Estimation of Ground Profiles Based on Microtremor Survey in the Bangkok Basin

Frontiers in Built Environment

Teraphan Ornthammarath¹  Panon Latcharote¹  Takafumi Kitaoka²  Aiko Furukawa³  Bidhya Subedi³  Junji Kiyono³  Bhuddarak Charatpangoon⁴  Yusuke Ono⁵ 

[1]Department of Civil and Environmental Engineering, Faculty of Engineering, Mahidol University, Salaya, Thailand

[2]Department of Civil, Faculty of Environmental and Urban Engineering, Environmental and Applied Systems Engineering, Kansai University, Suita, Japan

[3]Department of Urban Management, Graduate School of Engineering, Kyoto University, Kyoto, Japan

[4]Faculty of Engineering, Center of Excellence in Natural Disaster Management, Chiang Mai University, Chiang Mai, Thailand

[5]Faculty of Engineering, Social Systems and Civil Engineering, Tottori University, Tottori, Japan

关键词: microtremor survey;    Bangkok basin;    HVSR;    SPAC method;    long-period ground motions;    CCA method;    shear-wave velocity profile;   

DOI  :  10.3389/fbuil.2021.651902

来源: Frontiers

【 摘 要 】

Multiple earthquakes have been felt in high-rise buildings in Bangkok despite the epicenters being far away. Seismic wave recordings in the Bangkok basin show a low-frequency peak. This study uses horizontal-to-vertical spectral ratio (HVSR) analysis and array analysis of ambient vibration data to find the predominant period of the ground and the shear wave velocity profiles at five sites in Bangkok. The accuracy of the accelerometer used for the ambient data recording was verified by comparing results with velocity-meter results. The estimated predominant period was within 0.68–0.86 s. From the array records, dispersion curves of the Rayleigh-wave phase velocity were extracted and inverted for the deep layers. The results show that the shear-wave velocity of the top clay layer is low (82–120 m/s) at depths of 11–14.3 m. The low-frequency peak in the HVSR of the earthquake data, and the sediment layer with low shear-wave velocity implies that Bangkok is at risk of amplification of long-period earthquake waves.

【 授权许可】

CC BY