• ISSN 2097-1893
  • CN 10-1855/P
纪志伟,陈学良,张波. 2022. 漾濞MS6.4地震长周期强地震动的有限差分初步模拟. 地球与行星物理论评,53(1):85-91. doi: 10.19975/j.dqyxx.2021-039
引用本文: 纪志伟,陈学良,张波. 2022. 漾濞MS6.4地震长周期强地震动的有限差分初步模拟. 地球与行星物理论评,53(1):85-91. doi: 10.19975/j.dqyxx.2021-039
Ji Z W, Chen X L, Zhang B. 2022. Preliminary finite difference simulation of long-period strong ground motions for the Yangbi MS6.4 earthquake. Reviews of Geophysics and Planetary Physics, 53(1): 85-91. doi: 10.19975/j.dqyxx.2021-039
Citation: Ji Z W, Chen X L, Zhang B. 2022. Preliminary finite difference simulation of long-period strong ground motions for the Yangbi MS6.4 earthquake. Reviews of Geophysics and Planetary Physics, 53(1): 85-91. doi: 10.19975/j.dqyxx.2021-039

漾濞MS6.4地震长周期强地震动的有限差分初步模拟

Preliminary finite difference simulation of long-period strong ground motions for the Yangbi MS6.4 earthquake

  • 摘要: 根据我国川滇地区的地质地貌特征、前人地质资料和2021年漾濞MS6.4地震的震源参数初步反演结果,建立三维速度结构模型,采用三维有限差分法对漾濞地震的长周期地震动进行研究. 对实际地震烈度和模拟烈度进行对比,同时在区域附近布置了36个观测点,给出其中6个观测点的三分量速度时程,并给出所有观测点阻尼比为5%的速度反应谱,结果表明:(1)模拟的速度峰值已超过25 cm/s,与实际漾濞地区附近的烈度为8度吻合;(2)受断层滑动分布影响,速度水平分量在西北方向分布范围更广,衰减速度明显慢于东南方向,并且在极震区,东北—西南方向的地震动衰减也较慢. 方向性效应对峰值大小及其分布范围的影响显著;(3)观测点速度反应谱的特征周期分布在1~3 s范围内,可能会因为共振效应对区域附近的大型建筑物产生较为严重的破坏. 需要对漾濞地震进行进一步研究,以期对漾濞地震的长周期地震动有更为细致的认识.

     

    Abstract: According to the geological and geomorphic characteristics of the Sichuan-Yunnan area, previous geological data and the preliminary inversion results of source parameters of the Yangbi MS6.4 earthquake in 2021, we established a three-dimensional velocity structure model and studied the long-period ground motion of the Yangbi earthquake by using the three-dimensional finite difference method. Meanwhile, we arranged 36 observation points in and around the Yangbi earthquake area and obtained the velocity response spectra of all observation points with a damping ratio of 5%. The three-component velocity time histories of 6 observation points are also given, The results show that: (1) the simulated velocity peak has exceeded 25 cm/s, which is consistent with the intensity of 8 near the actual Yanghe area; (2) Affected by the distribution of fault slip, the horizontal component of velocity is more widely distributed in the northwest, and the attenuation speed is significantly slower than that in the southeast. In the meizoseismal region , the attenuation of ground motion from the northeast to southwest is also slower. The directivity effect has a significant effect on the peak value and distribution range; (3) The characteristic period of velocity response spectrum of observation points are distributed in the range of 1 ~ 3 s, which may cause serious damage to large buildings near the area due to resonance effect. It is necessary to further study the Yangbi earthquake to have a more detailed understanding of the long-period ground motion of the Yangbi earthquake.

     

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