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From Theory to Practice: Performance-based Kinematic Pile Response - Kevin Franke
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From Theory to Practice: Performance-based Kinematic Pile Response - Kevin Franke

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2013 EERI Annual Meeting Session: 2011-2012 EERI/FEMA NEHRP Graduate Fellow

2013 EERI Annual Meeting Session: 2011-2012 EERI/FEMA NEHRP Graduate Fellow

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From Theory to Practice: Performance-based Kinematic Pile Response - Kevin Franke From Theory to Practice: Performance-based Kinematic Pile Response - Kevin Franke Presentation Transcript

  • Kevin W. Franke, Ph.D., P.E.Assistant Professor, 2011-2012 EERI/FEMA NEHRP Graduate Fellow Department of Civil and Environmental Engineering Brigham Young University, Provo, Utah 2013 EERI Annual Meeting Seattle, WA USA February 14, 2013 Kevin W. Franke, 2011-2012 EERI/FEMA NEHRP Graduate Fellow Feb 14, 2013
  • Goals of our Research: Develop a PB procedure to compute kinematic pile response due to free-field lateral spread displacement  Incorporate empirical lateral spread models, but be flexible enough to utilize other methods if desired  Utilize commonly-used pile response software (e.g. LPILE) Revisit and develop five “forgotten” kinematic loading case histories from Costa Rica Make inferences based on comparisons between the PB results and observed kinematic pile response from the case histories. Kevin W. Franke, 2011-2012 EERI/FEMA NEHRP Graduate Fellow Feb 14, 2013
  • Lateral Spreading after Varnes (1978)(after Varnes (1978) Port in Port-au-prince, Haiti following 2010 EQ Kevin W. Franke, 2011-2012 EERI/FEMA NEHRP Graduate Fellow Feb 14, 2013
  • Lateral Spreading Down Slope Movement Kevin W. Franke, 2011-2012 EERI/FEMA NEHRP Graduate Fellow Feb 14, 2013
  • Performance-based Kinematic PileResponse Procedure  DV   G DV DM dG DM EDP dG EDP IM d  IM Intensity Measure – lateral spreading loading parameter, L (after Franke 2005, Kramer et al. 2007) Engineering Demand Parameter – lateral spreading displacement Damage Measure – kinematic pile response Kevin W. Franke, 2011-2012 EERI/FEMA NEHRP Graduate Fellow Feb 14, 2013
  • Performance-based Kinematic PileResponse ProcedureDevelop hazard curves for lateral spread displacement usingempirical models using Franke (2005) and Kramer et al. (2007)procedure. Ni d   P  DH  d | L i , S    L  i 1 Kevin W. Franke, 2011-2012 EERI/FEMA NEHRP Graduate Fellow Feb 14, 2013
  • Performance-based Kinematic PileResponse ProcedureGiven a lateral spread displacement vector, use a kinematic pileresponse model to compute mean pile response and tocharacterize uncertainty in soil/pile interaction Pile Displacement (m) Shear Force (kN) Bending Moment (kN-m) Curvature (rad) -0.5 0 0.5 1 1.5 2 2.5 3 -2000 -1000 0 1000 2000 -1000 0 1000 2000 -0.4 -0.2 0 0.2 01. Point estimate methods2. First order second 2 moment methods 4 Depth Below Pile Head (m)3. Monte Carlo methods 6 Pile response 8  R  R  P  R  R   1       10   R|DH    12 14 Kevin W. Franke, 2011-2012 EERI/FEMA NEHRP Graduate Fellow Feb 14, 2013
  • Performance-based Kinematic Pile Response ProcedureAt the depth of interest, compute the mean annual rate ofexceeding R  as: Lateral Displacement N DH Depth 1m at depth = 0 R   P  R  R | DH  D     H ,i i 1 Lateral Displacement Depth Could develop similar 2m at depth = 0 Mean Annual Rate of plots for bending Exceedance moment, shear force, Lateral Displacement or curvature! Depth 3m at depth = 0 1 2 3 4 Lateral Displacement at the Pile Head (m) Kevin W. Franke, 2011-2012 EERI/FEMA NEHRP Graduate Fellow Feb 14, 2013
  • Performance-based Kinematic Pile Response ProcedureBy performing across all depths of the pile, uniform hazardpile response profiles can be developed Kevin W. Franke, 2011-2012 EERI/FEMA NEHRP Graduate Fellow Feb 14, 2013
