Dry, damp, or drenched? The effect of water saturation on the frictional properties of clay fault gouges
Dry, damp, or drenched? The effect of water saturation on the frictional properties of clay fault gouges
复制标题
干燥、潮湿还是湿透？
DOI：
10.1016/j.jsg.2020.104094
复制
发表时间：
2020
影响因子：
3.1
通讯作者：
Beynon S
中科院分区：
文献类型：
--
作者：
Beynon S
粘土矿物通常占断层岩心的很大比例，但粘土摩擦的物理机制，特别是自由和间隙结合水(夹层)的影响，人们知之甚少。了解这种典型的摩擦较弱成分的行为，对于约束断裂带的更大范围的行为是基本的。在这项研究中，实验室对人工合成粘土断层泥进行了严格控制饱和状态下的实验。在室温下，在三轴压力下，在以下条件下剪切样品：水饱和；室内湿度；热干燥，然后在室内湿度下剪切；在室温湿度的真空中；热干燥，然后在真空中剪切；在真空中，并在压力容器内热干燥。摩擦系数(μ)在2：1的蒙脱石和1：1的片状硅酸盐中随着干燥程度的增加而增加3倍和2倍，最大的增加在热干样品中。对本构摩擦参数(a-b)的分析表明，随着干燥程度的增加，断层泥的稳定性变差。在更干燥的样品中，根据滑动速度(DC)的变化建立新的稳态μ所需的位移或时间显著减少。结果表明，水的存在是促进时间和滑动相关的摩擦变化的关键，将操作的颗粒尺度变形机制限制在那些流体辅助的机制上。它们还强调了研究含粘土材料的摩擦特性的最佳实验室程序。
Clay minerals often constitute a significant proportion of fault cores, yet the physics of clay friction, in particular the effect of free and interstitial bound (interlayer) water, is poorly understood. Understanding the behaviour of this typically frictionally weak component is fundamental to constraining the larger scale behaviour of fault zones. In this study, laboratory experiments were conducted on synthetic clay fault gouges under carefully controlled saturation states. Samples were sheared at room temperature under triaxial pressure at the following conditions: water saturated; room humidity; thermally dried then sheared at room humidity; in a vacuum at room humidity; thermally dried then sheared in a vacuum; in a vacuum and thermally dried within the pressure vessel. Friction coefficient (μ) is shown to increase with ‘dryness’ by a factor of 3 in 2:1 smectite and a factor of 2 in 1:1 sheet silicate, with largest increases in thermally dried samples. Analysis of constitutive frictional parameters (a-b) show that gouges become less stable with ‘dryness’. The amount of displacement or time required to establish a new steady state μ upon a change in sliding velocity (dc) decreases markedly in drier samples. Results suggest that the presence of water is key in promoting time and slip dependent frictional changes, constraining operative grain-scale deformation mechanisms to those that are fluid assisted. They also highlight the optimum laboratory procedures to investigate the frictional properties of clay-bearing materials.
登录
查看更多内容
影响因子：
3.9
作者：
Carpenter, B. M.;Ikari, M. J.;Marone, C.
通讯作者：
Marone, C.
粘土矿物成分和成岩作用：对俯冲带前部断层位置和行为的影响
DOI：
--
发表时间：
2007
期刊：
影响因子：
--
作者：
M. Underwood
通讯作者：
M. Underwood
影响因子：
3.9
作者：
HICKMAN, SH;EVANS, B
通讯作者：
EVANS, B
DOI：
--
发表时间：
1957
期刊：
影响因子：
--
作者：
R. C. Mackenzie
通讯作者：
R. C. Mackenzie
影响因子：
3.9
作者：
Moore, Diane E.;Lockner, David A.
通讯作者：
Lockner, David A.