Derivation of ground motion attenuation relation for earthquake in the South China Sea areas based on a hybrid method
Hu Jinjun1,2 Zheng Xu1,2 Xie Lili1,2
1. Institute of Engineering Mechanics, China Earthquake Administration, Harbin 150080, China;
2. Key Laboratory of Earthquake Engineering and Engineering Vibration, China Earthquake Administration, Harbin150080, China
Abstract：The South China Sea is located close to the subduction zone, and the engineering characteristics of subduction zone earthquakes is the basis of sea area seismic research. In order to supply reasonable ground motions for hazard analysis of offshore engineering, for the South China Sea without actual seismic data available, a method of establishing the local attenuation relationship was proposed based on the numerical simulations and the empirical attenuation relationships from other regions. In this method, the stochastic finite fault method was employed to simulate the ground motions of intraplate earthquakes for subduction zones of the South China Sea and the northeastern Japan. Based on these simulated ground motions of different magnitudes and epicentral distances, the ground motion attenuation relationships for these subduction zones were regressed. Hence, the quantitative relationship of the two subduction zones were obtained, and based on the quantitative relationship and the empirical attenuation relationship of Japan subduction zone, the earthquake attenuation relationship of intraplate earthquakes for the subduction zones of the South China Sea was eventually established. By comparing the attenuation relationship proposed in this work with those for Japan and Wenchuan earthquake, it is found that: the attenuation characteristics of different earthquakes have regional differences; the ground motion attenuation rate of the intraplate earthquakes for the subduction zones of sea is faster than that of the shallow crustal case such as the Wenchuan earthquake; the attenuation relationship for intraplate earthquake of the subduction zones established by the hybrid method of numerical simulation and empirical attenuation relationship, shall be applicable and can be referred by those regions without actual ground motions. Therefore, the established earthquake attenuation relationships can be referred by marine and offshore engineerings.
胡进军 郑旭 谢礼立. 基于混合方法的南海海域地震动衰减关系研究[J]. 土木工程学报, 2018, 51(7): 36-49.
Hu Jinjun Zheng Xu Xie Lili. Derivation of ground motion attenuation relation for earthquake in the South China Sea areas based on a hybrid method. 土木工程学报, 2018, 51(7): 36-49.
