摘要:

Eastern Taiwan is located on the tectonically active suture zone between the Eurasian plate and the Philippine Sea plate. In addition to the steep slopes, abundant fault structures and frequent earthquakes cause ubiquitous slumps and slides on the continental slope. To provide a basis for the quantitative analysis of the slumping, laboratory tests were performed on undisturbed core samples from the Changyuan offshore area to examine their physical and geotechnical properties.

ISSN:1064-119X    

DOI:10.1080/10641199709379945

出版商:Taylor & Francis Group    

年代:1997

数据来源: Taylor

摘要:

This article describes a laboratory testing program on a very soft, fine‐grained coastal sediment to investigate methods for characterizing both the physicochemical properties of the sediment and its stress‐strain‐strength properties in the laboratory. The very soft consistency of these coastal sediments presents a significant obstacle to obtaining valid mechanical properties from laboratory tests. Such properties are needed to develop constitutive models for interpretation of in‐situ tests, prediction of penetrating object behavior, and estimation of landslide and erosion potential. After physical and chemical characterization, the sediment from the Gulf of Mexico was tested using one‐dimensional consolidation and consolidated‐undrained triaxial and direct simple shear tests. Testing problems associated with the high compressibility and low strength of this material were identified and some solutions developed to mitigate their effects. The results indicate that, while better sampling procedures need to be developed, consistent consolidation and. stress‐strain‐strength parameters can be obtained. However, special testing considerations are vital, including innovative tube extrusion and specimen trimming procedures to minimize sample disturbance, high‐precision measurement instrumentation, and comprehensive error analysis to correct measured behavior. The article recommends additional research that is vital in order to reach more definitive and widely applicable conclusions about coastal sediment behavior.

ISSN:1064-119X    

DOI:10.1080/10641199709379946

出版商:Taylor & Francis Group    

年代:1997

数据来源: Taylor

摘要:

High‐resolution vertical and lateral gradients and variations in sediment mass physical properties were derived from measurements in box cores, on the scale of millimeters, tens of centimeters, and kilometers from typical, relatively broad areas of the northern California continental slope in the Cape Mendocino area at water depths from 380 to 940 m. Such data are important as a control on comparisons of different sediment suites, as well as providing limits for realistic flux calculations of dissolved inorganic and biochemical species and pollutants. The sediments studied have relatively constant organic carbon contents (OC ? 1.75 wt%) and bulk mineralogy. They range from silty sands (∼45% sand, 40% silt) to clayey silts (∼63% silt, ∼35% clay) and are extensively bioturbated. Physical property variations between subcores (∼25 to 35 cm in length), taken from the same box core, increase with increasing clay content. For coarse‐grained sediments, mean down‐core differences in physical property values between related subcores are small, averaging 3.6% for water content, 4% for porosity, 0.026 Mg/m3for wet bulk density, and 0.1 for void ratio. Subcore variations for fine‐grained sediments are generally significantly larger, averaging 9.8% for water content, 1.52% for porosity, 0.027 Mg/m3for wet bulk density, and 0.3 for void ratio (box core 125). Millimeter variations of physical properties from horizontal 12‐cm‐long subcores indicate a maximum range of lateral variation of 18.2% for water content, 8% for porosity, 0.14 Mg/m3for wet bulk density, and∼0.6 for void ratio.

ISSN:1064-119X    

DOI:10.1080/10641199709379948

出版商:Taylor & Francis Group    

年代:1997

数据来源: Taylor

ISSN:1064-119X    

DOI:10.1080/10641199709379944

出版商:Taylor & Francis Group    

年代:1997

数据来源: Taylor