基于地震动参数的烈度评定标准对比研究∗——以岷县-漳县6.6级地震为例

A Comparative Study on Seismic Intensity Evaluation Standards Based on Ground Motion Parameters: a Case Study of the Minxian Zhangxian Ms6.6 Earthquake

摘要:

地震动参数是评定地震时地震烈度的参考依据，是烈度表的重要组成部分，尤其是在缺乏某些地震灾害判别现象的地区，地震动参数就成为非常有效的判别标准之一。对岷漳地震震区及周边获取的地震动记录进行处理和计算分析，得到水平向、三分向合成地震动参数和地震仪器烈度值；分别开展基于水平向地震动参数、三分向合成地震动参数和地震仪器烈度的烈度评定；探讨三种烈度评定方法对烈度评定结果的影响规律，从地震动参数定量参考指标角度验证现行地震烈度表与原有烈度表的一致性与差异性。结果表明：基于三分向合成地震动参数和地震仪器烈度的评定过程更为规范，结果更加具体和准确；基于三分向合成地震动参数和地震仪器烈度的烈度评定结果与实际宏观地震烈度符合良好，相差±1 度以内的占比55%，相差±2 度以内的占比91%，完全吻合率较之水平向地震动参数的烈度评定结果提高了18%。研究对于更加客观和科学地评定地震烈度具有重要意义和实用价值。

Abstract:

With the accumulation of earthquake damage experience, the deepening understanding ofearthquakes, and the development of seismic observation instruments, researchers have persistentlypursued the continuous modification of intensity standards to make intensity evaluations more objec-tive and scientific. Ground motion parameters serve as a reference basis for assessing the seismic inten-sity of an earthquake and are an important component of seismic intensity scales. They are particularlyeffective in regions lacking certain seismic disaster discrimination phenomena. This paper processedand analyzed ground motion records obtained from the Minxian-Zhangxian Earthquake region and itssurroundings to obtain horizontal, three-component synthetic ground motion parameters and seismicinstrument intensity values. They study conducted seismic intensity evaluations based on horizontalground motion parameters, three-component synthetic ground motion parameters, and seismic instru-ment intensity. It explored the influence of the three intensity evaluation methods on the results, veri-fying the consistency and differences between the current seismic intensity scale and the original inten-sity scale from the perspective of quantitative reference indicators of ground motion parameters. Theresults showed that: (1) The evaluation process based on three-component synthetic ground motion pa-rameters and seismic instrument intensity was more standardized, with results being more specific andaccurate. (2) The intensity evaluation results based on three-component synthetic ground motion pa-rameters and seismic instrument intensity closely matched the actual macroseismic intensity, with55% of the evaluations differing by ±1 degree and 91% differing by ±2 degrees. (3) The completematch rate improved by 18% compared to the intensity evaluation results based on horizontal groundmotion parameters. This research holds significant importance and practical value for more objectiveand scientific seismic intensity evaluations.