FIELD RECONNAISSANCE OF THE 2004 NIIGATA-KEN CHUETSU
EARTHQUAKE
Prepared by J.P. Bardet on November 5, 2004
As part of the EERI-GEER reconnaissance of the 2004 Niigata-ken Chuetsu, a reconnaissance team investigated on October 31, 2004, the White Rock Slide, the derailed Shinkansen, the city of Ojiya, and the damaged Shinkansen bridge over the Ueno River. The reconnaissance team was composed of J.P. Bardet, University of Southern California; Hirokazu Iemura, Susumu Iai, Charles Scawthorn, Yoshikazu Takahashi, and Tetsuo Tobita, Kyoto University, Kyoto, Japan; Charles Huyck, ImageCat, Long Beach.
The reconnaissance of the derailed Shinkansen was made possible thanks to special permission obtained from Japanese Railways (JR) by Hirokazu Iemura. The EERI-GEER team expresses their most sincere thanks to Hirokazu Iemura, Susumu Iai, and Tetsuo Tobita for their assistance and contribution to the earthquake reconnaissance.
Figures 1 shows the complete path followed by the reconnaissance team. The complete team started at Sanjo to the North and made their way first to the White Rock Slide and to the derailed Shinkansen. A smaller team, composed of J.P. Bardet, Susumu Iai, and Tetsuo Tobita completed the rest of the reconnaissance. Figure 2 shows the detailed path using a smaller scale (i.e., 2 km). Figures 3, 11, 40, 48 and 57 shows the location of the photographs.
Figure 1. Complete track log of the reconnaissance team on October 31, 2004. The track extends from Sanjo to the North to the damage Shinkansen bridge across the Ueno River to the South.
Figure 2. Detailed track log within the earthquake area.
Figure 3. Location of Figures 4 to 10.
Figure 4. The White Rock slide viewed from across the Shinano River. This rock slide caused several casualties during the earthquake (10/31/2004 9:24:40 AM, N37.33792 E138.82291).
Figure 5. The White Rock slide: the truck and a segment of the asphalt pavement fell into the Shinano River (10/31/2004 9:02:16 AM, N37.33750 E138.82780).
Figure 6. Close view of the White Rock slide (10/31/2004 9:12:40 AM, N37.33760 E138.82773).
Figure 7. Another view of the White Rock slide (10/31/2004 9:04:37 AM, N37.33687 E138.82780).
Figure 8. Close view of the White Rock slide (10/31/2004 9:08:22 AM, N37.33682 E138.82780).
Figure 9. A water treatment plant, which lost its water supply after the earthquake, pumped water from the Shinano River (10/31/2004 9:41:16 AM, N37.35156 E138.82654).
Figure 10. The water treatment plant pumped its temporary water from the Shinano River first into a pond to filter it (10/31/2004 9:41:30 AM, N37.35159 E138.82651).
Figure 11. Location of Figures 12 to 39 in the vicinity of the Shinkansen derailment.
Figure 12. The derailed Shinkansen on its elevated viaduct (10/31/2004 10:01:56 AM, N37.39096 E138.84270).
Figure 13. The Shinkansen bound to Niigata started its derailment 400 m after it emerged from a tunnel. It took 1600 m before it came to stop. (10/31/2004 10:02:06 AM, N37.39096 E138.84270).
Figure 14. One of the possible explanations proposed for the Shinkansen derailment was the large amplitude of the transient viaduct displacement induced by the softening of the liquefied ground (10/31/2004 10:04:42 AM, N37.39094 E138.84270).
Figure 15. The last car of the Shinkansen was leaning on its side (10/31/2004 10:21:12 AM, N37.39063 E138.84570).
Figure 16. The railway track was straight where the Shinkansen started its derailment (10/31/2004 10:21:34 AM, N37.39064 E138.84570).
Figure 17. The continuous rail of the Shinkansen is clamped to steel plate (10/31/2004 10:32:12 AM, N37.39222 E138.84604).
Figure 18. Some of the car were reported to have derailed during aftershocks (10/31/2004 10:32:42 AM, N37.39240 E138.84605).
