A seismic intensity estimation method based on the fuzzy-norm theory

作者：Wang Qian^*; Fu Jihua; Wang Zhongyu; Tong Jie

来源：Soil Dynamics and Earthquake Engineering, 2012, 40: 109-117.

DOI：10.1016/j.soildyn.2012.03.010

The seismic intensity is one of the important factors to describe one earthquake's damage. After an earthquake, according to the distribution of its seismic intensity, the government can perform the emergency rescue response and alleviate the damage in time. In general, the relationships between the ground motion parameters (peak ground acceleration, velocity mostly used, and some others) and the seismic intensity are set up to estimate the seismic intensity. Unfortunately the empirical relationships based on the regression analysis are derived from large amounts of data and have some regional limits. There is little information available under small sample condition. Besides, the accuracy and the regional differences also limit the applications of the regression relationships. Recently some researches show that the Housner intensity has higher correlation with the seismic intensity than some other ground motion parameters. This paper proposes a fuzzy-norm method to establish the relationships between seismic intensity and Housner intensity. The fuzzy-norm method uses fuzzy subordinate functions and the infinite norm to get the Housner intensity interval under a certain seismic intensity. The seismic intensity can be estimated by the Housner intensity intervals. The number of the sample data can be at least six. Because the fuzzy-norm is not based on the law of large numbers and central limit theorem, the fuzzy-norm method allows a small sample and has high calculation speed. In addition, site correction based on the site predominant periods (frequency) is applied to modify the Housner intensity. Through experiments of two data sets. Western-China and Taiwan Chi-Chi earthquakes, the estimation accuracy of the seismic intensity can reach about 60% by usage of the modified Housner intensity. Compared with the previous studies, the proposed model enables the governments to make more reliable decisions where the earthquake stations are sparse and the records are inadequate.

• 出版日期2012-9
• 单位北京航空航天大学; 中国地震局