• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Journal of geophysical research. Solid earth: JGR >Rapid postseismic strength recovery of Pingxi fault gouge from the Longmenshan fault system: Experiments and implications for the mechanisms of high-velocity weakening of faults
【24h】

Rapid postseismic strength recovery of Pingxi fault gouge from the Longmenshan fault system: Experiments and implications for the mechanisms of high-velocity weakening of faults

机译：龙门山断层系统快速恢复平溪断层地震后强度：实验及对断层高速弱化机理的启示

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Slide-hold-slide tests were conducted on gray blackish gouge (GBG) and yellowish gouge (YG) from Pingxi fault zone to see how rapidly the strength of Longmenshan fault recovers after the 2008 Wenchuan earthquake. Twenty dry runs were made at a normal stress of 0.8 MPa, at a seismic slip rate of 1.4 m/s, and with hold time t_h ranging 0.3-10~5 s. Results exhibit very rapid healing by more than 0.4 in friction coefficient μ in less than 5-10 s, followed by gradual healing in proportion to log(t_h). Healing rates, (increase in μ)/(log (t_h)), during rapid and slow healing are 0.188 and 0.015 for GBG and 0.154 and 0.016 for YG, respectively. The average temperature in the outer half of a 5 μm thick slip zone decreases from 260-300°C to 110-170°C in 5-10 s, and hence, temperature drop appears to be correlated with the rapid healing. Previously reported rapid healing at subseismic slip rates (85-90 mm/s) begins to occur in 10-300 s after the stop of sliding, and this cannot be explained by the cooling of gouge. The difference in healing between subseismic slip rates (delayed and rapid healing) and seismic slip rates (immediate and rapid healing) suggests that the dominant weakening mechanism shifts from tribochemical processes at subseismic slip rates to frictional heating at seismic slip rates. Slip-zone structures are too complex and variable from run to run to reveal microscopic mechanisms for the strength recovery. Rapid healing following seismic slip can be a cause for reduced aftershocks along major coseismic faults.
机译：在平溪断裂带的灰色黑泥（GBG）和黄泥（YG）上进行了滑移-滑移试验，以了解龙门山断裂的强度在2008年汶川地震后恢复得如何迅速。在0.8 MPa的法向应力，1.4 m / s的地震滑移率和保持时间t_h为0.3-10〜5 s的条件下进行了20次空运行。结果显示，在不到5-10 s的时间内，摩擦系数μ的恢复速度非常快，超过0.4，然后逐渐恢复，与log（t_h）成正比。快速和慢速愈合期间，GBG的治愈率（以μ为单位增加）/（log（t_h））分别为GBG和YG的治愈率分别为0.188和0.015。 5μm厚滑移区的外半部分中的平均温度在5-10 s内从260-300°C降至110-170°C，因此，温度下降似乎与快速愈合相关。先前报道的在滑动停止后的10-300 s内开始以亚地震滑动速率（85-90 mm / s）迅速恢复，这不能用冷却凿子来解释。亚地震滑动率（延迟和快速恢复）和地震滑动率（立即和快速恢复）之间的愈合差异表明，主要的减弱机制从亚地震滑动率下的摩擦化学过程转变为地震滑动率下的摩擦加热。滑移区结构过于复杂，并且每次运行都变化很大，无法揭示强度恢复的微观机制。地震滑动后的快速愈合可能是减少沿主要同震断层的余震的原因。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号