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Title:

STRUCTURAL BEHAVIOR OF 45-DEGREE UNDERREAMED FOOTINGS

Accession Number:

00468620

Record Type:

Component

Availability:

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Order URL: http://worldcat.org/isbn/0309044723

Abstract:

In this paper is described an experimental and analytical study aimed at developing a better understanding of the structural behavior of 45-degree underreamed footings. Two instrumented 45-degree footings 7.5 ft (2.29 m) in diameter with shafts 2.5 ft (0.76 m) in diameter were load tested under differing geotechnical conditions. One footing was situated in a very stiff clay, and the other was placed on a stratum of clay shale. In both tests failure occurred because of either bearing capacity failure of the footing itself or pullout failure of an anchor shaft. The footings sustained mean net bearing pressures of 100 psi (clay) and 157 psi (clay shale) without developing observable structural distress. Finite element analyses predicted well the measured base pressure distribution and the load-settlement characteristics of the footings; however, the maximum predicted tensile stresses in the underream under the imposed loads exceeded the tensile strength of concrete beam specimens tested to failure in flexure. Because no tensile cracking was actually observed in the test footings, a more realistic tensile strength criterion that relates to the status of stress in the footing needs to be established.

Supplemental Notes:

Publication of this paper sponsored by Committee on Foundations of Bridges and Other Structures. Distribution, posting, or copying of this PDF is strictly prohibited without written permission of the Transportation Research Board of the National Academy of Sciences. Unless otherwise indicated, all materials in this PDF are copyrighted by the National Academy of Sciences. Copyright © National Academy of Sciences. All rights reserved

Monograph Title:

Geotechnology

Monograph Accession #:

01418086

Authors:

Sheikh, Shamim A
O'Neill, Michael W

Pagination:

pp 83-90

Publication Date:

1987

Serial:

Transportation Research Record

Issue Number: 1119
Publisher: Transportation Research Board
ISSN: 0361-1981

ISBN:

0309044723

Media Type:

Print

Features:

Figures (10) ; Photos (4) ; References (10) ; Tables (1)

Old TRIS Terms:

Subject Areas:

Bridges and other structures; Design; Geotechnology; Highways; I24: Design of Bridges and Retaining Walls; I42: Soil Mechanics

Files:

TRIS, TRB, ATRI

Created Date:

May 31 1988 12:00AM

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