MRI: Development of a high pressure and temperature, biaxial deformation apparatus for earthquake and landslide studies

最近对岩石摩擦特性进行的实验室实验表明，断层在地震典型的动态滑动速率下被严重削弱。了解动态减弱的原因和程度对于推进地震滑动事件的成核、破裂传播和能量辐射模式的预测模型至关重要，该模型可以帮助减轻地震和海啸的危险。此时，我们研究动态减弱的能力受到严重限制，因为不存在能够复制地球上地震成核和破裂条件的实验室仪器。该项目将设计、建造和调试一台能够同时达到围压升高、孔隙流体压力和温度升高、滑移率从微米/S到m/S变化以及至少几厘米剪切位移的仪器，以系统地研究地球滑动失稳。该装置将采用一种新型的双轴框架，该框架容纳了一个压力容器，以适应双直接剪切和三轴剪切配置，以及伺服液压和气动加载系统。该仪器将1)推进与减轻与地震相关的自然灾害相关领域的基础研究；2)提供最先进的实验室设施，通过德克萨斯农工大学地球物理岩石力学的综合研究生教育和研究计划，培训下一代研究人员；3)为STEM领域的学生，特别是工程和地球科学的本科生和研究生提供教育和拓展的新机会。对于这个项目，主要研究人员致力于国内和国际研究合作，共享使用新仪器和实验室设施，长期维护设备，并维持重视多样性的研究和教育计划。

Recent laboratory experiments investigating the frictional properties of rock indicate that faults are profoundly weakened at dynamic sliding rates typical of earthquakes. Understanding the cause and extent of dynamic weakening is critical to advance predictive models for nucleation, rupture propagation, and energy radiation patterns of earthquake slip events that can help mitigate the hazards of earthquakes and tsunamis. At this time our ability to investigate dynamic weakening is severely limited because laboratory instruments capable of replicating the conditions of earthquake nucleation and rupture in the Earth do not exist. This project will design, construct, and commission an instrument that can simultaneously achieve the conditions of elevated confining pressure, pore fluid pressure and temperature, variable slip rates from µm/s to m/s, and shear displacements of at least several centimeters to systematically investigate slip instability in the Earth. The apparatus will employ a novel biaxial frame housing a pressure vessel to accommodate double-direct shear and triaxial shear configurations, and servo-hydraulic and pneumatic loading systems. The instrument will 1) advance basic research in areas relevant to mitigating natural hazards associated with earthquakes, 2) provide a state-of-the-art laboratory facility for training the next generation of researchers through an integrated graduate education and research program in geophysical rock mechanics at Texas A&M University, and 3) provide new opportunities for education and outreach to students across the STEM fields, particularly undergraduate and graduate students in engineering and geoscience. With respect to this project, the principal investigators are committed to national and international research collaboration, shared use of the new apparatus and laboratory facilities, long-term maintenance of the equipment, and sustaining a research and education program that values diversity.