Undergraduate student, Humboldt State University, Arcata, CA
Professor and director, Humboldt State University Marine Laboratory, Trinidad, CA
Pages: 15 Published: Jan 1988
Gas types, zonation present in marine sediments, the corresponding mechanism of bubble formation, and methods of performing traxial tests on gassy sediments are discussed. Gases (methane and hydrogen sulfide; methane gas predominates) may be found either in solution or in the bubble phase in the sediment. A method to estimate the amount of gas that theoretically comes out of solution is shown. The result of gas bubbles is a reduction in the bulk modulus of the pore fluid. The bulk modulus of a gas-water mixture decreases with incresing fluid pressure. Results of decreasing bulk modulus are shown to reduce the pore pressure increment per application of a load increment. Triaxial testing techniques are recommended when (1) gas is in solution, (2) gas is in the bubble phase, and (3) gas is still evolving.
gas, pore pressure, marine, sediments, triaxial
Paper ID: STP29085S