Static and Cyclic Shear Strength of Cohesive and Non-cohesive Sediments
Static and Cyclic Shear Strength of Cohesive and Non-cohesive Sediments
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粘性和非粘性沉积物的静态和循环剪切强度
DOI：
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发表时间：
2012
期刊：
影响因子：
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通讯作者：
A. Kopf
中科院分区：
文献类型：
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作者：
G. Wiemer;A. Reusch;M. Strasser;S. Kreiter;Daniel R. Otto;T. Mörz;A. Kopf
海底斜坡破坏是常见的沿着构造和地震活跃的边缘，并可能对陆上和海上基础设施以及沿海社区造成破坏性影响。与静态加载相比，土壤对周期性加载的反应是可变的--这使得海底斜坡稳定性和质量运动启动研究必须进行静态和循环加载实验。结果（一）一般研究调查排水静态与不排水循环荷载下的水饱和沉积物的剪切强度，并从（ii）与天然样品的比较。直接剪切仪和MARUM动态三轴试验装置已被用来比较不排水，循环排水，静态剪切强度与不同的粘土，石英（桑迪粉土）比例的重组样品。通过这个实验装置，我们的目的是确定在循环和静态载荷条件下的粘性颗粒材料的破坏潜力。结果表明，粘土矿物含量小于20%的材料混合物的循环剪切强度显着低于其静态剪切强度。粘土矿物含量超过20%的混合物表现出收敛的循环，不排水和静态，排水剪切强度。正在进行的研究以从通用端元测试中获得的知识为基础，并整合了来自南海海槽增生楔（日本）的天然样本。
Submarine slope failures are common along tectonically and seismically active margins and may have devastating impact on onshore and offshore infrastructure as well as coastal communities. Soils show a variable response to periodic loading compared to static loading – making static and cyclic loading experiments compulsory for submarine slope stability and mass-movement initiation studies. Results from (i) a generic study investigating the shear strength of water-saturated sediments upon drained static vs. undrained cyclic loading, and from (ii) a comparison to natural samples are presented. A direct shear apparatus and the MARUM Dynamic Triaxial Testing Device have been used to compare undrained, cyclic to drained, static shear strengths of reconstituted samples with different clay to quartz (sandy silt) ratios. With this experimental set-up we aim to identify the failure potential of cohesive to granular material under cyclic and static loading condition. Results indicate that the cyclic shear strengths of material mixtures with less than 20% clay mineral content are significantly lower than their static shear strengths. Mixtures with a clay mineral content exceeding 20% show converging cyclic, undrained and static, drained shear strengths. Ongoing studies build on the knowledge gained from the generic endmember tests and integrate natural samples from the Nankai Trough accretionary wedge (Japan).