seismic design of tunnels - tunneling short course
TRANSCRIPT
Mike Wongkaew, PhD, PE, SEAssociate Vice PresidentNational Tunnel Practice Lead – NW
Seismic Design of Tunnels
Tuesday 9/10/2019, 3:30 p.m. – 4:15 p.m.
2 12th Annual Breakthroughs in Tunneling Short Course – Seismic Design of Tunnels and Shafts – Mike Wongkaew, PhD, PE, SE
Seismic Environment
Source: https://earthquake.usgs.gov/hazards/hazmaps/conterminous/index.php#2014
3 12th Annual Breakthroughs in Tunneling Short Course – Seismic Design of Tunnels and Shafts – Mike Wongkaew, PhD, PE, SE
Seismic Performance of Above Ground Structures - Inertia Effects
4 12th Annual Breakthroughs in Tunneling Short Course – Seismic Design of Tunnels and Shafts – Mike Wongkaew, PhD, PE, SE
Seismic Performance of Underground Structures
Source: Dean et al (2006), Power et al (1998)
5 12th Annual Breakthroughs in Tunneling Short Course – Seismic Design of Tunnels and Shafts – Mike Wongkaew, PhD, PE, SE
Seismic Effects on Underground Structures – Imposed Deformation
Source: Shamsabadi et al (2001) Source: JSCE (2008)
6 12th Annual Breakthroughs in Tunneling Short Course – Seismic Design of Tunnels and Shafts – Mike Wongkaew, PhD, PE, SE
Seismic Effects on Underground Structures – Imposed Deformation
Source: JSCE (2008)
Source: Iida et al (1996)
7 12th Annual Breakthroughs in Tunneling Short Course – Seismic Design of Tunnels and Shafts – Mike Wongkaew, PhD, PE, SE
Work Flow for Seismic Design of Underground StructuresDetermine Seismic Environment
• Design Criteria• Maximum Design
Earthquake (MDE)• Operating Design
Earthquake (ODE)• Seismic Hazard
Analysis• Deterministic SHA• Probabilistic SHA
• Ground Motion Parameters• Acceleration,
velocity, displacement
• Response spectra, motion time history
• Spatial incoherence of ground motion
Evaluate Ground Response to Shaking
• Ground Failure• Liquefaction• Slope instability• Fault displacement
• Ground Shaking and Deformation• Longitudinal
extension/compression
• Longitudinal bending• Racking / Ovaling
Evaluate Underground Structure Response to Seismic Shaking
• Seismic design loading criteria• Loading criteria for
MDE• Loading criteria for
ODE• Underground Structure
Response to Ground Deformation• Free-Field
Deformation Approach
• Soil-Structure Interaction Approach
• Special Seismic Design Issues
Polic
ySe
ism
olog
y
Geo
tech
nica
l Ear
thqu
ake
Engi
neer
ing
Tunn
el S
truct
ural
Eng
inee
ring
8 12th Annual Breakthroughs in Tunneling Short Course – Seismic Design of Tunnels and Shafts – Mike Wongkaew, PhD, PE, SE
Determine Seismic EnvironmentDetermine Seismic Environment
• Design Criteria• Maximum Design
Earthquake (MDE)• Operating Design
Earthquake (ODE)• Seismic Hazard
Analysis• Deterministic SHA• Probabilistic SHA
• Ground Motion Parameters• Acceleration,
velocity, displacement
• Response spectra, motion time history
• Spatial incoherence of ground motion
Evaluate Ground Response to Shaking
• Ground Failure• Liquefaction• Slope instability• Fault displacement
• Ground Shaking and Deformation• Longitudinal
extension/compression
• Longitudinal bending• Racking / Ovaling
Evaluate Underground Structure Response to Seismic Shaking
• Seismic design loading criteria• Loading criteria for
MDE• Loading criteria for
ODE• Underground Structure
Response to Ground Deformation• Free-Field
Deformation Approach
• Soil-Structure Interaction Approach
• Special Seismic Design Issues
Polic
ySe
ism
olog
y
Geo
tech
nica
l Ear
thqu
ake
Engi
neer
ing
Tunn
el S
truct
ural
Eng
inee
ring
Design return periods for recent major mass transit projects:
MDE = 2,500 years (4% in 100 years)ODE = 150 years (50% in 100 years)
9 12th Annual Breakthroughs in Tunneling Short Course – Seismic Design of Tunnels and Shafts – Mike Wongkaew, PhD, PE, SE
Determine Surface Ground Motion Parameters - Acceleration
Source: https://earthquake.usgs.gov/hazards/hazmaps/conterminous/index.php#2014
10 12th Annual Breakthroughs in Tunneling Short Course – Seismic Design of Tunnels and Shafts – Mike Wongkaew, PhD, PE, SE
Determine Surface Ground Motion Parameters – Velocity & Displ.
