竖向与水平向地震动峰值加速度比值V/H的影响因素探究

Research on Influence Factors of Ratio of Vertical and Horizontal Peak Ground Acceleration V/H

根据收集到的来自美国西部和中国台湾集集地震的849条三分量强震记录,筛选并计算了竖向地震峰值加速度与水平向地震峰值加速度之比,分别探讨场地类别、震中距以及震级等因素对峰值加速度比值规律的影响,并对规范对其规定的适用性提出建议。研究结果表明:场地越硬,峰值加速度越大,且随着场地变软,峰值加速度比值减小速率加快;随着震中距增加,各类场地上峰值加速度比值呈减小趋势,且场地越软,减小趋势越明显;震级对峰值加速度比值无显著规律性的影响。在对峰值加速度比值统计过程中,各条件下比值均值大致符合《建筑抗震设计规范》(GB50011-2010)中的规定,但是也有相当一部分比值甚至已经大于1,目前规范中对此取值2/3的规定可能造成安全隐患。

Based on the selected 849 three-component strong motion records from the Western United States and China Taiwan Chi-Chi earthquake,we calculated the ratio of the vertical and horizontal peak ground acceleration V/H,and discussed the effect of site category,epicentral distance and magnitude on V/H,and give some suggestions on applicability of the code on it.The results indicate that the peak acceleration increases with the hardening of site,and decreases significantly with its softening.With epicentral distance increasing,the peak ground acceleration on all sites shows a decreasing tendency,and the softer the site is,the evident the decreasing tendency becomes.The peak acceleration ratio has no regular change when the magnitude increases.In the statistics of peak acceleration,it is found that the mean value of the ratio conforms roughly with the provisions of the code,but a part of the ratio is even greater than 1,and so the ratio of 2/3 of the current rules may cause potential danger.