tunnel under sea

1. SEMINAR ON
“SEIKAN TUNNEL”
PRESENTED BY
SANKET R. PATIL
Roll No 41
GUIDED BY
Prof. S.R.BHUSKADE

2. OVER VIEW OF SEIKAN TUNNEL
 The longest and deepest transportation tunnel in the
world.
 The total length of tunnel is 53.33 km railway tunnel in
Japan, with a 23.3 km long portion under the seabed.
The track level is about 100 metres below the seabed
and 240 m below sea level.
 The islands Honshu and Hokkaido by a fixed link in
Japan.

4. SECURITY ASPECTS
 Seikan tunnel has provided CCTV camera at every 60
m,
 fire detection system ,fire fighting system with fire
hydrants at every 125 m, emergency telephone with
communication to control room at every 250m, fire
extinguishers and fire alarm at every 250 m, air
monataring system at every 500 m.

5. SITE INVESTIGATION AND UNDERSEA
GEOLOGY  Site investigation were to difficult
due 140 m water depth and
strong tidal.
 Pre investigation are include
1. Geophysical survey
2. Boring
3. Seabed observation with midget
submarine
4. Detail information of main
tunnel

6. UNDERSEA GEOLOGY
 According to Miocene Tuff the tunnel consists of
volcanic rock, pyroclastic rock, and sedimentary rock
are present.
 Which involved drilling the sea-bed, sonic survey,
submarine boring, observations using a mini-
submarine, and seismic and magnetic surveys

8. LAYOUT

9. PILOT AND SERVICE TUNNEL
 Construction access
 Maintenance

10. Construction access
 Initially only narrow gauge track was laid through the
tunnel, but in 2005 the Hokkaido Shinkansen project
started construction which included laying dual-gauge
track and extending the Shinkansen network through
the tunnel
 Two stations are within the tunnel: Tappi-Kaitei
Station and Yoshioka-Kaitei Station

11. Maintenance
 In 2002 report by Michitsugu Ikuma described, for the
undersea section, that "the tunnel structure appears to
remain in a good condition.
 The amount of flow has been decreasing with time , it
increase rigt after a large earthquake

12. GENRAL UNDERSEA SECTION
CONSTRUCTION SEQUENCING

13. DRAINAGE AND GROUTING
 DRAINAGE

14. Grouting

15. CONSTRUCTION METHODOLOGY
 Advance drill to assess
conditions
 Grouting
 Drill/blast/excavate
 Shotcrete
 Rockbolt
 Concrete Lining

19. FUTUREDEVELOPEMENT
 The tunnel will also facilitate the passing of the
Shinkansen bullet train from 2016. The current electric
system of the tunnel will be upgraded from 20kV to
25kV to facilitate the Shinkansen trains.
 Train speed will be increase up to 140km/h
 In 2035 it connect to Tokoyo

20. SUMMARY
 Increased uncertainty of ground conditions: other prediction
methods
 developed (advance boring, geochemical water analysis)
 Long uninterrupted drive: pilot and service tunnels allowed
better access to
 main tunnel and avoided potential catastrophic flooding events
 High pore water pressure: grouting employed to reduce seepage
and
 hydrostatic load on tunnel lining. System developed to
rationalize extent of grouting
 High seepage gradients can lead to large inflows in zones of
higher permeability: Prediction, grouting key to avoiding floods

21. REFERENCE
 Geotechnical report on seikan tunnel. "Tunneling and
underground space technology 1986".
 www.seikantunnel.com
 http://en.wikipedia.org/wiki/Seikan_Tunnel
 Bright Hub Engineering.com
 www.railway-technology.com

22. THANK YOU