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1 MAY 2015
SEISMIC DESIGN - INTRODUCTION1
SEISMIC DESIGN - INTRODUCTION
Dr. Ajit C. Khanse, Ph. D.
Agenda
1 MAY 2015
SEISMIC DESIGN - INTRODUCTION2
Seismic
Design
Introduction
SDC &
Design
Structural
failures
Plate
Tecton...
1 MAY 2015
SEISMIC DESIGN - INTRODUCTION3
WORLD SEISMICITY: 1900 – 2013
Seismicity refers to the geographic and historical...
1 MAY 2015
SEISMIC DESIGN - INTRODUCTION4
Volcanic arcs and oceanic trenches partly encircling the Pacific Basin form the ...
1 MAY 2015
SEISMIC DESIGN - INTRODUCTION5
The Earth is made up of a dozen major plates and several minor plates. Tectonic
...
1 MAY 2015
SEISMIC DESIGN - INTRODUCTION6
CONTINETAL DRIFT
www.tectonics.caltech.edu
1 MAY 2015
SEISMIC DESIGN - INTRODUCTION7
SAN ANDREAS FAULT, CA
The Pacific Plate (western side of San Andreas fault) is
m...
1 MAY 2015
SEISMIC DESIGN - INTRODUCTION8
1 MAY 2015
SEISMIC DESIGN - INTRODUCTION9
RUPTURE PROPAGATION With Compliments from Prof. Krishnan, Caltech
1 MAY 2015
SEISMIC DESIGN - INTRODUCTION10
EARTHQUAKE MAGNITUDE
Earthquake magnitude
M, is a measure of the
kinetic energy...
1 MAY 2015
SEISMIC DESIGN - INTRODUCTION11
EFFECTS OF EARTHQUAKE
1)Ground Shaking
2)Permanent Ground Deformation
3)Liquefa...
1 MAY 2015
SEISMIC DESIGN - INTRODUCTION12
PROGRESSIVE COLLAPSE, Mw = 7.9 With Compliments from Prof. Krishnan, Caltech
1 MAY 2015
SEISMIC DESIGN - INTRODUCTION13
GROUND SHAKING RESULTING IN STRUCTURAL FAILURE
The reverse-oblique fault line c...
1 MAY 2015
SEISMIC DESIGN - INTRODUCTION14
PERMANENT GROUND DEFORMATION
The 1999 Chi Chi, Taiwan Earthquake, Mw = 7.6
Ref:...
1 MAY 2015
SEISMIC DESIGN - INTRODUCTION15
1 MAY 2015
SEISMIC DESIGN - INTRODUCTION16
SOIL LIQUEFACTION describes a phenomenon whereby
a saturated soil substantially...
1 MAY 2015
SEISMIC DESIGN - INTRODUCTION17
A SAND BOIL is sand & water that
come out onto the ground surface
during an ear...
1 MAY 2015
SEISMIC DESIGN - INTRODUCTION18
Lateral spread or flow are terms referring to landslides that commonly form
on ...
1 MAY 2015
SEISMIC DESIGN - INTRODUCTION19
LIQUEFACTION: Lateral Spreading
Lateral spreading in the
soil beneath the roadw...
1 MAY 2015
SEISMIC DESIGN - INTRODUCTION20
BASIN EFFECT – I
Epicenter was 220 miles away from
Mexico City. Estimated 35,00...
1 MAY 2015
SEISMIC DESIGN - INTRODUCTION21
BASIN EFFECT – II
The 1985 Michoacán (Mexico) Earthquake, Mw = 8.3
Characterist...
1 MAY 2015
SEISMIC DESIGN - INTRODUCTION22
BASIN EFFECT – III
The 1985 Michoacán (Mexico) Earthquake, Mw = 8.3
 Source-av...
1 MAY 2015
SEISMIC DESIGN - INTRODUCTION23
Earthquake Magnitude vs Tsunami Intensity (1896 – 2005)
Earthquake Magnitude
RE...
