Term of Award

Spring 2024

Degree Name

Master of Science, Civil Engineering

Document Type and Release Option

Thesis (open access)

Copyright Statement / License for Reuse

Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 License.

Department

Department of Civil Engineering and Construction

Committee Chair

Soonkie Nam

Committee Member 1

Gustavo Maldonado

Committee Member 2

Xiaoming Yang

Abstract

The purpose of the field verification of piles is to check whether piles can withstand design load. Two commonly used methods are high strain dynamic piles and static load testing. Static load testing is very time-consuming, requires heavy deadloads and much space, and doesn’t have stress monitoring advantages in piles. High strain dynamic has been employed as an alternative in this regard. Pile dynamic analyzer (PDA) is a device which is used during dynamic testing to analyze the measurements from the test. PDA calculates the geotechnical or structural resistance by using wave mechanics algorithm installed in it. Total driving resistance (or geotechnical resistance) consists of dynamic and static resistance. In PDA, the pile capacity is considered as static resistance which is calculated using Case formula. In this formula, a Case damping factor which represents ground condition needs to be selected carefully since it affects the estimation of maximum pile capacity (RMX). It was found that 0.9 of Case damping factor was used in the reviewed projects with PDA. This is believed to be irrelevant to the ground conditions. Therefore, the estimated ultimate pile capacity (RMX) could be questionable. However, this issue is not supposed to be critical as the final estimation of the pile capacity is estimated by the result of CAPWAP analysis. It has not been confirmed whether the Case damping factor estimated by CAPWAP represents the ground conditions well, especially for rock. Hence, the Case damping factor from CAPWAP still needs to be verified, preferably by static load test. However, it is expected to be very uneconomical for rock, thus alternative methods are recommended for investigation. The CAPWAP damping factors grouped by Banks and Cobb Counties show a good trend against blows per inch in each group. However, it still needs to be interpreted carefully as the other factors affect the penetration of a pile.

Research Data and Supplementary Material

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