RED-ACT: 11月29日日本本州5.5级地震破坏力分析

RED-ACT Report

Real-time Earthquake Damage Assessment using City-scale Time-history analysis

Nov. 29, M5.5 Japan Sanriku Oki Earthquake

Research group of Xinzheng Lu at Tsinghua University (luxz@tsinghua.edu.cn)

First reported at 13:40, Nov. 29, 2019 (Beijing Time, UTC +8)

Acknowledgments and Disclaimer

The authors are grateful for the data provided by K-NET and KiK-net. This analysis is for research only. The actual damage resulting from the earthquake should be determined according to the site investigation.

Scientific background of this report can be found at: http://www.luxinzheng.net/rr.htm

1. Introduction to the earthquake event

At 13:01 29 Nov 2019 (Local Time, UTC +9), an M 5.5 (JMA) earthquake occurred in Japan Sanriku Oki. The epicenter was located at 143.1 39.1, with a depth of 10.0 km. 

2. Recorded ground motions

10 ground motions near to epicenter of this earthquake were analyzed. The names and locations of the stations can be found Table 1. The maximal recorded peak ground acceleration (PGA) is 14.8 cm/s/s. The waveform and corresponding response spectra in comparison with the design spectra specified in the Chinese Code for Seismic Design of Buildings are shown in Figure 1.

Figure 1 Waveform and response spectra of the recorded ground motions with maximal PGA

3. Damage analysis of the target region subjected to the recorded ground motions

Using the real-time ground motions obtained from the strong motion networks and the city-scale nonlinear time-history analysis, the damage ratios of buildings located in different places can be obtained. The building damage distribution and the human feeling distribution near to different stations are shown in Figure 2 and Figure 3, respectively. These outcomes can provide a reference for post-earthquake rescue work

Figure 2 Damage ratio distribution of the buildings near to different stations

Figure 3 Human feeling distribution near to different stations

4. Earthquake-induced landslide of the target region subjected to the recorded ground motions

According to local topographic data, lithology data and ground motion records, the distribution of earthquake-induced landslide near to different stations under the different proportions of the landslide slab thickness that is saturated can be calculated, as shown in Figure 4. The basemap shows the distribution of the local slope. The number in the circle represents the critical slope of the landslide. The earthquake-induced landslide tends to occur with a higher probability when the slope is larger than this threshold value.

(a)The proportion of the landslide slab thickness that is saturated equals 0%

 (b)The proportion of the landslide slab thickness that is saturated equals 50%

(c)The proportion of the landslide slab thickness that is saturated equals 90%

Figure 4 Distribution of earthquake-induced landslide near to different stations

Scientific background of this report can be found at: http://www.luxinzheng.net/rr.htm

Table 1 Names and locations of the strong motion stations

No.Station NameLongitudeLatitude

1 IWT004 141.967 39.7357

2 IWT006 141.975 39.485

3 IWT007 141.856 39.2701

4 IWT012 141.138 39.3209

5 IWT013 141.564 39.3291

6 IWT020 141.329 39.7841

7 IWT021 141.082 39.9203

8 MYG001 141.568 38.9015

9 MYG002 141.511 38.7262

10 MYG006 140.977 38.566