1 MAY 2015
SEISMIC DESIGN - INTRODUCTION24
TSUNAMI 津波 Seismic Sea Waves
Tsunamis are ocean waves caused by large earthquak...
1 MAY 2015
SEISMIC DESIGN - INTRODUCTION25
Details of Tsunami Generation
REF: USGS
Tsunami generation from an inter-plate ...
1 MAY 2015
SEISMIC DESIGN - INTRODUCTION26
USGSThe 2004 Mw =9.2 Sumatra Earthquake: Rupture Propagation
1 MAY 2015
SEISMIC DESIGN - INTRODUCTION27
USGSThe 2004 Mw =9.2 Sumatra Earthquake: Rupture Propagation
1 MAY 2015
SEISMIC DESIGN - INTRODUCTION28
LANDSLIDES
Landslide north of Fort Funston, San Mateo Coast, CA
The 1989 Loma P...
1 MAY 2015
SEISMIC DESIGN - INTRODUCTION29
LANDSLIDE MITIGATION
The hazard from landslides can be reduced by
 avoiding co...
1 MAY 2015
SEISMIC DESIGN - INTRODUCTION30
TUNNEL DESTRUCTION
2004 Niigata Earthquake, Japan
1995 Kobe Earthquake, Japan
1 MAY 2015
SEISMIC DESIGN - INTRODUCTION31
‘There is not a fiercer hell than the failure in a great object’ – Keats
LOMA P...
1 MAY 2015
SEISMIC DESIGN - INTRODUCTION32
FEW Q&A
Q: There are no faults in the Central and Eastern United States
(CEUS)....
1 MAY 2015
SEISMIC DESIGN - INTRODUCTION33
FEW Q&A
Q: Since liner in rock is anchored to rock, the tensile hoop forces in ...
1 MAY 2015
SEISMIC DESIGN - INTRODUCTION34
FEW Q&A
Q: Since liner in rock is anchored to rock, the tensile hoop forces in ...
1 MAY 2015
SEISMIC DESIGN - INTRODUCTION35
FEW Q&A
Q: Since liner in rock is anchored to rock, the tensile hoop forces in ...
1 MAY 2015
SEISMIC DESIGN - INTRODUCTION36
SEISMIC DESIGN CATEGORY (SDC)
There are various correlations of the qualitative...
1 MAY 2015
SEISMIC DESIGN - INTRODUCTION37
MCER 1-second spectral response acceleration parameter, SM1 (%g)
Map with assoc...
1 MAY 2015
SEISMIC DESIGN - INTRODUCTION38
SEISMIC DESIGN CATEGORY (SDC)
[ASCE 7-10, AASHTO 2010]
Seismic Design Category ...
1 MAY 2015
SEISMIC DESIGN - INTRODUCTION39
LOAD CASE EXTREME EVENT - I
[AASHTO 2010]
• Designed to withstand seismic groun...
1 MAY 2015
SEISMIC DESIGN - INTRODUCTION40
LOAD CASE EXTREME EVENT - I
[AASHTO 2010]
, site-specific, deterministic
http:/...
1 MAY 2015
SEISMIC DESIGN - INTRODUCTION41
RESPONSE SPECTRA
Response spectra
establish the ground
motion shaking intensity...
1 MAY 2015
SEISMIC DESIGN - INTRODUCTION42
LOAD CASE EXTREME EVENT - II
[AASHTO 2010]
area-specific, probabilistic
http://...
1 MAY 2015
SEISMIC DESIGN - INTRODUCTION43
LOAD CASE EXTREME EVENT - III
[AASHTO 2010]
area-specific, probabilistic, all s...
1 MAY 2015
SEISMIC DESIGN - INTRODUCTION44
SEISMIC DESIGN TOOL – WORLDWIDE
http://earthquake.usgs.gov/hazards/designmaps/w...
