00611720

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http://onlinepubs.trb.org...1991/1290vol1/1290-043.pdf

https://scholar.google.co...rius&publication_year=1991

The October 17, 1989 Loma Prieta earthquake provided an ideal time and situation to perform for the first time, at no installation cost, a full scale lateral load test on a group of driven piles in typical bridge footings at the Cypress Street Viaduct. Since these foundations were no longer going to be used, we were able to load them laterally to failure and record load versus deflection. Testing was performed at two different locations. Location #1 consisted of 60 ft long piles in a clayey (bay mud) material, and location #2 consisted of 15 ft long piles in sandy silt. Preliminary results were very encouraging. Lateral pile capacities were observed at 1/4 in. deflection, which greatly exceed the Bridge Design Specifications criteria. Reduced data produced a range from 17 kips to approximately 26 kips per pile in these two soil types. Considering that we use 5 kips/pile in today's design criteria for this type of pile, one can readily see that if this number were increased to just 10 kips, the number of piles required for lateral forces would be significantly reduced, thereby achieving an appreciable reduction in cost for foundations of this type. Pile capacities are correlated with appropriate soil parameters for the two soil types. Bridge Design Specifications are being proposed to take advantage of the increased lateral load capacities obtained in this research project.

This paper appears in Transportation Research Record No. 1290, Third Bridge Engineering Conference, March 10-13, 1991, Denver, Colorado, Volume 2. 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

01411114

p. 139-144

1991

Transportation Research Record

Bridge Engineering Conference, 3rd, 1991, Denver, Colorado, USA

0309050677

Figures (7) ; References (1) ; Tables (1)

Bridge design; Bridge foundations; Bridges; Clay; Deflection; Earthquake resistant design; Earthquake resistant structures; Highway bridges; Load tests; Sandy soils; Silts; Specifications; Structural design; Support piles

Loma Prieta Earthquake, October 17, 1989

Driven piles; Lateral loads; Sandy silts

Bridges and other structures; Design; Highways; I24: Design of Bridges and Retaining Walls

TRIS, TRB

Aug 31 1991 12:00AM