基于实际记录和震源参数不确定性的较高概率高频地震动研究

地震灾害损失主是由地震动造成的建筑物破坏、倒塌导致的，而我国大部分民用建筑受高频地震动影响较大，真实准确的高频地震动对于建筑物抗震设计及震害模拟意义重大。因此在评估高频地震动时，考虑震源参数的多种不确定性因素，获得合理可靠且更加符合实际情况的近场高频地震动尤为重要。本项目拟以芦山地震影响区为示范区，依托芦山地震丰富的强震数据和科考成果，采用经验格林函数法作为模拟工具，用逻辑树方法和统计学经验关系综合处理参数的多种不确定性，同时将非均匀应力降和动力学拐角频率引入到关键震源参数中。通过建立考虑参数不确定性的滑动分布特征震源模型，评估不同设定震级的概率较高的高频强地震动，并尝试给出可量化的验证地震动评估结果可靠性的方案。发展基于真实小震记录和参数不确定性的实用型的高频地震动评估方法，为建筑物抗震设计及震害模拟提供更加真实可靠的高频地震动输入。

The loss of earthquake disaster is mainly caused by the damage and collapse of buildings caused by ground motion, and most of civil buildings in our country are greatly affected by high-frequency ground motion. The real and accurate high-frequency ground motion is of great significance for building seismic design and earthquake damage simulation. Therefore, when evaluating the high frequency ground motion, it is particularly important to consider a variety of uncertain factors of source parameters to obtain reasonable and reliable near-field high frequency seismic motion which is more in line with the actual situation. Based on the abundant strong earthquake data and scientific research results of the Lushan earthquake, this project plans to take the Lushan earthquake affected area as the demonstration area, use the empirical Green's function method as the simulation tool. The logic tree method and statistical empirical relationship are used to comprehensively deal with various uncertainties of parameters. The non-uniform stress drop and dynamic corner frequency are introduced into the key source parameters. By establishing the sliding distribution characteristic source model considering the parameter uncertainty, the high frequency strong ground motions with higher probability of different set magnitudes are obtained. The quantifiable scheme to verify the reliability of ground motion evaluation results is tried to be given. The practical high frequency ground motion evaluation method based on real small earthquake records and parameter uncertainty is also developed. It can provide more real and reliable high frequency ground motion input for seismic design and damage simulation of buildings.