c05 swe-ssrt-pjo kn 01 28 - fujita corporationtrack record example of swe-ssrt results...
TRANSCRIPT
Track record
Characteristics
SWE-SSRT
Summary
Seismic While Excavating using Shallow Seismic Reflection survey for Tunnels
■SWE-SSRT: 5 tunnels ■Conventional SSRT in tunnel: 11 tunnels (including TBM) ■Conventional SSRT from outside of tunnel: 5 tunnels
What is the SWE-SSRT? ■SWE-SSRT uses the excavating blasts in multiple-steps as the seismic source which allows the continual survey and prediction of tunnel geological conditions while excavating.
■ Seismic source is the excavating blasts(about 250 milliseconds delay) ■ Continual survey and prediction ahead of tunnel face without interruption of tunnel excavating work ■ A GPS time signal transmission device and Rubidium atomic clock are used to synchronize the equipment internal clock ■ The cost is about half that of the previous method
Example of SWE-SSRT results and geological revaluation on Furue-Minami tunnel
The 13th Infrastructure Technology Development Award 2011- excellence prizes -
Time recording device inside tunnel using a Rubidium clock
Rubidium clock Recoder(12ch)
geophones
Rubidium clock Recoder(12ch)
geophones
Rubidium clock Recoder (12ch)
geophones
Rubidium clock synchronizing GSP time signals at site office
GPS
Tunnel face at STA.496+95
Muddy sandstone rich Slate
SWE -‐ SSRT line -‐ 9 Vp=4000m/s
STA.495+95 STA.495+10
End of this ConstrucIon STA. 493+99
Sandstone rich Furue thrust fault
( assumed )
Forward analysis Backward analysis Fractural zone related to Furue thrust fault ?
: Heavy reflecIon Level
Comparison of the SWE -‐ SSRT results and excavaIng record Review of predicIon results
(revaluaIon) Water fall from the roof aWer excavaIon
Sandstone rich Muddy sandstone Fractural
boundary
Fractural bed boundary of sandstone rich zone and muddy sandstone zone
Line -‐ 7,8 Line -‐ 9 Forward analysis SWE -‐ SSRT Line -‐ 7,8 Vp=4000m/s
Fractural zone including underground water
地層境界 砂岩優勢
泥質砂岩
7,8 9