Date of Award

1994

Degree Type

Dissertation

Degree Name

Doctor of Philosophy

Abstract

The determination of stiffness and damping of piles is an important step in the analysis of pile-supported structures subjected to dynamic loading.;The first part of this study examines the use of approximate methods to evaluate the impedance functions of single piles and pile groups. The group impedances derived from the superposition of the two-pile solution are compared with those obtained from direct analysis. Good agreement is observed for floating piles in homogeneous and nonhomogeneous soil profiles. An extensive set of dynamic pile-soil-pile interaction factors is presented in a form suitable for interpolation. An approximate approach for the evaluation of pile-group impedances is proposed. The approach is based on combining the single-pile solution with curve-fitted expressions of the interaction factors.;In the second part of the study, field experiments are conducted to evaluate the response of a single pile and a pile group to harmonic loading. The experimental results are compared to the theoretical predictions of the linear theory. The comparisons indicate that the theory provides a good estimate of the single-pile and pile-group stiffness. However, the damping is significantly overestimated.;The third part of the study investigates the effects of separation and slippage at the pile-soil interface on the stiffness and damping parameters. A semi-analytical frequency-domain analysis and a time-domain boundary-element formulation are presented. Approximate corrections to the linear theory are suggested in order to include the effect of confining pressure and displacement amplitude on response predictions.

Share

COinS
 
 

To view the content in your browser, please download Adobe Reader or, alternately,
you may Download the file to your hard drive.

NOTE: The latest versions of Adobe Reader do not support viewing PDF files within Firefox on Mac OS and if you are using a modern (Intel) Mac, there is no official plugin for viewing PDF files within the browser window.