Rock Friction Constitutive Experiments as Related to Theory of Earthquake Instability

9220005 Tullis这项工作是对岩石摩擦行为的实验室实验研究，对理解基本摩擦过程和学习如何将实验室结果应用于产生地震的地壳断层具有重要意义。重点放在两个重要问题上。第一个是理解对观察到的行为负责的过程，这样本构方程就可以基于已知的过程。这对于在大的时间和距离尺度上推断地震的实验室结果是重要的。第二个问题是理解在大位移实验中，初始裸表面摩擦试件的速度衰减行为和模拟断层泥试件的速度增强行为之间存在差异的原因。了解这些样本中摩擦行为和结构之间的相关性将有助于确定哪些行为可能与在自然断层中观察到的结构有关。实验将使用一种独特的适用于此目的的高压旋转剪切仪进行。实验将在具有已知流动和裂缝特性的地质重要性岩石类型上进行。孔隙流体化学、滑动速率和温度将被改变，以确定摩擦行为如何依赖于这些变量，并帮助识别操作过程。***

9220005 Tullis This work is a laboratory experimental study of the frictional behavior of rocks with significance both for understanding fundamental frictional processes and for learning how to apply the laboratory results to faults in the Earth's crust that produce earthquakes. The focus is on two important problems. The first is to understand the processes responsible for the observed behavior, so that constitutive equations can be based on known processes. This is important for extrapolating laboratory results over large time and distance scales to earthquakes. The second problem is to understand the reason for differences in large displacement experiments between velocity weakening behavior of friction samples using initially bare surfaces and velocity strengthening behavior of samples using simulated gouge. Understanding the correlations between frictional behavior and structures in these samples will help ascertain what behavior may be associated with structures observed in natural faults. Experiments will be conducted using a unique high pressure rotary shear apparatus well suited for this purpose. Experiments will be done on rock types of geological importance with known flow and fracture properties. Pore fluid chemistry, sliding rate and temperature will be varied to determine how frictional behavior depends on these variables and to help identify operative processes. ***