1 MAY 2015
SEISMIC DESIGN - INTRODUCTION45
SIMPLIFIED PROCEDURE FOR SDC B & C:
Ovaling/Racking Deformation of
Circular/Rec...
1 MAY 2015
SEISMIC DESIGN - INTRODUCTION46
SIMPLIFIED PROCEDURE FOR SDC B & C:
 The values of "Peak Gravitational Acceler...
1 MAY 2015
SEISMIC DESIGN - INTRODUCTION47
FE NUMERICAL PROCEDURE FOR SDC D, E & F:
(A) Pseudo-Static Seismic Coefficient ...
1 MAY 2015
SEISMIC DESIGN - INTRODUCTION48
DYNAMIC TIME HISTORY ANALYSIS using Plaxis
Tunnel of any shape can be modeled
D...
1 MAY 2015
SEISMIC DESIGN - INTRODUCTION49
SOIL STRUCTURE INETRACTION (SSI)
The response of a structure to
earthquake shak...
1 MAY 2015
SEISMIC DESIGN - INTRODUCTION50
FLUID STRUCTURE INTERACTION (FSI)
Femarnbelt Immersed Tube Tunnel, Denmark Offs...
1 MAY 2015
SEISMIC DESIGN - INTRODUCTION51
Thank You! Q?
“Earthquake effects on structures
systematically bring out the mi...
1 MAY 2015
SEISMIC DESIGN - INTRODUCTION52
DESIGN STANDARDS
(1)AASHTO Technical Manual for Design & Construction of Road T...
1 MAY 2015
SEISMIC DESIGN - INTRODUCTION53
MCER = Risk-targeted Maximum Considered Earthquake Ground Motion.
Design respon...
Presentation Title
DESIGN RESPONSE SPECTRA
54
for TS ≤ T ≤ TL (Eq. 11.4-10)
for T > TL (Eq. 11.4-11)
SDS = ⅔.Fa.CRS.SSUH o...
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Seismic Design - Introduction

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Seismic Design - Introduction

  1. 1. 1 MAY 2015 SEISMIC DESIGN - INTRODUCTION1 SEISMIC DESIGN - INTRODUCTION Dr. Ajit C. Khanse, Ph. D.
  2. 2. Agenda 1 MAY 2015 SEISMIC DESIGN - INTRODUCTION2 Seismic Design Introduction SDC & Design Structural failures Plate Tectonics Seismicity Fault Rupture ENHANCE OUR STRENGTH TO ONE OF THE TOPMOST International tunnel solution providers
  3. 3. 1 MAY 2015 SEISMIC DESIGN - INTRODUCTION3 WORLD SEISMICITY: 1900 – 2013 Seismicity refers to the geographic and historical distribution of earthquakes. The dots represent the epicenters of significant earthquakes. It is apparent that the locations of the great majority of earthquakes correspond to the boundaries between plates. Mw ≥ 7.0
  4. 4. 1 MAY 2015 SEISMIC DESIGN - INTRODUCTION4 Volcanic arcs and oceanic trenches partly encircling the Pacific Basin form the so- called Ring of Fire, a zone of frequent earthquakes and volcanic eruptions. RING OF FIRE
  5. 5. 1 MAY 2015 SEISMIC DESIGN - INTRODUCTION5 The Earth is made up of a dozen major plates and several minor plates. Tectonic plates are constantly on the move. The fastest tectonic plate constantly races along at 6” per year while the slowest plates crawl at less than1” per year [USGS] PLATE TECTONICS
  6. 6. 1 MAY 2015 SEISMIC DESIGN - INTRODUCTION6 CONTINETAL DRIFT www.tectonics.caltech.edu
  7. 7. 1 MAY 2015 SEISMIC DESIGN - INTRODUCTION7 SAN ANDREAS FAULT, CA The Pacific Plate (western side of San Andreas fault) is moving horizontally in a northerly direction relative to the North American Plate (eastern side of fault)
  8. 8. 1 MAY 2015 SEISMIC DESIGN - INTRODUCTION8
  9. 9. 1 MAY 2015 SEISMIC DESIGN - INTRODUCTION9 RUPTURE PROPAGATION With Compliments from Prof. Krishnan, Caltech
  10. 10. 1 MAY 2015 SEISMIC DESIGN - INTRODUCTION10 EARTHQUAKE MAGNITUDE Earthquake magnitude M, is a measure of the kinetic energy released by an earthquake. Due to limitations in the ability of some recording instruments to measure values above a certain amplitude, some of these magnitude scales tend to reach an asymptotic upper limit. To correct this, the moment magnitude, Mw, scale was developed.
