| 玉树地震震前甘孜—玉树断裂局部应力场时空偏转特征的离散元模拟研究 |
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| 关键词:Yushu earthquake Ganzi–Yushu fault discrete element local stress field deflection angle |
| 基金项目:中央高校基本科研业务费研究生科技创新项目(编号: ZY20220319);国家自然科学基金项目(编号: 41807270);中央高校基本科研业务费专题研究重点项目(编号: ZY20215113) |
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| Discrete Element Modeling of the Spatiotemporal Deflection Characteristics of the Local Stress Field of the Ganzi–Yushu Fault before the Yushu Earthquake |
| Regional tectonic activities alter the stress state of the crust, and tectonic earthquakes are extreme regional tectonic activities. Therefore, understanding the change in the local stress field of seismogenic faults before earthquakes occur has great significance in the characterization of fault activities. This study used the particle discrete element package PFC2D and monitoring data of the YRY-4 borehole strain gauge at the Yushu Seismic Station to simulate the spatiotemporal deflection characteristics of the maximum principal stress direction in the local stress field before the Yushu MS7.1 earthquake on April 14, 2010, and the Ganzi–Yushu strike-slip fault. The results showed that the SH direction of the maximum horizontal principal stress at the Yushu station before the earthquake displayed counterclockwise deflection. The deflection gradually recovered after a certain amount of strain energy had accumulated. The change pattern of the simulated local stress direction was generally consistent with the field observation results. The variation pattern of SH differed at different positions of the fault, and the disturbance of local stress was more obvious with nearer proximity to the fault structure. The SHT located in the tensile stress concentration area and the SHP located in the compressive stress concentration area rotated simultaneously toward the boundary direction of the two areas. The deflection angle increased gradually with increasing time step. The degree of stress accumulation varied among different regions and increased with loading time. Fractures occurred at different times, with obvious spatiotemporal asynchronous effects. |
| ZHANG Tao,SU Zhandong,SUN Jinzhong,ZHANG Jianyong,TANG Lei,ZHOU Jian,WANG Lei,ZHANG Minglei.2024.Discrete Element Modeling of the Spatiotemporal Deflection Characteristics of the Local Stress Field of the Ganzi–Yushu Fault before the Yushu Earthquake[J].Acta Geoscientica Sinica,45(2):203-216. |
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