西藏定日6.8级地震地面运动特征空间分布分析

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中图分类号：TP18；P315.9 文献标志码：A 文章编号：1000-0844（2025）05—1175—14

DOI：10.20000/j.1000-0844.20250221001

Abstract： At O9：O5 Beijing Time on January 7，2025，an M6.8 earthquake struck Dingri County，Shigatse， Xizang Autonomous Region，causing casualties and property damage. In this study，35 sets of ground motion records of this event were obtained from the Strong Motion Observation Center of the Institute of Engineering Mechanics，China Earthquake Administration，and horizontal and vertical acceleration response spectra were drawn after baseline correction and filtering of the raw data. A systematic analysis was then conducted encompassing the spatial distributions of the peak ground acceleration （PGA） and spectral acceleration at 0.2 s [Sa（0.2s）] as well as generalized intensity parameters including the cumulative absolute velocity （CAV），Arias intensity （IA） ），and significant duration （Ds） ）. The results were used to identify the pulse characteristics in three-component ground motions. The earthquake was found to induce significant damage to structures with natural periods of O.2—O.7 s； the north-south acceleration response spectrum recorded at station XZ.Doo07 （Lhazé County） exceeded the design spectrum threshold for extremely rare earthquakes （intensity 8）. CAV and IA exhibited similar spatial distribution patterns in the horizontal and vertical directions. CAV values at station XZ.Doo04 （Dingjie County） and XZ. D0007（Lhazé County），along with the IA value at station XZ.Dooo7，exceeded regulatory thresholds. Ground motions displayed typical hanging-wall/footwall effects where Sa（0.2s） and PGA were higher but had shorter durations on hanging walls. No pulse-like ground motions were identified based on Baker's pulse characterization criterion. This study provides a scientific basis for revealing the intensity distribution characteristics of ground motions and is expected to serve as a reference for future aseismic fortification of engineering structures in Xizang.

Keywords： Dingri M6.8 earthquake; ground motion; spatial distribution; response spectrum; intensity parameters

0 引言

北京时间2025年1月7日9时5分，中国西藏自治区日喀则市定日县发生6.8级强烈地震。（剩余18747字）