Figure 19. The yellow chalk mark indicates the position of the wheel before aftershocks. The wheel moved about 10 cm due to aftershocks (10/31/2004 10:34:34 AM, N37.39270 E138.84599).
Figure 20. The left side of the derailed Shinkansen viewed from the front (10/31/2004 10:37:34 AM, N37.39317 E138.84610).
Figure 21. The right side of the derailed Shinkansen viewed from the front (10/31/2004 10:41:24 AM, N37.39310 E138.84604).
Figure 22. The only visible signs of structural damage to the viaduct were the spalling of concrete at a joint between two viaduct segments and the buckling of a pipe. (10/31/2004 11:00:50 AM, N37.38497 E138.84509).
Figure 23. Segment of the rail which was fractured. The rail was cut by JR team for analysis and repair, (10/31/2004 11:04:16 AM, N37.38334 E138.84480).
Figure 24. Another segment of damaged railed (10/31/2004 11:04:52 AM, N37.38326 E138.84488).
Figure 25. An example on the adjacent track of how two segments of the continuous rail are welded and bolted. (10/31/2004 11:05:34 AM, N37.38295 E138.84480).
Figure 26. The base plate is bolted to the viaduct and the rail is clamped onto the base plate. Many clamps failed during the derailment (10/31/2004 11:23:20 AM, N37.37878 E138.84430).
Figure 27. Another view of a failed clamp (10/31/2004 11:23:28 AM, N37.37880 E138.84427).
Figure 28. Permanent settlement of the ground around the pier of the viaduct. There were also a 10 cm gap between the pile and the surrounding soil, which indicates that soil and pile had moved relatively and laterally during the earthquake. (10/31/2004 12:22:26 PM, N37.38647 E138.84528).
Figure 29. Mudline on the viaduct pier indicated that water has squirted from the ground up to 1.6 m in height. (10/31/2004 12:22:45 PM, N37.38652 E138.84521).
Figure 30. Crack in the road running parallel to the Shinkansen viaduct. This road distress was caused by a local failure of the fill under the road; it did not contribute significantly to the response of the Shinkansen viaduct (10/31/2004 12:31:28 PM, N37.38442 E138.84497).
Figure 31. Longitudinal ground crack under the viaduct and gap opening between the viaduct pier and the surrounding soil (10/31/2004 12:40:29 PM, N37.37893 E138.84407).
Figure 32. Another view of the longitudinal ground crack of Figure 31 (10/31/2004 12:40:41 PM, N37.37891 E138.84399).
Figure 33. Another view of the longitudinal ground crack of Figure 31 (10/31/2004 12:40:47 PM, N37.37891 E138.84395).
Figure 34. Settlement of a backfill trench and uplifted manhole, which indicates that the backfill material liquefied during the earthquake. There were no apparent signs of liquefaction in the surrounding native soils. (10/31/2004 12:44:59 PM, N37.37775 E138.84416).
Figure 35. Close view of the manhole raised by liquefaction of the backfill material (10/31/2004 12:46:16 PM, N37.37767 E138.84367).
Figure 36. Another view of the settled backfill trench and ongoing repairs to utilities (10/31/2004 12:46:26 PM, N37.37767 E138.84389).
Figure 37. The height of the Shinkansen viaduct is variable; so is the construction of its segments (10/31/2004 12:48:38 PM, N37.37783 E138.84451).
Figure 38. Local failure of fill material next to the Shinkansen viaduct (10/31/2004 12:56:26 PM, N37.37645 E138.84351).
Figure 39. No apparent damage to an electrical switching station close to the tunnel portal of the Shinkansen (10/31/2004 12:58:36 PM, N37.37698 E138.84192).
Figure 40. Location of Figures 41 to 47.
Figure 41. Slight deformation of railway track of the JR Jo-Etsu line 800 m to the West of the Shinkansen (10/31/2004 1:02:10 PM, N37.36469 E138.83492).
Figure 42. The first floor of the dwelling collapsed during the earthquake (10/31/2004 1:05:26 PM, N37.35568 E138.83060).
Figure 43. Ojiya: The building was red-tagged; it was declared unsafe for entry (10/31/2004 1:42:26 PM, N37.30852 E138.79471).
