Report No.: CCEER-91-2

Authors: G. Norris, R. Siddharthan, Z. Zafir, S. Abdel-Ghaffar, and P. Gowda

Date: July 1991

Sponsoring Agency: California Department of Conservation, Division of Mines and Geology

Performing Organization:

Department of Civil Engineering/258

University of Nevada, Reno

Reno, NV 89557

Abstract:

This paper discusses the use of CSMIP records at Oakland Outer Harbor Wharf (along with records from Yerba Buena and Treasure Island) to study the free-field motions at Oakland Outer Harbor, both at shallow depth and to bedrock, and the possible softening of soils surrounding the piles supporting the instrumented wharf. The paper also discusses the determination of the motion on the instrumented wharf using free-field motion input and deflection compatible lateral and vertical pile foundation stiffnesses. Such derived motion compares well with the recorded motions on the deck. While there was no reported liquefaction at the site, there was at nearby locations; and the consequence of an assumed lower relative density of the near-surface sand at Oakland Outer Harbor is discussed. Likewise, the consequence of a change in the orientation of the wharf or the incoming motions, assessed by interchanging the direction of the free-field motions, is presented. These latter changes reflect conditions under which a soil-foundation interaction failure or structural failure of the batter piles may have developed, failures that occurred at facilities nearby (Abstract by authors).