Date of Award

Spring 2001

Document Type

Thesis

Degree Name

Degree of Engineer in Civil Engineering

Department

Civil and Environmental Engineering

First Advisor

Dorairaja Raghu

Second Advisor

John R. Schuring

Third Advisor

Edward G. Dauenheimer

Abstract

A study of the effects of time on axial pile capacity in glacial deposits is presented in this report. The dynamic and static load database test results of the Route 21, Viaduct Replacement project are studied and analyzed. In this project two sizes (18-inch and 24-inch dia.) of closed end pipe piles varying in length 100 to 150 feet driven through highly variable glacial deposits were utilized. Within a small reach the subsurface conditions and the behavior of pile capacity with time varied considerably. About 112 piles were tested dynamically by Pile Driving Analyzer. Restriking was performed on fifty-nine piles to establish the soil setup behavior. Restriking was performed generally at two and four weeks after the initial driving. Project area is divided into four soil types to characterize the soil setup behavior. With the exception of one soil type, the pile capacity increased with time. Most of the pile capacity increased within two weeks after driving and after that a moderate increase was observed. Capacity versus time relationship has been evaluated for each soil type and a reasonable setup behavior equation to predict the long term capacity in similar soils has been developed. With one exception, the capacity evaluated by static load tests were about 25 percent higher than the dynamic load tests. The use of dynamic tests to quantify the soil setup behavior in a glacial deposit is realized. The research is substantiated by relevant literature review. Conclusions are drawn and further research is recommended.

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