THE ROLES OF TIME AND DISPLACEMENT IN THE EVOLUTION EFFECT IN ROCK FRICTION
THE ROLES OF TIME AND DISPLACEMENT IN THE EVOLUTION EFFECT IN ROCK FRICTION
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DOI：
10.1029/94gl01599
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发表时间：
1994-09-01
影响因子：
5.2
通讯作者：
WEEKS, JD
中科院分区：
文献类型：
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作者：
BEELER, NM;TULLIS, TE;WEEKS, JD
石英岩的室温摩擦实验服从强度对速度的依赖关系，它由两个相反的效应组成。这些效应中的第二个与速度负相关，并且在特征位移上演化。这种演化效应最初由Dieterich[1978；1979]归因于潜在的依赖于时间的过程，但通常用两个经验演化定律中的一个来描述。一种是显式地依赖于位移(滑移定律)，另一种是保持时间依赖性(慢度定律)。在速度步进实验中，滑移定律在描述稳态附近的行为时更受青睐。然而，在本研究中，在不同机器刚度下进行的滑动-保持-滑动测试表明，进化效应依赖于时间，而不是滑动。对于慢度定律，在滑动-保持-滑动试验中直接测量了随时间变化的强化系数b。现有的经验演化定律可能不足以同时描述近稳态和非稳态行为。如果能找到一种更正确的形式，时间相关演化可能会通过减少地震间滑移量来改进地震旋回的摩擦模型。
Room temperature friction experiments on quartzofeldspathic rocks obey a velocity dependence of strength which consists of two opposite-sensed effects. The second of these effects has a negative velocity dependence and evolves over a characteristic displacement. This evolution effect was originally attributed by Dieterich [1978; 1979] to an underlying time-dependent process but is often described by either of two empirical evolution laws. One depends explicitly on displacement (slip law) and the other retains time dependence (slowness law). The slip law is favored in representing behavior around steady-state as seen in velocity stepping experiments. However, in this study slide-hold-slide tests conducted at different machine stiffnesses show that the evolution effect depends on time, not slip. For the slowness law the coefficient of time-dependent strengthening b is measured directly in slide-hold-slide tests. Existing empirical evolution laws may not be sufficient to describe both near steady-state and non steady-state behavior. Provided a more correct form can be found, time-dependent evolution may improve frictional models of the seismic cycle by reducing the amount of inter-seismic slip.