三维地震动强度非平稳特性研究及建模

发布时间：2018-03-21 08:10

本文选题：KiK-net数据库　切入点：强度非平稳特性　出处：《南京工业大学》2015年硕士论文　论文类型：学位论文

【摘要】：地震动强度非平稳特性对结构的地震反应有重要影响,准确描述地震动强度非平稳特性对结构抗震分析具有重要意义。本文从地震动固有特性出发,通过统计分析建立了强度非平稳模型,并根据地震动的工程特征给出了具有平均意义和概率统计意义的模型参数取值,最后依据所得参数值生成了具有完全非平稳特性且拟合目标反应谱的人工地震波。本文主要内容包括：1.强震记录收集与整理。从日本KiK-net强震数据库的大量三维强震记录中,选择了具有明显强度非平稳特性且场地类别资料完整的原始地震波共20850条,经基线修正后将其按照震级、震中距、场地类别进行了分组。2.建立三维地震动强度非平稳模型。以模型累积能量与记录累积能量的最佳逼近为目标,使用遗传算法识别出了20850组模型参数。对所有参数进行概率分布拟合给出了具有统计意义的模型参数取值；结合所有参数的相关性分析结果和衰减关系回归分析结果给出了具有平均意义的模型参数取值。经验证本文模型具有较好的准确性与适用性。3.三维地震动幅值特性研究。统计了3475组三维地震波的峰值加速度,发现水平方向地震波较小峰值加速度与较大峰值加速度的比值符合极值分布,均值分别为0.80(土层)和0.76(基岩)；竖向地震波峰值加速度与水平方向较大地震波峰值加速度的比值符合广义极值分布,均值分别为0.50(土层)和0.54(基岩)。4.完全非平稳人工波模拟。将初始反应谱与目标反应谱间的差距表达为差异谱,使用随机谱表现法生成了若干条完全非平稳人工地震波,其平均反应谱与目标反应谱相拟合,其完全非平稳特性接近天然地震波。本文提出的地震动强度非平稳模型及其参数取值可以描述特定条件的地震动强度非平稳特性,模型参数的统计分布规律可为随机分析方法提供具有随机强度非平稳特性的地震输入,另外本模型也可以为生成完全非平稳的地震波提供理论基础。
[Abstract]:The non-stationary characteristics of ground motion intensity have an important influence on the seismic response of structures. It is important to describe accurately the non-stationary characteristics of ground motion intensity for the seismic analysis of structures. Based on the statistical analysis, the non-stationary model of intensity is established, and the model parameters with average meaning and probability statistical significance are given according to the engineering characteristics of the ground motion. Finally, artificial seismic waves with completely non-stationary characteristics and fitting target response spectra are generated according to the obtained parameters. The main contents of this paper include: 1. Collection and collation of strong earthquake records. From a large number of 3-D strong earthquake records in the KiK-net strong earthquake database in Japan, the main contents of this paper are as follows: 1. A total of 20850 original seismic waves with obvious intensity non-stationary characteristics and complete site classification data were selected, which were revised according to magnitude and epicentral distance after baseline correction. The classification of the site is divided into groups. 2. A three-dimensional nonstationary model of ground motion intensity is established. The goal is to obtain the best approximation between the accumulated energy of the model and the recorded accumulated energy. 20850 groups of model parameters are identified by genetic algorithm, and the model parameters with statistical significance are obtained by probability distribution fitting of all the parameters. Combined with the results of correlation analysis of all parameters and regression analysis of attenuation relation, the average values of model parameters are given. It is proved that the model in this paper has good accuracy and applicability. 3. The peak acceleration of 3475 groups of 3-D seismic waves was calculated. It is found that the ratio of the smaller peak acceleration to the larger peak acceleration of the horizontal seismic wave accords with the extreme value distribution. The mean values are 0.80 (soil layer) and 0.76 (bedrock), respectively, and the ratio of peak acceleration of vertical seismic wave to that of larger seismic wave in horizontal direction is consistent with the generalized extreme value distribution. The mean values are 0.50 (soil layer) and 0.54 (bedrock) respectively. The completely non-stationary artificial wave is simulated. The difference between the initial response spectrum and the target response spectrum is expressed as the difference spectrum, and some completely non-stationary artificial seismic waves are generated by the stochastic spectral representation method. The mean response spectrum is fitted to the target response spectrum, and its completely non-stationary characteristic is close to that of natural seismic waves. The proposed non-stationary model of ground motion intensity and its parameter values can describe the non-stationary characteristics of ground motion intensity under certain conditions. The statistical distribution law of the model parameters can provide the earthquake input with random intensity and non-stationary characteristics for the stochastic analysis method. In addition, the model can also provide a theoretical basis for generating completely non-stationary seismic waves.
【学位授予单位】：南京工业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：P315.9

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