TY - JOUR
T1 - Simulation of spatially varying seafloor motions using onshore earthquake recordings
AU - Li, Chao
AU - Li, Hong Nan
AU - Hao, Hong
AU - Bi, Kai Ming
N1 - Funding Information:
The authors would like to acknowledge the financial support from the National Key R&D Program of China (2016YFC0701108) and the Australian Research Council Discovery Early Career Researcher Award (DE150100195). The onshore and offshore earthquake recordings provided by the US National Center for Engineering Strong Motion Data on their website are gratefully acknowledged. In addition, the authors are greatly indebted to the anonymous reviewers for their valuable suggestions and comments.
Publisher Copyright:
© 2018 American Society of Civil Engineers.
PY - 2018/9/1
Y1 - 2018/9/1
N2 - Compared to the seismic motions recorded on the onshore sites, the quantity of offshore earthquake recordings is very limited. This paper presents a novel method to simulate spatially varying ground motions at multiple seafloor sites by using the more abundant onshore earthquake records. A pair of onshore and offshore seismic motions recorded in the same earthquake event is selected, and the onshore recording is employed as the predefined motion to simulate offshore seismic motions. The detailed information of the onshore and offshore sites beneath respective stations is collected, and the ground motion transfer functions are computed by including the effects of seawater and soil saturation on the seismic P wave propagation. Using the power spectral density (PSD) functions of the onshore recording and the onshore and offshore site transfer functions, the ground motion PSD functions on the offshore site are estimated, and the threecomponent seafloor seismic motions are synthesized. The basic characteristics of the synthesized seafloor motions are compared with the seafloor recording, and the feasibility of the proposed method is validated. Finally, the approach is further extended to the simulation of spatially varying seafloor motions by considering the spatial variation between the seafloor motions at various offshore sites. The effect of local offshore site on the lagged coherency of spatial seafloor motions is also investigated.
AB - Compared to the seismic motions recorded on the onshore sites, the quantity of offshore earthquake recordings is very limited. This paper presents a novel method to simulate spatially varying ground motions at multiple seafloor sites by using the more abundant onshore earthquake records. A pair of onshore and offshore seismic motions recorded in the same earthquake event is selected, and the onshore recording is employed as the predefined motion to simulate offshore seismic motions. The detailed information of the onshore and offshore sites beneath respective stations is collected, and the ground motion transfer functions are computed by including the effects of seawater and soil saturation on the seismic P wave propagation. Using the power spectral density (PSD) functions of the onshore recording and the onshore and offshore site transfer functions, the ground motion PSD functions on the offshore site are estimated, and the threecomponent seafloor seismic motions are synthesized. The basic characteristics of the synthesized seafloor motions are compared with the seafloor recording, and the feasibility of the proposed method is validated. Finally, the approach is further extended to the simulation of spatially varying seafloor motions by considering the spatial variation between the seafloor motions at various offshore sites. The effect of local offshore site on the lagged coherency of spatial seafloor motions is also investigated.
KW - Coherency loss function
KW - Onshore earthquake recording
KW - Power spectral density function
KW - Seafloor seismic motion
KW - Transfer function
UR - http://www.scopus.com/inward/record.url?scp=85049338048&partnerID=8YFLogxK
U2 - 10.1061/(ASCE)EM.1943-7889.0001507
DO - 10.1061/(ASCE)EM.1943-7889.0001507
M3 - Journal article
AN - SCOPUS:85049338048
SN - 0733-9399
VL - 144
JO - Journal of Engineering Mechanics
JF - Journal of Engineering Mechanics
IS - 9
M1 - 04018085
ER -