The Effect of Vertical Loads and the Pile Shape on Pile Group Response under Lateral Two-Way Cyclic Loading

Abstract

This paper is presented the lateral dynamic response of pile groups embedded in dry sand under influence of vertical loads and the pile shape in-group, which are subjected to the lateral two-way cyclic loads. The laboratory typical tests with pile groups (2×1) have an aluminum-pipe (i.e. circular, square) pile, embedded length to diameter of pile ratio (L/D=40) and spacing to diameter ratio (S/D) of 3, 5, 7 and 9 are used with different cyclic-load ratio (CLR) 0.4, 0.6 and 0.8. The experimental results are revealed that both the vertical and lateral pile capacity and displacement is significantly affected by the cyclic-loading factors i.e. (number of cycles, cyclic load ratio, and shape of pile) .In this study, important design references are presented. Which are explained that the response of the pile groups under cyclic lateral loading are clear affected by the attendance of vertical load and pile shape. Where, it is reduction the lateral displacement of group piles head and increase lateral capacity about (50) % compared without vertical loads. On the other side, the pile shape is a well affected to the pile response where the level of decline in lateral displacement at the pile groups head in the square pile is more than circular pile about 20 % at the same load intensity.

Effect of Spacing and Cross-Sectional Shape on Piled Raft System Subjected to Lateral Cyclic Loading

“…The results showed that an increase in the lateral resistance in the group of square piles compared to a circular pile under pure loading conditions within the group (1 × 2), (2 × 1) and (2 × 2) about (16%, 20% and 23%) respectively. Whereas this proportion increases by (30%) under combined loads for groups (1×2) and (2×1) and about (10%) for a group (2×2) These results agree with the study presented by [14], [15], [16] and [8].…”

“…In fact, piles are exposed to vertical and lateral loads at the same time, so it is important to distinguish the piles behavior in these situations [2]. Many researchers conducted analytical and experimental studies of piled raft foundations and studied the effect of several parameters on their behavior [3]and [4], whereas there are limited experimental studies are available that show the distribution of load within a pile group and studying the effect of spacing [5], [6]and [7] and cross-sectional shape [8] subjected to twoway cyclic lateral loading. However, the results of these studies show that the average load on a pile in a closely spaced group (three pile diameters or 3-D center-to-center distance) is much less than that of a single insulated pile with the same deflection, and the front (leading) row piles in the group carry significantly higher loads than the following row piles at the same deflection.…”

Estimation of The Maximum Bending Moment on Pile Group Under One-Way Cyclic Loading in Sandy Soil

“…This is due to the cyclic action reduced the soil reaction between the rows of piles. In other hand, the shadowing effect caused the leading piles to disrupt the soil between the rows this also recommended by (7) .…”

“…Such lateral cyclic loads on piles induced the reversal of stresses in the nearby soils, resulting in progressive degradation in strength and stiffness, which in turn caused a reduce in pile capacity with considerable irreversible deformation, resulting in failure in major situations. (6) Another study which is carried out by Mahmoud and Abbas (7) , states that the group piles were exposed to cyclic and vertical loading to illustrate the effect of the cyclically load ratio (CLR) on the behavior of piles. The findings showed that the lateral movement of the pile's head varied with the cyclically loaded ratio (CLR), before settling in a more consistent pattern, as the number of cycles increased.…”

The Behavior of Pile Group Under Inclined Static Load With Different Angle of Inclination in Sandy Soil

“…The ABAQUS finite element software is used to show the numerical simulation model to investigate the influence of horizontal component of inclined load on pile group and noticed Inclined load, embedded depth of pile cap, and eccentricity of the column are commonly influenced to improve the force of pile group [12]. Another researcher studied the influence of vertical loads on the pile group to lateral displacement [13].…”