  • Costa Rica Limon Earthquake• April 22, 1991 – M7.6• Killed 53 people• Injured 193 people• Disrupted ~30% of highways in the Limon Province Kevin W. Franke, 2011-2012 EERI/FEMA NEHRP Graduate Fellow Feb 14, 2013
  • Costa Rica Case Histories Kevin W. Franke, 2011-2012 EERI/FEMA NEHRP Graduate Fellow Feb 14, 2013
  • Rio Cuba Bridge• Reinforced Concrete bridge• Constructed in the late 1960’s• 3-spans, each 22 meters in length• Each abutment supported by fifteen 14-inch square RC piles that are 14 meters in length• 30° skew at abutments• Approach embankments are approximately 6 meters high Kevin W. Franke, 2011-2012 EERI/FEMA NEHRP Graduate Fellow Feb 14, 2013
  • Rio Cuba Bridge• Bridge deck did not collapse, but “pinned” the abutments• Cracked piles are still exposed• Rotations still visible (8.5° at the east abutment)• All visible evidence of lateral spread is gone, but back-calculation suggests that soil displacements were approximately 0.35 meter Kevin W. Franke, 2011-2012 EERI/FEMA NEHRP Graduate Fellow Feb 14, 2013
  • Rio Cuba Bridge Lessons Learned• Deterministic empirical lateral spread models computed average displacement of 0.27 meter (within 31% of back- calculated displacement).• Bridge deck did not collapse, but “pinned” the abutments.• The bridge deck appears to govern the behavior of the kinematic pile response. Free (No Bridge Deck) Pinned (Bridge Deck) Kevin W. Franke, 2011-2012 EERI/FEMA NEHRP Graduate Fellow Feb 14, 2013
  • Rio Bananito Highway Bridge (Original Bridge)• Reinforced concrete bridge• Constructed in the 1971• 2-spans, each ~27 meters in length• South abutment supported by nine 14-inch square RC After Priestley et al (1991) piles that are 15 meters in length (Bridge Today)• 30° skew at abutments• Approach embankments are approximately 3 meters high Kevin W. Franke, 2011-2012 EERI/FEMA NEHRP Graduate Fellow Feb 14, 2013
  • Rio Bananito Highway Bridge• Bridge deck collapsed following massive soil deformations (3.5 - 5.1 meters)• Piles and abutment were rotated 14 degrees and translated 3.9 meters• Post-seismic slope stability analysis suggests this event was likely a flow failure• Eye-witness account reports that the deck stayed in place for approximately 1 minute; After Youd et al. (1992) after it collapsed, the entire abutment slid into the river Kevin W. Franke, 2011-2012 EERI/FEMA NEHRP Graduate Fellow Feb 14, 2013
  • RB Highway Bridge Lessons Learned• Deterministic empirical lateral spread models computed less than half of measured displacements.• Again, the importance of the bridge deck in determining pile response is demonstrated.• A deterministic 2-stage calculation successfully replicated the horizontal pile/abutment deformations at the south abutment. Kevin W. Franke, 2011-2012 EERI/FEMA NEHRP Graduate Fellow Feb 14, 2013
  • Rio Bananito Railway Bridge• Steel truss rail bridge• Constructed prior to 1890• single-span 48 meters in length• Each abutment supported by two 1.5m x 2.2m elliptical CISS caissons• Dynamic wave equation analysis of exposed caissons suggests they are 12 meters in length• Little to no approach embankments Kevin W. Franke, 2011-2012 EERI/FEMA NEHRP Graduate Fellow Feb 14, 2013
  • Rio Bananito Railway Bridge• Lateral spreading pushed all four caissons towards the river (between 0.5 to 5.7 meters, rotations of 26°- 37°) and unseated the bridge at both abutments.• Bridge tilted to the east 15 degrees, but amazingly did not collapse.• Lateral spread displacement of over 4 meters was measured in the free- field at the north abutment. Photos after Youd (1993)• Dynamic wave equation analysis indicated significant caisson damage at a depths between 8-9 meters Kevin W. Franke, 2011-2012 EERI/FEMA NEHRP Graduate Fellow Feb 14, 2013
