Location

Chicago, Illinois

Session Start Date

4-29-2013

Session End Date

5-15-2013

Abstract

A load testing program was undertaken to determine the working capacity of drilled shafts in Simsima Limestone, the predominant founding stratum in Doha, Qatar. The drilled shafts ranged from 500 mm to 1,500 mm in diameter and gained capacity from both side and base resistance within the Simsima Limestone. The weathering profile of the Simsima Limestone is complex with the degree of weathering likely to increase or decrease with depth. For the purposes of design, the limestone was characterized into three grades of weathering (A, B, and C) and the pile load testing program focused on testing each of these zones. The load testing program consisted of a series of instrumented Osterberg-cell tests, conventional jack and reaction-frame tests, highstrain dynamic tests, and tension tests to determine the pile-rock interactions within the various zones of Simsima Limestone. The load test results are presented and the findings summarized. Construction of the working piles raised concerns about the effect of softening with time for the exposed limestone during drilling. Extrapolation of the results of the load testing program and additional high-strain dynamic testing were used to address these issues. The results of the tests are presented and compared to the design assumptions with suggestions made to optimize future designs.

Department(s)

Civil, Architectural and Environmental Engineering

Appears In

International Conference on Case Histories in Geotechnical Engineering

Meeting Name

Seventh Conference

Publisher

Missouri University of Science and Technology

Publication Date

4-29-2013

Document Version

Final Version

Rights

© 2013 Missouri University of Science and Technology, All rights reserved.

Document Type

Article - Conference proceedings

File Type

text

Language

English

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Apr 29th, 12:00 AM May 15th, 12:00 AM

Preliminary and Working Pile Load Tests in Simsima Limestone

Chicago, Illinois

A load testing program was undertaken to determine the working capacity of drilled shafts in Simsima Limestone, the predominant founding stratum in Doha, Qatar. The drilled shafts ranged from 500 mm to 1,500 mm in diameter and gained capacity from both side and base resistance within the Simsima Limestone. The weathering profile of the Simsima Limestone is complex with the degree of weathering likely to increase or decrease with depth. For the purposes of design, the limestone was characterized into three grades of weathering (A, B, and C) and the pile load testing program focused on testing each of these zones. The load testing program consisted of a series of instrumented Osterberg-cell tests, conventional jack and reaction-frame tests, highstrain dynamic tests, and tension tests to determine the pile-rock interactions within the various zones of Simsima Limestone. The load test results are presented and the findings summarized. Construction of the working piles raised concerns about the effect of softening with time for the exposed limestone during drilling. Extrapolation of the results of the load testing program and additional high-strain dynamic testing were used to address these issues. The results of the tests are presented and compared to the design assumptions with suggestions made to optimize future designs.