Source: FHWA-NHI-09-010 Road Tunnel Manual (2009)
11 12th Annual Breakthroughs in Tunneling Short Course – Seismic Design of Tunnels and Shafts – Mike Wongkaew, PhD, PE, SE
Evaluate Ground Response to ShakingDetermine Seismic Environment
• Design Criteria• Maximum Design
Earthquake (MDE)• Operating Design
Earthquake (ODE)• Seismic Hazard
Analysis• Deterministic SHA• Probabilistic SHA
• Ground Motion Parameters• Acceleration,
velocity, displacement
• Response spectra, motion time history
• Spatial incoherence of ground motion
Evaluate Ground Response to Shaking
• Ground Failure• Liquefaction• Slope instability• Fault displacement
• Ground Shaking and Deformation• Longitudinal
extension/compression
• Longitudinal bending• Racking / Ovaling
Evaluate Underground Structure Response to Seismic Shaking
• Seismic design loading criteria• Loading criteria for
MDE• Loading criteria for
ODE• Underground Structure
Response to Ground Deformation• Free-Field
Deformation Approach
• Soil-Structure Interaction Approach
• Special Seismic Design Issues
Polic
ySe
ism
olog
y
Geo
tech
nica
l Ear
thqu
ake
Engi
neer
ing
Tunn
el S
truct
ural
Eng
inee
ring
12 12th Annual Breakthroughs in Tunneling Short Course – Seismic Design of Tunnels and Shafts – Mike Wongkaew, PhD, PE, SE
Ground Shaking and Deformation – Seismic WavesEvaluate Ground Response to Shaking
• Ground Failure• Liquefaction• Slope instability• Fault displacement
• Ground Shaking and Deformation• Longitudinal
extension/compression
• Longitudinal bending• Racking / Ovaling
Evaluate Underground Structure Response to Seismic Shaking
• Seismic design loading criteria• Loading criteria for
MDE• Loading criteria for
ODE• Underground Structure
Response to Ground Deformation• Free-Field
Deformation Approach
• Soil-Structure Interaction Approach
• Special Seismic Design Issues
Geo
tech
nica
l Ear
thqu
ake
Engi
neer
ing
Tunn
el S
truct
ural
Eng
inee
ring
Source: Kawashima
13 12th Annual Breakthroughs in Tunneling Short Course – Seismic Design of Tunnels and Shafts – Mike Wongkaew, PhD, PE, SE
Directions of Seismic Wave Propagation – Design Implications
14 12th Annual Breakthroughs in Tunneling Short Course – Seismic Design of Tunnels and Shafts – Mike Wongkaew, PhD, PE, SE
Free-field Strains and Curvatures - Simplified Harmonic Waves
Source: Hashash et al (2001) and St John and Zahrah (1987)
15 12th Annual Breakthroughs in Tunneling Short Course – Seismic Design of Tunnels and Shafts – Mike Wongkaew, PhD, PE, SE
Site Response Analysis (e.g. SHAKE, Opensees, DeepSoil)
16 12th Annual Breakthroughs in Tunneling Short Course – Seismic Design of Tunnels and Shafts – Mike Wongkaew, PhD, PE, SE
Evaluate Underground Structure Response to Seismic ShakingDetermine Seismic Environment
• Design Criteria• Maximum Design
Earthquake (MDE)• Operating Design
Earthquake (ODE)• Seismic Hazard
Analysis• Deterministic SHA• Probabilistic SHA
• Ground Motion Parameters• Acceleration,
velocity, displacement
• Response spectra, motion time history
• Spatial incoherence of ground motion
Evaluate Ground Response to Shaking
• Ground Failure• Liquefaction• Slope instability• Fault displacement
• Ground Shaking and Deformation• Longitudinal
extension/compression
• Longitudinal bending• Racking / Ovaling
Evaluate Underground Structure Response to Seismic Shaking
• Seismic design loading criteria• Loading criteria for
MDE• Loading criteria for
ODE• Underground Structure
Response to Ground Deformation• Free-Field
Deformation Approach
• Soil-Structure Interaction Approach
• Special Seismic Design Issues
Polic
ySe
ism
olog
y
Geo
tech
nica
l Ear
thqu
ake
Engi
neer
ing
Tunn
el S
truct
ural
Eng
inee
ring
17 12th Annual Breakthroughs in Tunneling Short Course – Seismic Design of Tunnels and Shafts – Mike Wongkaew, PhD, PE, SE
Underground Structure’s Response to Ground DeformationEvaluate Underground Structure Response to Seismic Shaking
• Seismic design loading criteria• Loading criteria for
MDE• Loading criteria for
ODE• Underground Structure
Response to Ground Deformation• Free-Field
Deformation Approach
• Soil-Structure Interaction Approach
• Special Seismic Design IssuesTunn
el S
truct
ural
Eng