  11. 11. 1 MAY 2015 SEISMIC DESIGN - INTRODUCTION11 EFFECTS OF EARTHQUAKE 1)Ground Shaking 2)Permanent Ground Deformation 3)Liquefaction (a) Sand Boils (b) Lateral Spreading Landslides (c) Graben and Horst 4)Basin Effect 5)Tsunami 6)Landslides 7)Structural Destruction
  12. 12. 1 MAY 2015 SEISMIC DESIGN - INTRODUCTION12 PROGRESSIVE COLLAPSE, Mw = 7.9 With Compliments from Prof. Krishnan, Caltech
  13. 13. 1 MAY 2015 SEISMIC DESIGN - INTRODUCTION13 GROUND SHAKING RESULTING IN STRUCTURAL FAILURE The reverse-oblique fault line crosses the largest concrete gravity 石岡 Shigung dam in Taiwan. The eastern 80 % of the dam is uplifted by about 33 ft and the western part by about 10 ft. At fault-line, the concrete dam wall was cut off and 23 ft difference appeared in the elevation. The 1999 Chi Chi, Taiwan Earthquake, Mw = 7.6 www.infra.kochi-tech.ac.jp/
  14. 14. 1 MAY 2015 SEISMIC DESIGN - INTRODUCTION14 PERMANENT GROUND DEFORMATION The 1999 Chi Chi, Taiwan Earthquake, Mw = 7.6 Ref: kyoto-u.ac.jp
  15. 15. 1 MAY 2015 SEISMIC DESIGN - INTRODUCTION15
  16. 16. 1 MAY 2015 SEISMIC DESIGN - INTRODUCTION16 SOIL LIQUEFACTION describes a phenomenon whereby a saturated soil substantially loses strength and stiffness in response to earthquake shaking or other sudden change in stress condition, causing it to behave like a liquid.
  17. 17. 1 MAY 2015 SEISMIC DESIGN - INTRODUCTION17 A SAND BOIL is sand & water that come out onto the ground surface during an earthquake as a result of liquefaction at shallow depth. . .
  18. 18. 1 MAY 2015 SEISMIC DESIGN - INTRODUCTION18 Lateral spread or flow are terms referring to landslides that commonly form on gentle slopes and that have rapid fluid-like flow movement, like water. LIQUEFACTION: Lateral Spreading Landslides
  19. 19. 1 MAY 2015 SEISMIC DESIGN - INTRODUCTION19 LIQUEFACTION: Lateral Spreading Lateral spreading in the soil beneath the roadway embankment caused the embankment to be pulled apart, producing the large crack down the center of the road. (REF: USGS) The 1964 Alaska Earthquake, Mw = 7.9
  20. 20. 1 MAY 2015 SEISMIC DESIGN - INTRODUCTION20 BASIN EFFECT – I Epicenter was 220 miles away from Mexico City. Estimated 35,000 people died in Mexico City, where 412 multistory (8 to 25 floors) buildings collapsed completely and another 3,124 were seriously damaged. (USGS) 21-story, steel-frame building 15-story reinforced concrete building 8-story RC building The 1985 Michoacán (Mexico) Earthquake, Mw = 8.3
  21. 21. 1 MAY 2015 SEISMIC DESIGN - INTRODUCTION21 BASIN EFFECT – II The 1985 Michoacán (Mexico) Earthquake, Mw = 8.3 Characteristics of the soil profiles • Extremely soft, saturated surface clays • At some places Plasticity Index ≈ 300 • Friction angles as low as, ϕ = 5-15o Zone Depth (ft) Eff. Vs (ft/s) Predominant period (s) Transition 43 285 0.6 Lake 125 250 2.0 Deep Lake 185 200 3.4 Dynamic characteristics of Soil deposits play vital role [Aviles and Perez-Rocha 1998] Map of seismic zonation and isoperiod curves (in sec) of Mexico City
