Title:
Geotechnical Preliminary Report of The Mj 7.3 Fukushima Earthquake on March 16, 2022

Authour:
Masataka SHIGA¹, Kwok-Kwan LAU², Pei-chen HSIEH³, and Takashi KIYOTA⁴

¹ Member of JSCE, Assistant Professor, Institute of Industrial Science, The University of Tokyo
² Ph.D. student, Dept. of Civil Eng., Graduate School of Eng., The University of Tokyo
³ Member of JSCE, Ph.D. student, Dept. of Civil Eng., Graduate School of Eng., The University of Tokyo
⁴ Member of JSCE, Associate Professor, Institute of Industrial Science, The University of Tokyo

Key Facts

• Hazard Type: Earthquake
• Date of the disaster: March 16th, 2022
• Location of the survey: Fukushima Prefecture and Miyagi Prefecture
• Date of the field survey: March 21st and 22nd, 2022
• Survey tools: Photos, videos, UAV, and LiDAR

Key findings:

1.  Cracking, ground settlement, and ground deformation were observed in the roads, bridge approaches, and embankments in Fukushima Prefecture and Miyagi Prefecture
2.  The landslides in Date Dam, Unoomisaki Tunnel portal area, and Tarumizu Dam could be associated with the strong ground motion of this earthquake event.
3.  Liquefaction was also identified in Soma Port of Fukushima Prefecture.

Key Words: The 2022 Earthquake off the coast of Fukushima Prefecture, Ground Damage, Slope Failure, Liquefaction

Paper: PDF 7,824KB

Title:
Widespread ground deformation over the Palu Basin caused by the 2018 Sulawesi, Indonesia Earthquake

Authour:
Kazuo KONAGAI¹, Ryoichi FURUTA², Takashi KIYOTA³

¹Fellow of JSCE, Professor Emeritus, University of Tokyo
² Member of JSCE, Group Leader, Social Infrastructure Group, Remote Sensing Technology Center of Japan
³Member of JSCE, Associate Professor, Institute of Industrial Science, University of Tokyo

Key Facts

• Hazard Type: Earthquake
• Date of disaster: Sept. 28th, 2018
• Location of Survey: Palu, Central Sulawesi, Indonesia
• Date of the field survey: Not Applicable
• Survey tools: Digital Terrain Models, InSAR

Key findings:

1. Pre and Post-earthquake Digital Terrain Models (DTMs) covering Palu Basin suggested that the entire stretch of the basin, mainly west of the irrigation canal, seemed to have deformed, not to mention the large flow slide sites.
2. Line-of-sight (LOS) deformations over the Palu Basin obtained from ALOS 2/PALSAR 2 at two different days after the earthquake (October 12, 2018, and January 4, 2019) showed that the flat land has slowly and steadily been deforming over the three months.

Key Words: 2018 Sulawesi Earthquake, long-lasting ground displacement buildup, lateral slides

Paper: PDF 1,900KB

Title:
RECONNAISSANCE REPORT ON THE EARTHQUAKE IN OSAKA-FU HOKUBU ON JUNE 18, 2018

Authour:
Junji KIYONO¹, Yoshikazu TAKAHASHI², Tetsuo TOBITA³, Yasuko KUWATA⁴, Hiroyuki GOTO⁵ and  Yoshihiro OKUMURA⁶

¹Member of JSCE, Professor, Dept. of Urban Management, Grad. School of Eng., Kyoto University
²Member of JSCE, Professor, Dept. of Civil and Earth Resources Eng., Grad. School of Eng., Kyoto University
³Member of JSCE, Professor, Dept. of Environmental and Urb. Eng., Grad. School of Sci. and Eng., Kansai University 
⁴Member of JSCE, Assoc. Professor, Dept. of Civil Eng., Grad. School of Eng., Kobe University
⁵Member of JSCE, Assoc. Professor, Research Division of Earthquake Disaster, Disaster Prevention Research Institute, Kyoto University
⁶Member of JSCE, Assoc. Professor, Dept. of Safety Management., Grad. School of Societal Safety Science, Kansai University

Key Facts
・Hazard Type: Earthquake
・Date of the disaster: 18 June 2018
・Location of the survey: Takatsuki City, Ibaraki City, Suita City, Osaka City
・Date of the field survey: June 2018
・Survey tools: Digital camera, GPS, Laser Rangefinder, Tape measure

Key findings:
1) Strong shaking of JMA seismic intensity 6− was observed, however, there was not destructive damage to buildings and infrastructures.
2) Pulse-like ground motions were recorded near the source fault, Takatsuki and Ibaraki cities.
3) Damage due to liquefaction was minor as observed in both the field investigation and numerical analysis with the recorded motion.
4) This earthquake was a moderate earthquake, but the supply of water and gas was stopped over a wide range.
5) Osaka monorail required time to completely recover because of failure of the monorail switches to move the complicated monorail lines.
6) Three people were killed by falling furniture or objects, and two people by collapse of block walls.

Key Words: earthquake in Osaka–fu Hokubu on 18 June 2018, reconnaissance report, earthquake ground motion, source effect, lifeline damage, civil life

Paper: PDF 5,695KB

Title:
Preliminary Report of the Damage by the 2021 Off Fukushima Prefecture Earthquake Mj7.3, Japan

Authour:
Kazuma INOUE¹, Takashi KIYOTA², Masataka SHIGA³, Ji Dang⁴ and Xin Wang⁵

¹Member of JSCE, Lecturer, Dept. of Civil Eng., National Institute of Technology, Gunma College
²Member of JSCE, Associate Professor, Institute of Industrial Science, The University of Tokyo
³Member of JSCE, Assistant Professor, Institute of Industrial Science, The University of Tokyo
⁴Member of JSCE, Associate Professor, Department of Civil and EnviromentalEngineering, Saitama University
⁵Associate Professor, Department of Architecture, Ashikaga University

Key Facts
・Hazard Type : Earthquake
・Date of the disaster : February 13th, 2021
・Location of the survey : Fukushima and Miyagi prefectures, Japan
・Date of the field survey : February 15th and 16th, 2021
・Survey tools : Digital Camera

Key findings:
1) Minor damage due to soil liquefaction and ground deformation were found in Yamamoto Townand Soma Port.
2) Damage, such as road pavement cracks, cracks around abutment and suspected liquefication inSoma Overpass Bridge and Soma East Bridge are reported.
3) Cracks and spalling due to shear deformation in horizontal beams of the frame piers of theShinkansen viaduct near to Shiroishi Zao station were found.
4) Damage to buildings was not severe compared to the measured strong ground motions.

Key Words : Offshore the Fukushima Prefecture Earthquake, Geotechnical damage,Damage to bridges, Damage to builidings・Hazard Type: Earthquake

Paper: PDF 2,556KB