inee
ring
18 12th Annual Breakthroughs in Tunneling Short Course – Seismic Design of Tunnels and Shafts – Mike Wongkaew, PhD, PE, SE
Rectangular Section
Source: Wang (1993)
19 12th Annual Breakthroughs in Tunneling Short Course – Seismic Design of Tunnels and Shafts – Mike Wongkaew, PhD, PE, SE
Ratio of Underground Structure Deformation vs Free Field
Tunnel deformation could be up to 2.4x free field deformation
Dependent on stiffness ratio
Additional reference for circular and rectangular sections:− Penzien, 2000, Seismically
Induced Racking of Tunnel Linings
Closed form approximation for longitudinal (snaking) deformation
20 12th Annual Breakthroughs in Tunneling Short Course – Seismic Design of Tunnels and Shafts – Mike Wongkaew, PhD, PE, SE
Work Flow for Seismic Design of Underground StructuresDetermine Seismic Environment
• Design Criteria• Maximum Design
Earthquake (MDE)• Operating Design
Earthquake (ODE)• Seismic Hazard
Analysis• Deterministic SHA• Probabilistic SHA
• Ground Motion Parameters• Acceleration,
velocity, displacement
• Response spectra, motion time history
• Spatial incoherence of ground motion
Evaluate Ground Response to Shaking
• Ground Failure• Liquefaction• Slope instability• Fault displacement
• Ground Shaking and Deformation• Longitudinal
extension/compression
• Longitudinal bending• Racking / Ovaling
Evaluate Underground Structure Response to Seismic Shaking
• Seismic design loading criteria• Loading criteria for
MDE• Loading criteria for
ODE• Underground Structure
Response to Ground Deformation• Free-Field
Deformation Approach
• Soil-Structure Interaction Approach
• Special Seismic Design Issues
Polic
ySe
ism
olog
y
Geo
tech
nica
l Ear
thqu
ake
Engi
neer
ing
Tunn
el S
truct
ural
Eng
inee
ring
21 12th Annual Breakthroughs in Tunneling Short Course – Seismic Design of Tunnels and Shafts – Mike Wongkaew, PhD, PE, SE
Example #1 – Cut and Cover Subway Station (Los Angeles)
22 12th Annual Breakthroughs in Tunneling Short Course – Seismic Design of Tunnels and Shafts – Mike Wongkaew, PhD, PE, SE
Example #1 – Seismic Soil-Structure Interaction Analysis
Source: Tsai et al (2015)
23 12th Annual Breakthroughs in Tunneling Short Course – Seismic Design of Tunnels and Shafts – Mike Wongkaew, PhD, PE, SE
Example #2 – Pump Station (Portland, OR)
220 MGD pump station 135 ft dia. X 162 ft
deep Subsurface:
− Fill 25 ft− Alluvium 115 ft− Troutdale formation
185 ft− Mudstone
Avg. shear wave velocity = 550 ft/s
PGA = 0.34 g
24 12th Annual Breakthroughs in Tunneling Short Course – Seismic Design of Tunnels and Shafts – Mike Wongkaew, PhD, PE, SE
Example #2 – Seismic Soil Structure Interaction Analysis
FEA model Solid elements for
soils, 9x shaft diameter wide
Shell elements for shaft walls and slabs
Free field deformation applied to the side boundaries
25 12th Annual Breakthroughs in Tunneling Short Course – Seismic Design of Tunnels and Shafts – Mike Wongkaew, PhD, PE, SE
Example #2 – Seismic Soil Structure Interaction Analysis
1.2” differential displacement (top vs bottom of shaft)
Principal stresses in shaft walls (psi) well within concrete capacity
X
YZ
-29.
-25.
-20.
-15.
-10.
-5.
0.
5.
10.
15.
20.
25.
29.
-31.
-30.
-24.
-18.
-12.
-6.
0.
6.
12.
18.
24.
30.
31.
Use of simple 3D model helped us understand seismic performance (and reduce wall thickness & cost)
Source: Wongkaew and Owyang, 2004
26 12th Annual Breakthroughs in Tunneling Short Course – Seismic Design of Tunnels and Shafts – Mike Wongkaew, PhD, PE, SE
Example #3 – SEM Tunnel Adjacent to Building Basement (Wash.)
Soil-tunnel-building FEA model Free field displacement applied at left
and right boundaries Evaluated seismic deformation and
interaction of basement and tunnel
Photo 1Source: Yang and Penrice (2014)
27 12th Annual Breakthroughs in Tunneling Short Course – Seismic Design of Tunnels and Shafts – Mike Wongkaew, PhD, PE, SE
Key Takeaways
• “Ground Displacement Problem”
• NOT “Inertial Problem”
• Consider Soil-structure Interaction
• Design underground structures to accommodate displacement demand
Determine Seismic Environment
Evaluate Ground Response to Shaking
Evaluate Underground Structure Response to Seismic Shaking