Figure 44. Ojiya: The shrine was green tagged; safe for entry (10/31/2004 1:43:41 PM, N37.30761 E138.79291).
Figure 45. Ojiya: Temporary supply of water in a refugee camp (10/31/2004 1:47:05 PM, N37.30648 E138.79141).
Figure 46. Ojiya: The strong motion station which recorded a peak acceleration of 1.7 g (10/31/2004 1:56:52 PM, N37.30659 E138.79083).
Figure 47. Ojiya: The strong motion is located in free field next to a rice field (10/31/2004 2:01:44 PM, N37.30640 E138.78984).
Figure 48. Location of Figures 49 to 56.
Figure 49. Echigo Kawaguchi: Buckling of the slab of the tunnel under the railway track at the JR Echigo Kawaguchi railway station (10/31/2004 2:57:59 PM, N37.27287 E138.86171).
Figure 50. Echigo Kawaguchi: Small landslide above the railway station (10/31/2004 3:02:58 PM, N37.27279 E138.86124).
Figure 51. Echigo Kawaguchi: The houses next to the railway station were impacted by the earthquake (10/31/2004 3:04:06 PM, N37.27248 E138.86183).
Figure 52. Echigo Kawaguchi: Red-tagged building (10/31/2004 3:06:12 PM, N37.27187 E138.86150).
Figure 53. Echigo Kawaguchi: The first floor of the dwelling collapsed during the earthquake (10/31/2004 3:06:54 PM, N37.27162 E138.86142).
Figure 54. Echigo Kawaguchi: The first floor of the building collapsed during the earthquake (10/31/2004 3:07:38 PM, N37.27137 E138.86124).
Figure 55. Echigo Kawaguchi: Collapsed building with heavy tile roof (10/31/2004 3:08:38 PM, N37.27180 E138.86087).
Figure 56. Echigo Kawaguchi: another view of collapsed building (10/31/2004 3:09:12 PM, N37.27197 E138.86073).
Figure 57. Location of Figures 58 to 70.
Figure 58. The Shinkansen bridge in Kawaguchi across the Ueno River (10/31/2004 3:33:54 PM, N37.26011 E138.87648).
Figure 59. The central pier of the bridge failed in bending as a plastic hinge developed at about one third above the ground level (10/31/2004 3:40:50 PM, N37.26279 E138.87848).
Figure 60. The other pier had similar bending failure but higher than the other pier. There was less concrete spalling along the neutral fiber (10/31/2004 3:48:55 PM, N37.26286 E138.87920).
Figure 61. Close view of the pier in Figure 60 (10/31/2004 3:49:09 PM, N37.26287 E138.87920).
Figure 62. A set of axial rebars stopped right at the failure section (10/31/2004 3:49:34 PM, N37.26264 E138.87926).
Figure 63. Close view of rebars in Figure 62 (10/31/2004 3:49:52 PM, N37.26256 E138.87923).
Figure 64. The light steel railway bridge adjacent to the Shinkansen bridge showed no apparent sign of damage (10/31/2004 3:53:12 PM, N37.26279 E138.87920).
Figure 65. Repair to a damaged tunnel unfortunately off limit to investigators (10/31/2004 4:16:32 PM, N37.26046 E138.88150).
Figure 66. Shear failure of a column of the Shinkansen track to the South of the Shinkansen bridge (10/31/2004 4:20:41 PM, N37.26083 E138.87921).
Figure 67. One column fails under shear whereas its neighbor did not (10/31/2004 4:23:46 PM, N37.26114 E138.88020).
Figure 68. Relative permanent lateral displacement and settlement of the soil and pier prevented the fence door from closing (10/31/2004 4:25:42 PM, N37.26148 E138.88029).
Figure 69. Toppling of monument stones due to lateral acceleration (10/31/2004 4:35:32 PM, N37.26003 E138.88039).
Figure 70. Buckling of the sidewalk due to permanent lateral ground deformation toward the Ueno River bank (10/31/2004 4:37:25 PM, N37.25956 E138.88034).
Figure 71. Cracking of the asphalt pavement due to settlement and permanent lateral ground deformation (10/31/2004 4:44:26 PM, N37.25784 E138.88190).