Preliminary Information on the 2003 Tokachi-oki Earthquake Yohsuke Kawamata and Professor Scott Ashford Department of Structural Engineering University of California, San Diego
References for Slides 1, 3 : http://earthquake.usgs.gov/ USGS 2, 4 : http://www.k-net.bosai.go.jp/k-net/ Khoshin Network, K-Net, National Research Institute for Earth Science and Disaster Prevention, Japan http://www.hkd.mlit.go.jp/ Hokkaido Regional Development Bureau for background information. Acknowledgement We are indebted to Dr. Sugano, head of Structural Dynamics Division in Port and Airport Research Institute (PARI), Japan, and Dr. Kohama, researcher of Structural Dynamics Division in PARI for some pictures and data. We would like to express sincere gratitude to them. Web-site of PARI, Japan : http://www.pari.go.jp/
Tokachi-oki oki Earthquake, 2003 1 port Basic Information Time (in JAPAN) : 4:50a.m. Sep. 26/2003 Location of epicenter : Latitude 41.827N Longitude 143.830E Depth of focus : 33km Magnitude : 8.3
Peak Acceleration in each Region 2 Peak Acceleration (Gal) 2000 1000 500 200 100 50 20 10 5 2 1 0.5 0.2
The second largest Earthquake 3 port Basic Information Time (in JAPAN) : 6:08a.m. Sep. 26/2003 Location of epicenter : Latitude 41.831N Longitude 143.496E Depth of focus : 33km Magnitude : 7.4
Peak Acceleration in each Region 4 Peak Acceleration (Gal) 2000 1000 500 200 100 50 20 10 5 2 1 0.5 0.2
Mechanism of Tokachi-oki oki Earthquake, 2003 5 Focus Plate (Land-side) Trench Sea The Pacific Plate
The Damage of Sewerage Structures 6 Toyokoro Trace of Sand Boiling near Lifted-up Manhole Lifted-up Manhole
The Damage of Sewerage Structures 7 Kushiro (town) Lifted-up Manhole and gushed Soil during Liquefaction Lifted-up Manhole
The Damage of Sewerage Structures 8 Place where Lift-up of Manhole is observed Kushiro Kushiro (dozens, 30-100cm) Urakawa Akan (4) Ombetsu (25) Taiki Hamanaka (several, about 20cm) Toyokoro (30, max90cm) Kushiro(town (town) (dozens, max about 200cm) (the number, height of lift-up)
The Damage of Sewerage Structures 9 Failure Mode Sand Boiling (notice : this is only concept) Sand Boiling Crack or Residual Strain Rigid Pipe Manhole Flexible Pipe Residual Strain Original Soil (Liquefied) Lift-up Force Replaced Soil (Liquefied)
The Damage of Embankment Structures 10 Toyokoro Collapsed Embankment
The Damage of Embankment Structures Collapsed Embankment 11 Liquefied Soil Liquefied Soil Toyokoro
The Damage of Embankment Structures 12 Place where Embankment was collapsed Lateral Spread was observed Under investigation ( ) : the number of collapsed points Abashiri River (1) Tokachi River Kushiro River (5) Shibetsu River (6) Kiyomappu River (2) Tokachi River (66)
The Damage of Embankment Structures 13 Failure Mode (notice : this is only concept) Settlement Embankment Land Slide Lateral Spread Liquefied Stratum
The Damage of Port Structures (at Kushiro Port) 14 Kushiro Settlement behind Quay Wall Crack
The Damage of Port Structures (at Kushiro Port) 15 Kushiro Trace of Sand Boiling Settlement behind Quay Wall
The Damage of Port Structures (at Tokachi Port) 16 Tokachi Settlement around Terminal Building Sand Boiling
The Damage of Port Structures (at small Fishing Port) 17 Taiki Face Line of Quay Wall moved to sea-side side
The Damage of Port Structures Port where Liquefaction was observed (excluding small fishing port) 18 Shiraoi Port Nemuro Port Kushiro Port Kiritappu Port Tomakomai Port Tokachi Port Tokachi Port
The Damage of Port Structures 19 Failure Mode (notice : this is only concept) Settlement Crack Sand Boiling Displacement Caisson Back-filled Gravel Reclaimed Soil (Liquefied) Mound (Gravel)
The Damage of Bridge Structures 20 Tokachi-kako kako Bridge Toyokoro
Introduction of other Web-sites on Tokachi-oki oki Earthquake 21 Japan Meteorological Agency : http://www.jma.go.jp/ Hokkaido Government : http://www.pref.hokkaido.jp/ The Hokkaido Shimbun Press : http://www.hokkaido-np.co.jp/ The Headquarters for Earthquake Research Promotion : http://www.jishin.go.jp/main/index.html