Mechanics of shear zones in isotropic dilatant materials
Mechanics of shear zones in isotropic dilatant materials
复制标题
各向同性胀流材料中剪切区的力学
DOI：
10.1016/0191-8141(80)90044-9
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发表时间：
1980
影响因子：
3.1
通讯作者：
M. Casey
中科院分区：
文献类型：
--
作者：
M. Casey
本文假定岩石具有线性各向同性的粘性或弹性变形性质，但其模量可能随平均应力而变化。有人认为，剪切带中的岩石应该比周围岩石更弱。建立了剪切带模型，将剪切带表示为具有较低弹性模量或粘性模量的岩石薄片。计算了剪切带相对于区域压缩方向的不同方向的应力。对于脆性破坏，发现剪切区应力的改变有利于进一步开裂，变形是不稳定的。该模型是用来提供一个解释脆性破坏剪切，二阶故障和enéchelon阵列的拉伸断裂。弱带中的平均应力与基质中的平均应力不同，提出在高变质程度变形的岩石中产生剪切带是由于平均应力变化引起的反应使岩石韧性增强所致。
For the present paper it is assumed that rocks have linear isotropic viscous or elastic deformational properties, but their moduli may vary with mean stress. It is argued that the rock in shear zones should be weaker than the surrounding rock. Models of shear zones in which they are represented as sheets of rock with lower elasticity or viscosity modulus are set up. The stresses within the shear zones are calculated for different orientations of the shear zones relative to the regional compression direction. For brittle failure it is found that the modification of the stress in the shear zone can favour further cracking and that the deformation is unstable. The model is used to provide an explanation for brittle failure in shear, second-order faults and en échelon arrays of tension fractures. The mean stress in a weak zone is different from that in the matrix, and it is proposed that shear zones in rocks deformed at high metamorphic grade are caused by ductility enhanced as a result of reactions promoted by changes in mean stress.