Local site conditions play an important role in the effective application of strong motion recordings.In the China National Strong Motion Observation Network System（NSMONS）,some of the stations do not provide boreho...Local site conditions play an important role in the effective application of strong motion recordings.In the China National Strong Motion Observation Network System（NSMONS）,some of the stations do not provide borehole information,and correspondingly,do not assign the site classes yet.In this paper,site classification methodologies for free-field strong motion stations are reviewed and the limitations and uncertainties of the horizontal-to-vertical spectral ratio（HVSR） methods are discussed.Then,a new method for site classification based on the entropy weight theory is proposed.The proposed method avoids the head or tail joggle phenomenon by providing the objective and subjective weights.The method was applied to aftershock recordings from the 2008 Wenchuan earthquake,and 54 free-field NSMONS stations were selected for site classification and the mean HVSRs were calculated.The results show that the improved HVSR method proposed in this paper has a higher success rate and could be adopted in NSMONS.展开更多
Because of the confining compression of the Pacific, Eurasian and Indian plates, the Chinese mainland is frequently stricken with earthquakes, especially in the Qinghai Tibet Plateau and surrounding areas and along th...Because of the confining compression of the Pacific, Eurasian and Indian plates, the Chinese mainland is frequently stricken with earthquakes, especially in the Qinghai Tibet Plateau and surrounding areas and along the NS-trending tectonic zone from Yinchuan to Lanzhou, Chengdu, and finally to the Kunming tectonic belt （Fig. 1）. Historical records show that there are 14 earthquakes of 〉Ms 8 occurring in the two regions, eight of which occurred along the latter tectonic belt. The 2008 Wenchuan earthquake located on both the NS tectonic zone and the Longmenshan fault zone along the eastern margin of the Qinghai-Tibet Plateau.展开更多
基金National Key Technology R&D Program Under Grant No.2009BAK55B05Nonprofit Industry Research Project of CEA Under Grant No.201108003Science Foundation of Institute of Engineering Mechanics,CEA Under Grant No.2010C01
文摘Local site conditions play an important role in the effective application of strong motion recordings.In the China National Strong Motion Observation Network System（NSMONS）,some of the stations do not provide borehole information,and correspondingly,do not assign the site classes yet.In this paper,site classification methodologies for free-field strong motion stations are reviewed and the limitations and uncertainties of the horizontal-to-vertical spectral ratio（HVSR） methods are discussed.Then,a new method for site classification based on the entropy weight theory is proposed.The proposed method avoids the head or tail joggle phenomenon by providing the objective and subjective weights.The method was applied to aftershock recordings from the 2008 Wenchuan earthquake,and 54 free-field NSMONS stations were selected for site classification and the mean HVSRs were calculated.The results show that the improved HVSR method proposed in this paper has a higher success rate and could be adopted in NSMONS.
文摘Because of the confining compression of the Pacific, Eurasian and Indian plates, the Chinese mainland is frequently stricken with earthquakes, especially in the Qinghai Tibet Plateau and surrounding areas and along the NS-trending tectonic zone from Yinchuan to Lanzhou, Chengdu, and finally to the Kunming tectonic belt （Fig. 1）. Historical records show that there are 14 earthquakes of 〉Ms 8 occurring in the two regions, eight of which occurred along the latter tectonic belt. The 2008 Wenchuan earthquake located on both the NS tectonic zone and the Longmenshan fault zone along the eastern margin of the Qinghai-Tibet Plateau.