  22. 22. 1 MAY 2015 SEISMIC DESIGN - INTRODUCTION22 BASIN EFFECT – III The 1985 Michoacán (Mexico) Earthquake, Mw = 8.3  Source-averaged basin amplification is period-dependent, with the highest amplifications occurring for the longest periods and greatest basin depths.  Relative to the very-hard rock reference structure, general maximum amplification is about a factor of 8. At Mexico city (1985 Michoacán earthquake), seismic motion was amplified up to a factor of 60 compared to the bedrock. [Aviles and Perez-Rocha 1998]
  23. 23. 1 MAY 2015 SEISMIC DESIGN - INTRODUCTION23 Earthquake Magnitude vs Tsunami Intensity (1896 – 2005) Earthquake Magnitude REF: USGS
  24. 24. 1 MAY 2015 SEISMIC DESIGN - INTRODUCTION24 TSUNAMI 津波 Seismic Sea Waves Tsunamis are ocean waves caused by large earthquakes & landslides that occur near or under the ocean. Generated when thrust faults associated with convergent or destructive plate boundaries move abruptly, resulting in water displacement, owing to the vertical component of movement involved. Sumatra and the Andaman Islands are part of an island arc. REF: USGS
  25. 25. 1 MAY 2015 SEISMIC DESIGN - INTRODUCTION25 Details of Tsunami Generation REF: USGS Tsunami generation from an inter-plate thrust fault The displacement of rock surrounding the inter-plate thrust Diagram of tsunami splitting, soon after generation
  26. 26. 1 MAY 2015 SEISMIC DESIGN - INTRODUCTION26 USGSThe 2004 Mw =9.2 Sumatra Earthquake: Rupture Propagation
  27. 27. 1 MAY 2015 SEISMIC DESIGN - INTRODUCTION27 USGSThe 2004 Mw =9.2 Sumatra Earthquake: Rupture Propagation
  28. 28. 1 MAY 2015 SEISMIC DESIGN - INTRODUCTION28 LANDSLIDES Landslide north of Fort Funston, San Mateo Coast, CA The 1989 Loma Prieta Earthquake Landslides occur due to ground shaking alone or shaking-caused dilation of soil materials, which allows rapid infiltration of water. REF: USGS
  29. 29. 1 MAY 2015 SEISMIC DESIGN - INTRODUCTION29 LANDSLIDE MITIGATION The hazard from landslides can be reduced by  avoiding construction on steep slopes and existing landslides  stabilizing the slopes. Slope stability is increased when  a retaining structure &/or the weight of a soil/rock berm are placed at the toe of the landslide.  when mass is removed from the top of the slope.  When ground water is prevented from rising in the landslide mass.
  30. 30. 1 MAY 2015 SEISMIC DESIGN - INTRODUCTION30 TUNNEL DESTRUCTION 2004 Niigata Earthquake, Japan 1995 Kobe Earthquake, Japan
  31. 31. 1 MAY 2015 SEISMIC DESIGN - INTRODUCTION31 ‘There is not a fiercer hell than the failure in a great object’ – Keats LOMA PRIETA 1989, Mw=6.93KOBE, JAPAN 1995, Mw= 6.9
  32. 32. 1 MAY 2015 SEISMIC DESIGN - INTRODUCTION32 FEW Q&A Q: There are no faults in the Central and Eastern United States (CEUS). Earthquakes are rare. Is seismic design mandatory? • An intraplate earthquake occurs in the interior of a tectonic plate, which could be due to unknown causative fault buried inside a plate. • Recall Load Combinations of AASHTO 2010 & ASCE 7-10. • Site-specific investigation of Seismic Design Category (SDC) determines the type of design procedure. Q: Traditionally unreinforced concrete liner has been provided in some cases – is it acceptable? AASHTO 2010 has no comment. ACI 318-14 Ch. 18 on ‘Earthquake Resistant Structures’ does not allow unreinforced concrete. Further, the ovaling deformation may induce considerable tensile hoop forces.
