甘肃积石山Ms 6.2地震对滑坡易发区的变形影响分析

Deformation Analysis of the Ms 6.2 Jishishan (Gansu,China) Earthquake on the Landslide Hazard Areas

  • 摘要: 地震极易诱发或加速滑坡灾害发生,2023-12-18甘肃积石山县发生Ms 6.2地震,震源深度仅为10 km,周边滑坡易发区面临突发性破坏甚至提前发生灾害的风险,亟需对易发区变形进行快速分析与评估。基于此,采集了积石山地震远场不同距离(64 km、111 km、140 km和240 km)的4处滑坡隐患区全球导航定位系统(global navigation satellite system,GNSS)和加速度计实时监测数据,采用精密单点定位、实时动态差分定位技术、GNSS加速度计自适应融合技术以及小波变换等方法综合分析了主震和余震对边坡体的破坏性影响。研究结果表明,距震中64 km的黑方台滑坡体监测到1 cm的弹性位移以及0.5 cm的永久形变,距震中240 km的舟曲滑坡体监测到明显的加速度冲击事件,捕捉到的地表振动频率在0~10 Hz之间,加速度峰值达0.035 m/s²,增加了滑坡易发区的失稳风险。此次地震对滑坡造成的位移和振动影响在水平方向上较为显著。建议相关部门尽快对震源64 km范围内的滑坡易发区进行勘察和评估,避免突发性滑坡灾害的发生。

     

    Abstract:
    Objectives Earthquake events can easily induce or accelerate the landslide failure. On 18th December 2023, an Ms 6.2 earthquake occurred in Jishishan County, Gansu province, with a focal depth of only 10 km. The surrounding landslide disaster-prone areas are faced with great hidden danger of sudden or advanced failure, and it is urgent to conduct rapid analysis and assessment of deformation in prone areas.
    Methods In this paper, the global navigation satellite system(GNSS)and accelerometer real-time observation data of four landslide prone areas at different distances (64 km, 111 km, 140 km and 240 km) from the seismic center, and the damage effects of the main shock and aftershock on the landslide were comprehensively analyzed with precise point positioning, real-time kinematic, GNSS & accelerometer adaptive coupled technology and wavelet transform.
    Results The results show that the elastic displacement of 1 cm and the permanent displacement of 0.5 cm aredetected in the Heifangtai landslide, 64 km away from the seismic center, while the obvious impact responses are detected in the Zhouqu landslide, 240 km away from the seismic center. The vibration frequency was between 0‐10 Hz, and the peak acceleration reached 0.035 m/s², which increased the risk of landslide failure.
    Conclusions The displacement and vibration effects of the earthquake on the landslide are mainly concentrated in the horizontal direction, and the vertical direction is not significant. It is suggested the landslide disaster-prone areas within 64 km of Jishishan County should be investigated and evaluated as soon as possible to prevent secondary disaster damage.

     

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