore water pressure can reach or even exceed the above effective soil pressure, and there are two relatively stable stages.

Abstract: Indoor model experiments were made to study loads on single pile under the wave-current flow. Take three different velocities of the current and three different diameters of piles in the experiments to get the variations of loads. Drag and lift forces were measured by a two-component balance. Analysis on experiment results shows that, both drag force and lift force increase with the increase of the pile diameter and the current velocity. The drag coefficient Cd increases with the increase of Kc number until Kc researches 12, when Kc is more than 12, Cd decreases with the increase of Kc; while the inertia force coefficient Cm decreases with the increase of Kc, when Kc is more than 12, C_m changes little. And the lift coefficient shows no correlation with the Kc number.

Abstract: The ABAQUS finite element software is used to calculate the vertical bearing capacity of single piles in Tianjin, and the finite element results are compared with the data gained through the in-situ static load pile foundation tests. It is found that the Young’s modulus of the soil at the bottom of the pile could have a important role in improving the vertical bearing capacity of single piles.