摘要:

From a series of direct shear and laboratory vane shear tests conducted on natural pelagic and terrigenous marine soils, we have proposed a combined shear test procedure that involves obtaining the total stress failure envelope from tests on only two submarine soil samples. On one of the samples, both the direct shear and vane tests are conducted at zero normal stress. The second soil sample is consolidated under normal stressσngreater than the precompression stressPcand sheared in a direct shear device under normal stress equal to the above consolidation pressureσn, the laboratory vane shear test on the same sample is conducted under zero normal stress. The combined test program results in four datum points (two from direct shear and two from laboratory vane shear tests. By connecting the two vane test datum points, the cohesion line (the failure envelope corresponding to vane shear tests) is obtained. By connecting the direct shear test datum points (from the soil consolidated undercn> Pc) to the origin of thervs.σnplane, the part of the failure envelope that lies beyond the precompression load is determined. The part of the failure envelope curve below the precompression stress is obtained by drawing a line parallel to the cohesion line through the direct shear datum point (corresponding to zero normal stress). The data and procedure reported herein indicate that the investigator can realize considerable time savings as well as conservation of sometimes expensive and limited submarine soil samples by using the proposed combined test procedure.

ISSN:0360-8867    

DOI:10.1080/10641197809379791

出版商:Taylor & Francis Group    

年代:1978

数据来源: Taylor

摘要:

Cone resistance and laboratory strength measurements have been compared for stiff overconsolidated clays from five oil and gas fields in the North Sea. The clays considered are glacial in origin. The best agreement between cone resistance and laboratory strength is found by using anNkfactor equal to 17 in the formula

ISSN:0360-8867    

DOI:10.1080/10641197809379792

出版商:Taylor & Francis Group    

年代:1978

数据来源: Taylor

摘要:

Side‐scan sonar records from the interdistributary bay areas of the Mississippi delta (East Bay, Garden Island Bay, and shallow water areas adjacent to Pass à Loutre) have shown widespread subaqueous disturbance of the bottom sediments. These occur in shallow water and on slopes with very low inclinations (0.01°‐0.45°). The morphology of the features is indicative of mass movement processes involving subsidence and downslope translatory movements. The precise conditions under which failure occurs have not been fully documented, but a conceptual model of potential factor interaction can be formulated.

ISSN:0360-8867    

DOI:10.1080/10641197809379793

出版商:Taylor & Francis Group    

年代:1978

数据来源: Taylor

摘要:

Several physical aspects of continuous subbottom profiling are presented, and their relationship to operating characteristics of profiling instruments is discussed. Interpretation of data produced by shallow‐penetration continuous profilers, such as the SONIA system, is a process of transformation of the continuous measurement of the travel times of reflected sound pulses into geologic phenomena. Essentially, the continuous profiler is a geologic tool; interpretation of the data is based on geologic observation and reasoning, irrespective of the further use of the information obtained in applied science. However, interpreters must have sufficient knowledge of the geophysical system and of the equipment design to be in a position to evaluate the significance of their interpretation.

ISSN:0360-8867    

DOI:10.1080/10641197809379794

出版商:Taylor & Francis Group    

年代:1978

数据来源: Taylor

摘要:

The engineering properties of deep continental margin sediments were determined on a worldwide basis. Deep Sea Drilling Project (DSDP) core data and material were utilized from over 900 cores obtained from 89 sites, primarily on the continental margins. Cores were recovered from penetrations to 200 m in water depths averaging 3000 m. Supplementary laboratory testing on selected cores was directed toward determining index properties and shear strength properties of the sediments. The study included a literature review of deep‐sea soil properties, the results of which are to be used by DSDP to evaluate foundation conditions for reentry cones with long casing strings. The results will also be used for a feasibility study of an ultradeepwater marine riser and well‐control system. The marine sediments examined can be divided into three main types: clay, calcareous ooze, and siliceous ooze. Sediment distribution consisted of 48% calcareous ooze, 43% clay, 6% siliceous ooze, and 3% volcanic ash. Because of the sample disturbance inherent in the deepwater coring operation, emphasis was placed on analyzing sediment properties not significantly affected by changes inin situstresses and structure caused by sampling. Averages and ranges in values of water content and unit weight are presented for the three main sediment types. Plasticity and strength characteristics are discussed in detail and the elastic and compression properties are outlined. The geotechnical properties of deep continental margin soils are summarized.

ISSN:0360-8867    

DOI:10.1080/10641197809379795

出版商:Taylor & Francis Group    

年代:1978

数据来源: Taylor

摘要:

Proceedings of the first International Conference, Behavior of Off‐shore Structures (BOSS ‘76), Norwegian Institute of Technology, Trondheim.Obtainable from The Foundation of Scientific and Industrial Research, University of Trondheim, for N.kr 400 (about $77.00), or from Pergamon Press, Oxford, England, or Fairview Park, New York, for $100.00/volume: vol. 1, 100 pp., vol. 2, 676 pp.

ISSN:0360-8867    

DOI:10.1080/10641197809379796

出版商:Taylor & Francis Group    

年代:1978

数据来源: Taylor

ISSN:0360-8867    

DOI:10.1080/10641197809379790

出版商:Taylor & Francis Group    

年代:1978

数据来源: Taylor