摘要:

Geotechnical characteristics of the sediments from a known submarine slope failure at Kitimat Arm, British Columbia, are related to the results of geological and geophysical surveys. Site geology and morphology of the fjord, evaluated from high‐resolution side‐scan sonar and subbottom profile data, show the effects of at least three separate instability events. The geotechnical properties of the sediments involved in the instability processes have been analyzed from piston cores and cores collected from a manned submersible. Four distinct instability mechanisms are identified within the fjord, including failure of the fjord wall and delta‐front sediments, initiation of movement of fjord‐bottom clays, long‐distance translational movement on the low‐angle fjord floor, and block gliding at the downslope front of the landslide. Using post‐failure geometries and geotechnical data, factors such as coastal construction, tidally induced drawdown, and undrained loading are evaluated as possible initiators of sediment instability.

ISSN:0360-8867    

DOI:10.1080/10641198609388190

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

An analysis of the relationship between organic matter and liquid and plastic limits, and grain‐specific gravity of a marine sediment was accomplished by making a stepwise adjustment in the organic content of that sediment. The sample used was from Santa Barbara Basin (off southern California) and is typical of fine‐grained marine sediments: it is a clayey silt with a common suite of minerals and other constituents. During the experiment, texture and composition (except organic content) were constant; only the quantity of natural, indigenous organic matter was changed.

ISSN:0360-8867    

DOI:10.1080/10641198609388191

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

The strength of saturated clays subjected to low‐frequency cyclic loading is of considerable importance in the design of offshore structures. A series of postcyclic undrained triaxial strength tests were carried out on samples of a silty clay (Keuper Marl), which had not failed under cyclic loading, to investigate the effect of this loading on the postcyclic monotonie effective stress path and strength of the soil. Undrained cyclic loading of normally consolidated and lightly overconsolidated samples by generating positive pore pressures caused the apparent degree of overconsolidation to increase. Samples subsequently subjected to monotonie testing followed effective stress paths commensurate with this apparent overconsolidation and failed on the “Hvorslev” surface on the “dry” side of the stable state boundary surface rather than on the critical state as would be expected of samples of this initial stress history. Samples which were initially heavily overconsolidated did not generate large pore pressures under cyclic loading and did not therefore exhibit large changes in postcyclic monotonie strength. The reduction in strength after cyclic loading therefore is greater for normally consolidated and lightly overconsolidated samples. The pore pressures generated under postcyclic monotonie loading are related to the degree of apparent overconsolidation achieved during cyclic loading.

ISSN:0360-8867    

DOI:10.1080/10641198609388192

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

Chemical, microbiological, and geophysical measurements have been carried out on sediment cores collected from Holyhead Harbour and the Western Irish Sea, where acoustic subbottom profiling has established the presence of large areas of acoustically turbid sediments, commonly referred to as “gassy” sediments. Gas analysis of these cores have shown that the acoustic turbidity was most probably due to high concentrations (>100 nM/mL) of methane occurring at subsurface depths.

ISSN:0360-8867    

DOI:10.1080/10641198609388193

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

Geotechnical Aspects of Coastal and Offshore Structures.Edited by Yudhair and A. S. Balasubramaniam. Proceedings of the Symposium on Geotechnical Aspects of Coastal and Offshore Structures, Bangkok, December 14–18,1981. Rotterdam: A. A. Balkema, 1983. 280 pp. $40.00.

ISSN:0360-8867    

DOI:10.1080/10641198609388194

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

ISSN:0360-8867    

DOI:10.1080/10641198609388195

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

ISSN:0360-8867    

DOI:10.1080/10641198609388189

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor