Your SlideShare is downloading. ×
Seismic Capacity Assessment of Sanyi Old Railway Tunnel
Seismic Capacity Assessment of Sanyi Old Railway Tunnel
Seismic Capacity Assessment of Sanyi Old Railway Tunnel
Seismic Capacity Assessment of Sanyi Old Railway Tunnel
Seismic Capacity Assessment of Sanyi Old Railway Tunnel
Seismic Capacity Assessment of Sanyi Old Railway Tunnel
Seismic Capacity Assessment of Sanyi Old Railway Tunnel
Seismic Capacity Assessment of Sanyi Old Railway Tunnel
Seismic Capacity Assessment of Sanyi Old Railway Tunnel
Seismic Capacity Assessment of Sanyi Old Railway Tunnel
Seismic Capacity Assessment of Sanyi Old Railway Tunnel
Seismic Capacity Assessment of Sanyi Old Railway Tunnel
Seismic Capacity Assessment of Sanyi Old Railway Tunnel
Seismic Capacity Assessment of Sanyi Old Railway Tunnel
Seismic Capacity Assessment of Sanyi Old Railway Tunnel
Seismic Capacity Assessment of Sanyi Old Railway Tunnel
Seismic Capacity Assessment of Sanyi Old Railway Tunnel
Seismic Capacity Assessment of Sanyi Old Railway Tunnel
Seismic Capacity Assessment of Sanyi Old Railway Tunnel
Seismic Capacity Assessment of Sanyi Old Railway Tunnel
Seismic Capacity Assessment of Sanyi Old Railway Tunnel
Seismic Capacity Assessment of Sanyi Old Railway Tunnel
Seismic Capacity Assessment of Sanyi Old Railway Tunnel
Seismic Capacity Assessment of Sanyi Old Railway Tunnel
Seismic Capacity Assessment of Sanyi Old Railway Tunnel
Seismic Capacity Assessment of Sanyi Old Railway Tunnel
Seismic Capacity Assessment of Sanyi Old Railway Tunnel
Seismic Capacity Assessment of Sanyi Old Railway Tunnel
Seismic Capacity Assessment of Sanyi Old Railway Tunnel
Seismic Capacity Assessment of Sanyi Old Railway Tunnel
Seismic Capacity Assessment of Sanyi Old Railway Tunnel
Seismic Capacity Assessment of Sanyi Old Railway Tunnel
Seismic Capacity Assessment of Sanyi Old Railway Tunnel
Seismic Capacity Assessment of Sanyi Old Railway Tunnel
Seismic Capacity Assessment of Sanyi Old Railway Tunnel
Seismic Capacity Assessment of Sanyi Old Railway Tunnel
Seismic Capacity Assessment of Sanyi Old Railway Tunnel
Upcoming SlideShare
Loading in...5
×

Thanks for flagging this SlideShare!

Oops! An error has occurred.

×
Saving this for later? Get the SlideShare app to save on your phone or tablet. Read anywhere, anytime – even offline.
Text the download link to your phone
Standard text messaging rates apply

Seismic Capacity Assessment of Sanyi Old Railway Tunnel

1,122

Published on

Lecture Details: …

Lecture Details:

Seismic Capacity Assessment of Sanyi Old Railway Tunnel

By Prof. Jin-Hung Hwang

0 Comments
0 Likes
Statistics
Notes
  • Be the first to comment

  • Be the first to like this

No Downloads
Views
Total Views
1,122
On Slideshare
0
From Embeds
0
Number of Embeds
1
Actions
Shares
0
Downloads
29
Comments
0
Likes
0
Embeds 0
No embeds

Report content
Flagged as inappropriate Flag as inappropriate
Flag as inappropriate

Select your reason for flagging this presentation as inappropriate.

Cancel
No notes for slide

Transcript

  • 1. Seismic Capacity Assessment of Sanyi Old Railway Tunnel Jin - Hung Hwang , Chih - Chieh Lu Department of Civil Engineering National Central University November 9, 2005
  • 2. DATE: 10th Nov, 2010 CET Hall
  • 3. www.cesnitsilchar.wordpress.com Fanpage MISSION 2015::NIT Silchar www.twitter.com/cesnitsilcha
  • 4. Outline Introduction Basic Data of the Tunnels Assessment Methods Analysis procedure of MCSRD Case analysis – Sanyi Old Railway Tunnel Conclusion
  • 5. Introduction Underground structures are traditionally considered to be more earthquake-resistant. Extremely strong shaking might induce damages of rock tunnel  1995 Kobe earthquake About 10 tunnels required countermeasures  1999 Taiwan Chi-Chi earthquake A total of fifty tunnels were reported to be damaged An important issue to tunnel engineers in seismic active area
  • 6. Basic Data of the tunnels Topography  DTM topography  Max. overburden depth Geology  Gravel and soft rock formations  Geotechnical parameters and wave velocities
  • 7. Cross section and lining  Cross section  Lining thickness and materials Current state of the tunnels  Cracks  Seeping of the ground water
  • 8. Assessment Methods The empirical method (Langefors and Kihlstrom, 1963)  Damage criterion  Allowable PGV for concrete and brick linings  Threshold PGA and JMA scale in the gravel and soft rock formation  Correlation of PGV with JMA intensity scale  Assessment results
  • 9. The Modified Cross-Section Racking Deformation Method (MCSRD)  Analysis procedure of MCSRD  Case analysis-Sanyi old railway tunnels
  • 10. Analysis procedure of MCSRD Set up the grid mesh Apply geostatic stresses Excavate the tunnel and install the lining support Apply a seismic shear strain Check the lining strength curves Decide the allowable seismic shear strain Calculate the allowable peak ground velocity (PGV)
  • 11. Step 1:Set up the grid mesh
  • 12. Analysis procedure of MCSRD Set up the grid mesh Apply geostatic stresses Excavate the tunnel and install the lining support Apply a seismic shear strain Check the lining strength curves Decide the allowable seismic shear strain Calculate the allowable peak ground velocity (PGV)
  • 13. Step 2:Apply geostatic stresses vσ vh Kσσ 0= vh Kσσ 0= vσ
  • 14. Analysis procedure of MCSRD Set up the grid mesh Apply geostatic stresses Excavate the tunnel and install the lining support Apply a seismic shear strain Check the lining strength curves Decide the allowable seismic shear strain Calculate the allowable peak ground velocity (PGV)
  • 15. Step 3:Excavate the tunnel and install the lining support vσ vh Kσσ 0= vh Kσσ 0= vσ
  • 16. Analysis procedure of MCSRD Set up the grid mesh Apply geostatic stresses Excavate the tunnel and install the lining support Apply a seismic shear strain Check the lining strength curves Decide the allowable seismic shear strain Calculate the allowable peak ground velocity (PGV)
  • 17. Step 4:Apply a seismic shear strain
  • 18. Analysis procedure of MCSRD Set up the grid mesh Apply geostatic stresses Excavate the tunnel and install the lining support Apply a seismic shear strain Check the lining strength curves Decide the allowable seismic shear strain Calculate the allowable peak ground velocity (PGV)
  • 19. Step 5: Check the lining strength curves Mu Pu Vu Pu
  • 20. Analysis procedure of MCSRD Set up the grid mesh Apply geostatic stresses Excavate the tunnel and install the lining support Apply a seismic shear strain Check the lining strength curves Decide the allowable seismic shear strain Calculate the allowable peak ground velocity (PGV)
  • 21. Step 6: Decide the allowable seismic shear strain  The allowable seismic shear strain is the shear strain that just causes the lining internal forces reach the limit state. Mu Pu Vu Pu
  • 22. Analysis procedure of MCSRD Set up the grid mesh Apply geostatic stresses Excavate the tunnel and install the lining support Apply a seismic shear strain Check the lining strength curves Decide the allowable seismic shear strain Calculate the allowable peak ground velocity (PGV)
  • 23. Step 7: Calculate the allowable peak ground velocity (PGV) ......(1)....................asa V γυ ×= is the allowable peak ground velocity where, is the allowable seismic shear strain aγ av sV is the wave velocity of the ground
  • 24. Case Analysis Sanyi old railway tunnels Input data The enlarged deformation behavior of tunnel The distribution of bending moment, shear force and axial force on the tunnel Check the lining strength curves The allowable peak ground velocity (PGV) Seismic capacity of the tunnels
  • 25. Input data The parameters of the ground formation Ground formation Unit weight (KN/m3 ) E (GPa) c (MPa) φo Poison ratio Vs (km/sec) Vp (km/sec) soft rock 24 1.96 0.2 32 0.3 0.6 ~ 1.5 2 ~ 3 The cross section and strength properties of the linings lining thickness (m) 0.3 0.45 0.6 0.8 1 cross section (m2 ) 0.3 0.45 0.6 0.8 1 moment inertial (m4 ) 0.00225 0.00759 0.018 0.0427 0.0833 lining strength (kg/cm2 ) 140 、 210 、 280 、 350
  • 26. The enlarged deformation behavior of tunnel original deformed Shear direction
  • 27. 0.01剪應變 The distribution of bending moment, shear force, and axial force on the tunnel 0.002剪應變 0.01剪應變Shear forceBending moment Axial force0.01剪應變
  • 28. Check the lining strength curves shear strain= 0.005 Mu (tf-m) shearstrain= 0.001 -500 0 500 1,000 1,500 2,000 2,500 3,000 0 50 100 150 200 250 300 Mu (tf-m) Pu(tf) shear st r ai n=0 -500 0 500 1,000 1,500 2,000 2,500 3,000 0 50 100 150 200 250 300 Mu (tf-m) Pu(tf) -500 0 500 1,000 1,500 2,000 2,500 3,000 0 50 100 150 200 250 300 Pu(tf) shear strain =0.005 0 50 100 150 200 0 50 100 150 200 Vu (tf) Pu(tf) Shear strain=0.002 0 50 100 150 200 0 50 100 150 200 Vu (tf) Pu(tf) shear strain=0 0 50 100 150 200 0 50 100 150 200 Vu (tf) Pu(tf)
  • 29. The allowable peak ground velocity (PGV) Bending failure mode Shearing failure mode 0 0.2 0.4 0.6 0.8 1.0 1.2 10 15 20 25 30 ground velocity(cm/s) Liningthickness(m) fc'=140 fc'=210 fc'=280 fc'=350 0 0.2 0.4 0.6 0.8 1.0 1.2 30 35 40 45 50 ground velocity(cm/s) liningthickness(m) fc'=140 fc'=210 fc'=280 fc'=350
  • 30. Seismic capacity of the tunnels gravel formation
  • 31. Seismic capacity of the tunnels soft rock formation bending failure mode shearing failing mode JMA scale Lining strength(kg/cm2 ) JMA scale Lining strength(kg/cm2 ) 140 210 280 350 140 210 280 350 Liningthickness(m) 0.3 V V V V Liningthickness(m) 0.3 V V V V 0.45 V V V V 0.45 V V V VI 0.6 V V V V 0.6 V V Ⅵ VI 0.8 V V V V 0.8 V VI VI VI 1.0 V V V V 1.0 VI VI VI VI
  • 32. Summary of the assessed seismic capacity JMA IV in gravel at least JMA V in soft rock at least One scale larger than that assessed by the empirical method
  • 33. Comparison with Field Performances in the Past Earthquakes 1935 Hsinchu-Taichung Earthquake  Historic iso-seismal map  ML=7.1,JMA=VI,PGA≥400 gal  Damage condition 1999 Chi-Chi Earthquake  ML=7.3, iso-seismal map  Estimated PGV, PGA and JMA scale  JMA=IV~V  No damage
  • 34. Comparison  Assessed JMA=IV~V at least  JMA=VI in 1935 earthquake → serious damage  JMA= IV~V in 1999 earthquake →no damage  Agree field performance well
  • 35. Conclusion  A modified cross-section racking deformation (MCSRD) method is proposed to assess the seismic capacities of the tunnel structures. It is easy ,fast, and able to automatically consider nonlinear SSI effect and to consider complex rock formation and irregular tunnel shape.
  • 36. The assessed seismic capacities of Sanyi old railway tunnels agree well with their field performances in the past earthquakes
  • 37. Thanks for your attention

×