  33. 33. 1 MAY 2015 SEISMIC DESIGN - INTRODUCTION33 FEW Q&A Q: Since liner in rock is anchored to rock, the tensile hoop forces in liner are apparent during ovaling response. Do we have these for liner in soil? Liner in Soil
  34. 34. 1 MAY 2015 SEISMIC DESIGN - INTRODUCTION34 FEW Q&A Q: Since liner in rock is anchored to rock, the tensile hoop forces in liner are apparent during ovaling response. Do we have these for liner in soil? Liner in Soil
  35. 35. 1 MAY 2015 SEISMIC DESIGN - INTRODUCTION35 FEW Q&A Q: Since liner in rock is anchored to rock, the tensile hoop forces in liner are apparent during ovaling response. Do we have these for liner in soil? F = m.a Forces due to motion, Liner in Soil T T
  36. 36. 1 MAY 2015 SEISMIC DESIGN - INTRODUCTION36 SEISMIC DESIGN CATEGORY (SDC) There are various correlations of the qualitative Modified Mercalli Intensity (MMI) with quantitative characterizations of ground-shaking limits for the various SDCs. MMI V No real damage SDC A 0 < SM1 <0.1g MMI VI Light nonstructural damage SDC B 0.1g < SM1 < 0.2g MMI VII Hazardous nonstructural damage SDC C 0.2g < SM1 < 0.3g MMI VIII Hazardous damage to susceptible structures SDC D 0.3 < SM1 < 1.12g MMI IX Hazardous damage to robust structures SDC E SM1 > 1.125g [§11.6, ASCE 7-10]
  37. 37. 1 MAY 2015 SEISMIC DESIGN - INTRODUCTION37 MCER 1-second spectral response acceleration parameter, SM1 (%g) Map with associated regions of Seismic Design Category, assuming Site Class D conditions
  38. 38. 1 MAY 2015 SEISMIC DESIGN - INTRODUCTION38 SEISMIC DESIGN CATEGORY (SDC) [ASCE 7-10, AASHTO 2010] Seismic Design Category (SDC) depends upon  Topographic location,  Site soil class,  Occupancy (risk) category,  Deterministic design spectral response parameter at short period SDS and that at 1-sec period SD1. The design requirements depending upon SDC:  SDC A: No seismic design. Certain provisions shall be met.  SDC B & C: Analytical closed-form analysis procedure.  SDC D, E & F: The finite-element or finite-difference numerical modelling approach.
