The Physics of Gouge-Filled Fault Zones

阿哈罗诺夫在断层上滑动时，滑动面会被磨损，并堆积一层地面岩石或断层泥。实验室实验表明，断层泥可以改变断层的性质，如摩擦、滑动稳定性和强度。了解这些性质的演化和状态对于定量了解断裂过程是至关重要的。P.I.将使用离散元方法的一种变体进行数值研究：在该模型中，被剪切的颗粒层的整体特性是许多单独颗粒之间离散相互作用的结果。他们将研究剪切泥中的表观摩擦和屈服应力与粒间摩擦、法向应力、剪胀和滑移速度之间的关系。他们还将探索刨削和加工区的时间和空间演变(例如，粗糙度和粒度分布的演变)以及滑移局部化的机制。

9804855AharonovDuring slip on faults, sliding surfaces are worn and a layer of ground rock, or fault gouge, accumulates. Laboratory experiments indicate that gouge can change fault properties such as friction, sliding stability, and strength. An understanding of the evolution and state of these properties is essential for quantitative understanding of faulting processes. The P.I.s will conduct a numerical study using a variant of the discrete element method: in this model the bulk properties of a sheared layer of grains are the consequence of discrete interactions between many individual grains. They will investigate the relations between apparent friction and yield stress, and interparticle friction, normal stress, dilatancy and slip velocity in sheared gouge. They will also explore the temporal and spatial evolution of gouge and process zones (e.g. evolution of roughness and grain-size distributions) and the mechanics of slip localization.