  • RB Railway Bridge Lessons Learned (Deterministic) (Performance-Based)• Average empirical lateral spread displacement at the north abutment was 2.6 meters, which under- predicted observed displacements.• Traditional pile response methods using p-y analysis in LPILE reasonably replicated the observed pile response of a single caisson.• Maximum moment was computed to occur between depths of 8-9 meters.• PB analysis showed that the actual kinematic pile response corresponded to Tr=560 years. (AASHTO currently targets Tr=1,033 years). Kevin W. Franke, 2011-2012 EERI/FEMA NEHRP Graduate Fellow Feb 14, 2013
  • Rio Estrella Bridge• 3-span steel and pre- stressed concrete bridge that is 178m in length• Constructed in 1971• South abutment is supported by 2 bent-style pile caps, each founded on 24 H-piles• Surficial topography around the bridge is constantly changing due to the river and the “banana wars” Kevin W. Franke, 2011-2012 EERI/FEMA NEHRP Graduate Fellow Feb 14, 2013
  • Rio Estrella Bridge Courtesy of EERI• The two steel truss spans collapsed during earthquake shaking.• Significant liquefaction and lateral spread observed in the vicinity of the southern abutment. Up to 2 meters of lateral displacement was estimated.• The approach embankment to the Courtesy of LIS, Universidad de southern abutment experienced Costa Rica extensive localized, transverse slope stability failures.• Amazingly, the abutment itself was not moved despite the kinematic chaos around it. We wanted to find out why. Kevin W. Franke, 2011-2012 EERI/FEMA NEHRP Graduate Fellow Feb 14, 2013
  • Rio Estrella Bridge Lessons Learned• Empirical lateral spread models (No Water Film) (Water Film) significantly underpredicted (0.4m) the observed displacements at the southern abutment (~2m).• Our analysis suggests that the pinning effect of the piles was not sufficient alone to keep the foundation from moving.• The soil stratigraphy at the site supported the theory that a water film may have developed above the pile caps, thus isolating the pile caps from the bulk of the kinematic loading.• For similar scenarios, similar innovative foundation design might help reduce potential damage to foundations from kinematic loading. Kevin W. Franke, 2011-2012 EERI/FEMA NEHRP Graduate Fellow Feb 14, 2013
  • Conclusions1. A performance-based kinematic pile response procedure was successfully developed.  Based on empirical lateral spread displacement models  Soil-pile interaction can be computed with commonly-used software such as LPILE  Useful for evaluating the return period associated with various levels of kinematic pile response2. New lateral spread/kinematic pile response case histories from the 1991 Limon EQ in Costa Rica were brought to light.3. For these cases, empirical lateral spread models generally under-predicted the observed displacements. Kevin W. Franke, 2011-2012 EERI/FEMA NEHRP Graduate Fellow Feb 14, 2013
  • Conclusions4. For bridges, the presence of the bridge deck plays a major role in the kinematic response of the piles, even for simply-supported abutments.5. The development of a water film can isolate the majority of the lateral displacements to a relatively thin zone.6. For certain applications, placing the pile cap within or below the liquefiable layer may reduce foundation damage due to kinematic loading. Kevin W. Franke, 2011-2012 EERI/FEMA NEHRP Graduate Fellow Feb 14, 2013
  • Acknowledgements This study was funded by a grant from the US Geological Survey External Research Program (No. G10AP00047) The Costa Rica Ministry of Transportation Prof. Kyle Rollins (BYU) Prof. T. Leslie Youd (BYU) Prof. Steven Kramer (UW) EERI/FEMA My wife Ruby and our 5 beautiful children Kevin W. Franke, 2011-2012 EERI/FEMA NEHRP Graduate Fellow Feb 14, 2013
  • Thank you! Kevin W. Franke, Ph.D., P.E.Assistant Professor, 2011-2012 EERI/FEMA NEHRP Graduate Fellow Department of Civil and Environmental Engineering Brigham Young University, Provo, Utah 2013 EERI Annual Meeting Seattle, WA USA February 14, 2013 Kevin W. Franke, 2011-2012 EERI/FEMA NEHRP Graduate Fellow Feb 14, 2013