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. Rosakis 高度仪器化的实时动态理想化实验正在实验室中用于模拟地震，以全面了解控制地震破裂的基本物理现象。 实验室实验是通过创建由 Homalite-100 或聚碳酸酯制成的理想二维模型来进行的。 这些材料是双折射的，可以使用动态光弹性光学技术。 通过高速摄影（每秒 200 万帧）捕获并记录整个实验事件中的光弹性条纹图案，从而能够推断实时全场应力场演化。 定制的高速红外相机（每秒 100 万帧）也被用于对破裂引起的热场进行成像。 动态样品加载是通过气枪发射弹丸冲击或爆炸线系统来完成的。 具体研究领域包括：（1）破裂扩展的性质（裂纹状与脉冲状）； (2) 破裂速度可实现范围的实验验证（限制为材料剪切波速度与超剪切的~0.8倍）； (3) 确定不均匀地壳断层的特性差异（例如波速）在多大程度上促进了破裂的方向性； (4) 跨越阶梯式断层或缓进式断层的破裂条件（例如破裂的连续触发、跳跃或减慢）； (5) 调查断层弯曲或分支上发生的破裂是否传播、减缓、停止或分叉形成新的断层面； (6)沿活动断层摩擦散热、粗糙加热、局部熔化和润滑的性质。