Analysis of Ocean Bottom Sediments

Abstract

The Civil Engineering Dept. of the University of British Columbia was requested by Lockheed Offshore Petroleum Services Ltd. to perform laboratory tests on ocean bottom sediments taken from a depth of 1,200 ft in the Strait of Georgia, British Columbia. The main purpose of the tests was to determine the stability and settlement of a pedestal base to be placed on the ocean bottom. A secondary purpose was to estimate the force required to lift the pedestal base from the seabed. Samples of the ocean bottom sediments were obtained by dropping a 12-ft long x 2-3/8-in. diam gravity core sampler into the sediments. The sampler was weighted and was allowed to hit the bottom at considerable speed such that the whole sampler penetrated the sediments. During the first 2 sampling attempts, the core catcher placed at the bottom of the sampling tube seemed to prevent the soft material from entering the tube and only a small amount of material was recovered in the sampling shoe.