A study on interaction of asperilies based on laboratory and numerical experimets

基于实验室和数值实验的星体相互作用研究

• 批准号: 14540392
• 负责人: YOSHIDA Shingo
• 金额: $ 2.43万
• 依托单位: The University of Tokyo
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2002
• 资助国家: 日本
• 起止时间: 2002 至 2003
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-14540392/
• 关键词: asperity; aseismic slip; episodic slow slip; interaction; rate-and state-dependent friction law

We studied various slip modes on a plate boundary on the basis of a two-degree-of-freedom block-spring model and large-scale biaxial experiments. Slip experiments were conducted using large granite blocks with a pre-existing fault surface of 100 cm in length. Velocity-strengthening friction was given over a half of the fault length by inserting a thin Teflon sheet, while the other half retained velocity-weakening friction of the bare rock surface. Under a loading at a constant velocity, dynamic stick-slip repeated on the velocity-weakening region, causing afterslip on the velocity-strengthening region. The velocity-strengthening region experienced small coseisic slip as well, with the magnitude decreasing with the distance from the velocity-weakening region. The behaviors observed in the laboratory experiments were quantitatively simulated by a two-degree-of-freedom block-spring model, in which two blocks (Block 1 and Block 2) are connected by a liner spring and driven by a slowly moving driver. The friction on each block was assumed to obey rate and state dependent friction law. When a-b was assumed to be negative for Block 1, and positive for Block 2, afterslip occurred at Block 2. This model can also reproduce wide spectrum of slip modes observed on a plate-boundary, including episodic slow slip.

我们基于二自由度块弹簧模型和大规模双轴实验研究了板边界上的各种滑移模式。滑移实验是使用预先存在长度为 100 厘米的断层面的大型花岗岩块进行的。通过插入薄的聚四氟乙烯片，在断层长度的一半以上提供速度增强摩擦，而另一半则保留裸露岩石表面的速度弱化摩擦。在恒速加载下，弱速区反复发生动力粘滑，而强速区则产生后滑。速度加强区也经历了较小的同震滑移，其幅度随着距速度弱化区的距离而减小。通过二自由度块弹簧模型对实验室实验中观察到的行为进行定量模拟，其中两个块（块1和块2）通过线性弹簧连接并由缓慢移动的驱动器驱动。假设每个块上的摩擦遵循速率和状态相关的摩擦定律。当假设 a-b 对于区块 1 为负值，对于区块 2 为正值时，后滑发生在区块 2 处。该模型还可以再现在板块边界上观察到的广泛滑移模式，包括间歇性慢滑移。

项目成果

加藤尚之: "プレート境界面の摩擦パラメーターの推定について-三陸沖のアスペリティを例として-"地学雑誌. 112・6. 857-868 (2003)

加藤直之：“板块界面摩擦参数的估计 - 以三陆海岸的粗糙度为例 -”地质杂志 112・6（2003）。

加藤尚之: "プレート境界面の摩擦パラメターの推定について-三陸沖のアスペリティを例として-"地学雑誌. 112・6. 857-868 (2003)

加藤直之：“板块界面摩擦参数的估计 - 以三陆海岸的粗糙度为例 -”地质杂志 112・6（2003）。

Kato, A., S.Yoshida, M.Ohnaka, H.Mochizuki: "The dependence of constitutive properties on temperature and effective normal stress in seismogenic environment"Pure, Appl.Geophys.. (in press). (2003)

Kato, A.、S.Yoshida、M.Ohnaka、H.Mochizuki：“地震环境中本构特性对温度和有效正应力的依赖性”Pure，Appl.Geophys..（出版中）。

Yoshida, S., N.Kato: "Episodic aseismic slip in a two-degree-of-freedom block model"Geophys.Res.Lett.. 30. 1681,doi:10.1029/2003GL017439 (2003)

Yoshida, S., N.Kato：“二自由度块体模型中的情景抗震滑移”Geophys.Res.Lett.. 30. 1681，doi:10.1029/2003GL017439 (2003)

Yoshida, S., N.Kato: "Episodic aseismic slip in a two-degree-of-freedom block model"Geophys.Res.Lett.. 30. 1681,doi:10.1029-2003GL017439 (2003)

Yoshida, S., N.Kato：“二自由度块模型中的情景抗震滑移”Geophys.Res.Lett.. 30. 1681，doi:10.1029-2003GL017439 (2003)