Date of Award

2007

Publication Type

Doctoral Thesis

Degree Name

Ph.D.

Department

Civil and Environmental Engineering

Keywords

Applied sciences, Cyclic loading, Laterally loaded piles, Nonhomogeneous soils, Sand, Soft clay, Soil

Supervisor

Barbara Budkowska

Rights

info:eu-repo/semantics/openAccess

Abstract

Laterally loaded piles are widely used to support many structures such as high-rise buildings, bridge abutments and offshore structures. This dissertation presents the study of the sensitivity of laterally loaded piles embedded in non-homogeneous soil consisting of soft clay overlying sand subjected to cyclic loading. The study is divided into three parts.

In the first part, the theoretical formulation for the sensitivity of the pile's head lateral deflection and rotation to changes in the design parameters was derived for single and group piles. The distributed parameter sensitivity approach was used in the derivation with three different formulation techniques of the adjoint method. The design parameters considered were those defining the pile and the adjacent clay and sand. Five forms of sensitivity results were obtained.

In the second part, various numerical sensitivity investigations were conducted including single piles and pile groups. Different pile lengths, pile head boundary conditions, and pile loadings were studied. In addition, the effect of pile spacing and pile location for a pile group, and the thickness of the overlying clay were investigated. More than 700 different cases for single and pile groups were studied using developed MATLAB programs, COM246P for single piles and FB-Pier for pile groups. The obtained results were verified by conducting an error analysis assessment.

In the third part of this research, a user-friendly sensitivity program for laterally loaded piles was developed which allows the engineer to input his own data. The program is based on the theoretical formulation and is developed using MATLAB. It offers the numerical and graphical presentation of the five forms of sensitivity results.

The results presented in this study enhance the understanding of the behavior of the laterally loaded pile-soil system. In addition, they allow the engineer to detect the critical locations of influence of each parameter along the pile length and quantitatively assess and compare that influence. Furthermore, an engineering tool for sensitivity is provided. Accordingly, the proposed research has considerable practical application in improving the design of the pile systems, solving infrastructure aging problems, monitoring processes, and helping in rehabilitation and renovation activities.

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