English abstract
Abstract
The objective of this study is to understand potential scour effects on the behavior of laterally loaded piles by considering the most effective factors. Two methods were adopted to analyze the pile-soil interaction: laboratory model tests and the finite element method of analysis. The experimental program was divided in two main parts, single pile and a group of piles (nine piles). The influence of different factors such as: the scour depth, the presence of vertical load, pile configurations and the effect of riprap, were studied. In both methods the study was performed for both single pile and a group of piles. The scour depth was varied from 10 to 3D (where D is pile diameter). The size of test tank wa designed large enough to minimize the influence of the box boundaries. However, they were two different type of sands were used in this study. A preinstalled method was used to install the model pile and the tests were adopted in one L/D ratio (where L is pile length). A finite element program (ABAQUS) was used to study the effect of the scour on the single pile. In the numerical model, the pile was treated as a linear elastic material and the soil was idealized using the Mohr-Coulomb constitutive model. Moreover, a comparisons between the results of the laboratory model tests and the finite element analysis were made. A substantial reduction in ultimate lateral capacity for a single pile and pile group due to scour is observed. The percentage decrease of the lateral load capacity (PDC) reaches almost 45% and 38 % when the scour depth increases from 0 to 3 D, for a single pile and pile group, respectively. The presence of the vertical load and the riprap increases the lateral load resistance. The influence of vertical load on the lateral response of a group of piles is significant, however, the influence is less in the case of single group, the overlapping of stresses of adjacent piles affect its ultimate lateral resistance. Thus, the leading row of piles attract higher load level than the middle and back row piles.
