不同类型俯冲带地震竖向地震动阻尼修正系数对比研究

俯冲带地区竖向地震动的阻尼修正系数在工程结构抗震设计中起着重要作用。由于俯冲带地区的板块构造复杂，俯冲带地区的地震可划分为浅壳上地幔地震、板内地震和板间地震3种类型。为研究不同类型俯冲带地震的竖向地震动阻尼修正系数间是否具有显著差异而需要分别建立不同的阻尼修正系数模型，采用日本俯冲带地区的地震动数据，通过假设检验和构造差异指标的方式对不同类型地震的竖向加速度和位移反应谱的阻尼修正系数进行两两比较。结果显示:不同地震类型的竖向地震动阻尼修正系数在众多谱周期上存在统计意义和工程实际意义上的显著差异。该研究表明:研究俯冲带地区竖向地震动阻尼修正系数时需要考虑地震类型的影响。

Comparison of damping modification factors for the vertical ground motions of different earthquake types in subduction zones

The damping modification factors for the vertical ground motions in subduction zones are important for the seismic design of engineering structures. The tectonic setting in the subduction zone is complex, and the earthquakes in the subduction zone can be divided into three types:shallow crustal and upper mantle, subduction interface and subduction slab earthquakes. The strong ground-motion records from subduction zones in Japan were used to evaluate the effects of earthquake types on the damping modification factors for the acceleration and displacement response spectra. It is found from the statistical tests that the differences between the damping modification factors for different earthquake types are statistically and practically significant at many spectral periods. It is indicated by this study that the effects of earthquake types should be taken into accout to derive damping modification factors for the vertical ground motions in the subduction zone.