Laboratory Studies of Earthquake Dynamics

地震动力学实验室研究

• 批准号: 0207873
• 负责人: Ares Rosakis
• 金额: $ 21.99万
• 依托单位: California Institute of Technology
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-07-15 至 2005-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0207873&HistoricalAwards=false
• 关键词: Laboratory; Studies; Earthquake; Dynamics

EAR-0207873Ares J. RosakisHighly instrumented, real-time, dynamic idealized experiments are being used to model earthquakes in the laboratory towards a comprehensive understanding of the basic physical phenomena governing earthquake rupture. Laboratory experiments are performed by creating idealized two-dimensional models made of Homalite-100 or polycarbonate. These materials are birefringent, enabling the use of the optical technique of dynamic photoelasticity. Photoelastic fringe patterns are captured and recorded throughout experimental events by high-speed photography (2 million frames per second), enabling the inference of real-time full-field stress field evolution. A custom high-speed infrared camera (1 million frames per second) is also being used to image thermal fields due to rupture. Dynamic specimen loading is accomplished by gas gun fired projectile impact or by an exploding wire system. Specific areas of study are: (1) nature of rupture propagation (crack-like vs. pulse-like); (2) experimental verification of the achievable range of rupture speed (limited to ~0.8 times the material's shear wave speed vs. supershear); (3) determination to what extent differences in properties (e.g., wave speeds) across inhomogeneous crustal faults promote directionality of rupture; (4) conditions of rupture across step-overs or jogs in en echelon faults (e.g., successive triggering, jumping, or slowing down of ruptures); (5) investigation of whether ruptures incident on fault bends or branches get transmitted, slow down, arrest, or bifurcate creating new fault surfaces; (6) nature of frictional heat dissipation, asperity heating, local melting, and lubrication along active faults.

EAR-0207873ARES J. ROSAKISHIGHLALE仪器，实时，动态理想化的实验已用于对实验室中的地震进行建模，以全面了解控制地震破裂的基本物理现象。 实验实验是通过创建由人类100或聚碳酸酯制成的理想化的二维模型来进行的。 这些材料是双折的，因此可以使用动态光弹的光学技术。 光弹性条纹图案通过高速摄影（每秒200万帧）捕获并记录在整个实验事件中，从而推断了实时全场应力场演化。 由于破裂，定制的高速红外摄像头（每秒100万帧）也用于对热场进行图像。 动态标本负载是通过燃气枪弹丸冲击或爆炸线系统来完成的。 研究领域是：（1）破裂传播的性质（类似于脉冲的裂纹）； （2）可实现的破裂速度范围的实验验证（限制为材料的剪切波速度与超透态的〜0.8倍）； （3）确定在跨多种程度的性质（例如，波速）跨不同均匀的地壳断层的差异促进破裂的方向性； （4）跨阶段或慢跑的破裂条件（例如，连续的触发，跳跃或减慢破裂的速度）； （5）调查发生在断层弯曲或分支上的破裂是否会传播，放慢，逮捕或分叉产生新的断层表面； （6）摩擦热量散热的性质，浅层加热，局部熔化和沿活动断层润滑的性质。