基于Newmark模型的地震滑坡概率危险性分析——以南迦巴瓦地区为例

Probability Hazard Analysis of Earthquake-induced Landslides Based on the Newmark Model: A Case Study in Namche Barwa Area

摘要:

潜在地震滑坡的概率危险性分析主要是将概率地震危险性分析和Newmark位移模型相结合,以滑坡失稳概率为危险性指标,给出潜在地震滑坡的危险性区划结果。根据南迦巴瓦地区工程地质岩性及地形高程数据,参考第五代地震动参数区划图结果,本文给出了研究区50年10%超越概率水平下潜在地震滑坡的失稳概率。根据所得结果将南迦巴瓦地区潜在地震滑坡的概率危险性划分为低危险区 (P (f) ≤0.2) 、中危险区 (0.2＜P (f) ≤0.3) 和高危险区 (0.3＜P (f) ≤0.4) ,其中, 中、高危险区主要分布于南迦巴瓦峰附近以及沿雅鲁藏布江、帕隆藏布江、则普曲和金珠藏布江等河谷两侧坡度较大的区域。本文研究结果可为区域地震地质防灾规划和应急预案制定提供依据,为重大工程建设安全提供参考和建议。

Abstract:

The probabilistic hazard analysis of potential earthquake-induced landslides integrates probabilistic seismic hazard analysis with the Newmark displacement model,using the probability of slope failure as the hazard index to produce zoning maps of landslide susceptibility. This study assesses the Namche Barwa region by incorporating engineering geological lithology and topographic elevation data,along with seismic ground motion parameters from China's fifth-generation seismic zoning map. The analysis estimates the probability of landslide occurrence under a 10% probability of exceedance over a 50-year period. Based on the results,the region is categorized into low-hazard zones ( P (f) ≤0.2),moderate-hazard zones (0.2＜ P (f) ≤0.3),and high-hazard zones (0.3＜ P (f) ≤0.4) . Moderate and high-hazard areas are primarily concentrated near Namche Barwa Peak and along steep valley slopes adjacent to major rivers,including the Yarlung Zangbo,Parlung Zangbo,Zepu Qu,and Jinzhu Zangbo rivers. These findings provide a scientific basis for regional seismic landslide risk mitigation,emergency preparedness planning,and the safety assessment of major infrastructure projects in the area.