  39. 39. 1 MAY 2015 SEISMIC DESIGN - INTRODUCTION39 LOAD CASE EXTREME EVENT - I [AASHTO 2010] • Designed to withstand seismic ground motions with a Return Period of 2,500 years, corresponding to 2% probability of exceedance in 50 years. • Values from Maximum Considered Earthquake (MCER) shall be used for Load Case Extreme Event I. The recurrence interval, or Return Period (RP), is the average time span between earthquake occurrences. In 1 100 T RP PE         For PE = 2 and T = 50 years, RP ≈ 2,500 years
  40. 40. 1 MAY 2015 SEISMIC DESIGN - INTRODUCTION40 LOAD CASE EXTREME EVENT - I [AASHTO 2010] , site-specific, deterministic http://earthquake.usgs.gov/designmaps/us/application.php
  41. 41. 1 MAY 2015 SEISMIC DESIGN - INTRODUCTION41 RESPONSE SPECTRA Response spectra establish the ground motion shaking intensity level and are used for deriving other ground motion parameters, e.g., PGA / SM1 is used to find PGV, shear strain, etc. Response spectra are used as target spectra for generating design ground motion time histories for refined numerical analysis Minimum three points are required to establish Response Spectra
  42. 42. 1 MAY 2015 SEISMIC DESIGN - INTRODUCTION42 LOAD CASE EXTREME EVENT - II [AASHTO 2010] area-specific, probabilistic http://geohazards.usgs.gov/hazards/apps/cmaps  A 'realistic design basis earthquake', typically taken as occurring once in a period equal to about three times the design life (3 x 100).  For CEUSA, the Return Period of 500 years i.e., 10% probability of exceedance in 50 years.  The values for site class B are obtained from USGS hazard maps.  Values for other soil class are derived from Ch. 11 of ASCE 7-10
  43. 43. 1 MAY 2015 SEISMIC DESIGN - INTRODUCTION43 LOAD CASE EXTREME EVENT - III [AASHTO 2010] area-specific, probabilistic, all soil types http://geohazards.usgs.gov/hazardtool/application.php  The Extreme Event III and Construction Strength I combination should consider “a smaller earthquake as a static load” to be combined with other loads  A Return Period of 10 years i.e., 99% probability of exceedance in 50 years  The values for all site classes for any probability are obtained from USGS hazard maps.
  44. 44. 1 MAY 2015 SEISMIC DESIGN - INTRODUCTION44 SEISMIC DESIGN TOOL – WORLDWIDE http://earthquake.usgs.gov/hazards/designmaps/wwdesign.php Salah Bey Cable Bridge, Constantine, Algeria
  45. 45. 1 MAY 2015 SEISMIC DESIGN - INTRODUCTION45 SIMPLIFIED PROCEDURE FOR SDC B & C: Ovaling/Racking Deformation of Circular/Rectangular c/section to Vertically Propagating Shear Waves Axial/Curvature Deformation Along Tunnel Due to Traveling Waves
  46. 46. 1 MAY 2015 SEISMIC DESIGN - INTRODUCTION46 SIMPLIFIED PROCEDURE FOR SDC B & C:  The values of "Peak Gravitational Acceleration (PGA)" and "Maximum spectral response at 1-s period (SM1)" are obtained from the site-specific, deterministic hazard analysis from USGS.  SM1 is used to calculate the shear wave peak particle velocity Vs of soil  Using closed-form analytical equations, the free-field shear strain, γ at the required depth is evaluated from PGA and Vs, separately.  Bending moments and axial hoop forces are evaluated from γ using closed-form equations.  Seismic forces are added to static loads with appropriate load factors. Ch. 13 of AASHTO 2010
  47. 47. 1 MAY 2015 SEISMIC DESIGN - INTRODUCTION47 FE NUMERICAL PROCEDURE FOR SDC D, E & F: (A) Pseudo-Static Seismic Coefficient Deformation Method for (a) underground structures buried at shallow depths, (b) when the subsurface conditions are not highly variable, nor ground stability is a concern, (c) simple and non-critical structures, (d) low seismic area (B) Dynamic Time History Analysis: In a dynamic time history analysis, the entire soil-structure system is subject to dynamic excitations using ground motion time histories as input at the base of the soil-structure system
