基于Newmark模型的概率地震滑坡危险性分析方法研究

Probabilistic seismic slope displacement hazard analysis based on Newmark displacement model:Take the area of Tianshui,Gansu Province,China as an example

  • 摘要: 本文以天水地区为研究区,结合地震潜在震源区模型和Newmark位移预测方程,采用概率地震危险性分析方法,计算了该地区50年超越概率10%水平下的Newmark位移。同时,根据天水地区50年超越概率10%下的阿里亚斯烈度,并结合Newmark位移与阿里亚斯烈度的关系式,计算了天水地区在遭受50年超越概率10%下的阿里亚斯烈度影响时,潜在滑坡体产生的Newmark位移分布。通过比较上述两种方法得到的天水地区不同Newmark位移的分布特征,本文认为二者虽然存在较大差异,但其空间分布特征均能反映天水地区每个场点处的相对滑坡危险性。对滑坡危险性水平进行分区的结果显示,天水地区60%以上的区域具有高地震滑坡危险性,50%以上的区域具有甚高地震滑坡危险性。本文的研究结果可以作为天水地区地震危险性及风险评估的参考资料,也可以作为天水地区城市规划、土地使用规划、地震应急准备以及其它公共政策制定的参考资料。

     

    Abstract: Earthquake-induced landslide is a kind of destructive earthquake secondary disaster, which could cause serious casualties and property damage. The Tianshui area of Gansu Province has suffered severe landslides caused by several strong earthquakes. In this paper, based on the model of potential seismic sources and the prediction equation of Newmark displacement, we adopt the method of probabilistic seismic hazard analysis to study the probabilistic seismic landslide hazard in Tianshui area, and to calculate the values of Newmark displacement under the 10% probability of being exceeded in 50 years. Meanwhile, according to the Arias intensity under the 10% probability of being exceeded in 50 years in Tianshui area, combined with the relationship between Newmark displacement and Arias intensity, we also calculate the Newmark displacement of potential landslides when Tianshui area suffered from the Arias intensity under the 10% probability of being exceeded in 50 years. We compare the two sets of the values of Newmark displacement obtained by these two different methods, and find that there are significant difference, but still can reflect the relative landslide hazard of each site in Tianshui area. According to the results of landslide hazard zoning, more than 60% of the area in Tianshui has high earthquake-landslide hazard, and more than 50% of the region in Tianshui has very high earthquake-landslide hazard. The research results of this paper can be used as the reference materials of seismic hazard and risk assessment of Tianshui area, and can also be used as the reference materials of city planning, land use planning, earthquake emergency preparedness and other public policy making in Tianshui area.

     

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