Anisotropic Deformation-Strength Properties of Soft Sedimentary Rock “Shirasu” Originated From Pyroclastic Flows
Anisotropic Deformation-Strength Properties of Soft Sedimentary Rock “Shirasu” Originated From Pyroclastic Flows
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火山碎屑流引起的软质沉积岩“Shirasu”的各向异性变形强度特性
DOI：
10.3208/sandf1972.24.4_84
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发表时间：
1984
期刊：
影响因子：
--
通讯作者：
R. Kitamura
中科院分区：
文献类型：
--
作者：
Motohisa Haruyama;R. Kitamura
为了研究火山碎屑流沉积岩“白须”的变形-强度特性，对块体切割和修整后的原状试样进行了排水三轴压缩试验。试件的测试方向施加的主要主应力倾斜在不同角度的层面。从试验结果中研究了白砂剪切行为的固有各向异性。各向异性取决于地层倾角和围压，与固结和剪切过程中的颗粒取向和颗粒运动有关。在低围压下，各向异性对剪切行为的影响显著，而在高围压下，各向异性对剪切行为的影响消失。沉积岩的抗剪强度取决于破坏时最大主应力的方向和应力水平，在实际问题中选择强度参数时应特别注意。
In order to study the deformation-strength behaviour of soft sedimentary rock "Shirasu" derived from pyroclastic flows, drained triaxial compression tests were performed on undisturbed specimens prepared by cutting and trimming from block samples. The specimens were tested with the direction of applied major principal stress inclined at various angles to a bedding plane. An inherent anisotropy in the shearing behaviour of Shirasu was studied from the test results. The anisotropy was dependent on the dip of stratum and the confining pressure related to grain orientations and grain movements during consolidation and shearing. The effect of anisotropy on the shearing behaviour was remarkable under a low confining pressure and disappeared under a high confining pressure. That the shearing strength of sedimentary rocks depends on the direction of the major principal stress at failure and the stress level requires a special attention for the choice of the strength parameters in practical problems.