  48. 48. 1 MAY 2015 SEISMIC DESIGN - INTRODUCTION48 DYNAMIC TIME HISTORY ANALYSIS using Plaxis Tunnel of any shape can be modeled Dynamic Load input options: 1) Simple sinusoidal wave 2) Any time-dependent force 3) Earthquake Time History
  49. 49. 1 MAY 2015 SEISMIC DESIGN - INTRODUCTION49 SOIL STRUCTURE INETRACTION (SSI) The response of a structure to earthquake shaking is affected by interactions between three linked systems: 1) the structure, 2) the foundation, and 3) the geologic media underlying and surrounding the foundation. [Fig. from H. Allison Smith & Wen-Hwa Wu, 1997]
  50. 50. 1 MAY 2015 SEISMIC DESIGN - INTRODUCTION50 FLUID STRUCTURE INTERACTION (FSI) Femarnbelt Immersed Tube Tunnel, Denmark Offshore structures
  51. 51. 1 MAY 2015 SEISMIC DESIGN - INTRODUCTION51 Thank You! Q? “Earthquake effects on structures systematically bring out the mistakes made in design and construction, even the minutest mistakes” – Newmark and Rosenblueth
  52. 52. 1 MAY 2015 SEISMIC DESIGN - INTRODUCTION52 DESIGN STANDARDS (1)AASHTO Technical Manual for Design & Construction of Road Tunnels – Civil Elements 2010 (2)FHWA-NHI-11-032, LRFD Seismic Analysis and Design of Transportation Geotechnical Features and Structural Foundations, 2011 (3)FHWA-HRT-05-067 Seismic Retrofitting Manual for Highway Structures: Part 2 – Tunnels, Retaining Structures, Slopes, Culverts & Roadways, 2005 (4) ASCE/SEI 7-10 Minimum Design Loads for Buildings and Other Structures (5)AASHTO LRFD Bridge Design Specifications, 6th Edition, 2014 (6) AASHTO LRFD Seismic Bridge Design, 2nd Edition, 2011 (7)AISC 341-10 Seismic Provisions for Structural Steel Buildings, 2010 (8)ACI 318-14 Building Code Requirements for Structural Concrete & Commentary
  53. 53. 1 MAY 2015 SEISMIC DESIGN - INTRODUCTION53 MCER = Risk-targeted Maximum Considered Earthquake Ground Motion. Design response spectrum shall be determined by dividing ordinates of MCER response spectrum by 1.5. FEW NOTATIONS & DEFINATIONS CR = risk coefficient; see Section 21.2.1.1 CRS = mapped value of the risk coefficient at short periods as defined by Figure 22-3 CR1 = mapped value of the risk coefficient at a period of 1 second as defined by Figure 22-4 SSD = mapped deterministic, 5 percent damped, spectral response acceleration parameter at short periods as defined in Section 11.4.1 SSUH = mapped uniform-hazard, 5 percent damped, spectral response acceleration parameter at short periods as defined in Section 11.4.1 S1D = mapped deterministic, 5 percent damped, spectral response acceleration parameter at a period of 1 second as defined in Section 11.4.1 S1UH = mapped uniform-hazard, 5 percent damped, spectral response acceleration parameter at a period of 1 second as defined in Section 11.4.1 SS = 5 percent damped, spectral response acceleration parameter at short periods as defined in Sec. 11.4.3 S1 = spectral response acceleration parameter at a period of 1 second as defined in Section 11.4.3 SaM = the site-specific MCER spectral response acceleration at any period SMS = the MCER, 5 percent damped, spectral response acceleration parameter at short periods adjusted for target risk and site-class effects as defined in Section 11.4.3 SM1 = the MCER, 5 percent damped, spectral response acceleration parameter at a period of 1 second adjusted for target risk and site-class effects as defined in Section 11.4.3 [Sec. 11.2, 11.3, ASCE 7-10]
  54. 54. Presentation Title DESIGN RESPONSE SPECTRA 54 for TS ≤ T ≤ TL (Eq. 11.4-10) for T > TL (Eq. 11.4-11) SDS = ⅔.Fa.CRS.SSUH or ⅔.Fa.SSD, lesser. (Eq. 11.4-1, 11.4-2, Table 11.4-1) 0 0 0.4 0.6 ( .11.4 9)DSa T S for T T EqS T          SD1 = ⅔.Fv.CR1.S1UH or ⅔.Fv.S1D, lesser. (Eq. 11.4-3, 11.4-4, Table 11.4-2) [Sec. 11.4, ASCE 7-10] Response Spectra

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