2-D Liquefaction Evaluation with Q4Mesh · evaluations of earth structures and soil deposits can...
Transcript of 2-D Liquefaction Evaluation with Q4Mesh · evaluations of earth structures and soil deposits can...
US Army Corpsof EngineersSacramento District
3 August 20053 August 2005 2005 Tri2005 Tri--Service ISCService ISC 11
2005 Tri-Service Infrastructure SystemsConference and Exhibition2005 Tri-Service Infrastructure SystemsConference and Exhibition
-David C. Serafini, M.S., P.E.US Army Corps of Engineers, Sacramento, CA
2-D Liquefaction Evaluationwith Q4Mesh
US Army Corpsof EngineersSacramento District
3 August 20053 August 2005 2005 Tri2005 Tri--Service ISCService ISC 22
Presentation OutlinePresentation Outline
� Liquefaction Evaluation Overview� Overview of Quad4m� Overview of Q4Mesh� Liquefaction Evaluation with Q4Mesh� Example Q4Mesh Liquefaction Model
� Liquefaction Evaluation Overview� Overview of Quad4m� Overview of Q4Mesh� Liquefaction Evaluation with Q4Mesh� Example Q4Mesh Liquefaction Model
US Army Corpsof EngineersSacramento District
3 August 20053 August 2005 2005 Tri2005 Tri--Service ISCService ISC 33
Liquefaction Evaluation OverviewLiquefaction Evaluation Overview
� Two-dimensional seismic response and liquefactionevaluations of earth structures and soil deposits canbe complex and time intensive
� Techniques available for their evaluation range fromsimplified models to advanced constitutive and non-linear models
� Two-dimensional seismic response and liquefactionevaluations of earth structures and soil deposits canbe complex and time intensive
� Techniques available for their evaluation range fromsimplified models to advanced constitutive and non-linear models
US Army Corpsof EngineersSacramento District
3 August 20053 August 2005 2005 Tri2005 Tri--Service ISCService ISC 44
Liquefaction Evaluation OverviewLiquefaction Evaluation Overview
� Simplified Models– Simplified Seed and Idriss procedures– 1-D equivalent linear SHAKE type analysis at multiple locations– Evaluations can be made quickly
� Advanced Models– Most accommodate the non-linear behavior of soils– Evaluations are more complex and time intensive
� Equivalent Linear Models– Can be used to approximate the actual nonlinear behavior of the soil– Quad4m (two-dimensional seismic response)
� Simplified Models– Simplified Seed and Idriss procedures– 1-D equivalent linear SHAKE type analysis at multiple locations– Evaluations can be made quickly
� Advanced Models– Most accommodate the non-linear behavior of soils– Evaluations are more complex and time intensive
� Equivalent Linear Models– Can be used to approximate the actual nonlinear behavior of the soil– Quad4m (two-dimensional seismic response)
US Army Corpsof EngineersSacramento District
3 August 20053 August 2005 2005 Tri2005 Tri--Service ISCService ISC 55
Overview of Quad4mOverview of Quad4m
� Quad4m (A Computer Program For EvaluatingThe Seismic Response Of Soil Structures)– U.C.Davis, 1993– by Martin Byrd Hudson, I.M.Idriss, and Mohsen
Beikae
� MODIFIED FROM QUAD4, 1973– by I.M. Idriss, J. Lysmer, R. Hwang and H. Bolton
Seed
� Quad4m (A Computer Program For EvaluatingThe Seismic Response Of Soil Structures)– U.C.Davis, 1993– by Martin Byrd Hudson, I.M.Idriss, and Mohsen
Beikae
� MODIFIED FROM QUAD4, 1973– by I.M. Idriss, J. Lysmer, R. Hwang and H. Bolton
Seed
US Army Corpsof EngineersSacramento District
3 August 20053 August 2005 2005 Tri2005 Tri--Service ISCService ISC 66
Overview of Quad4mOverview of Quad4m
� The Quad4m analysis numerically models a continuumwith a finite number of elements interconnected attheir common nodes
� The analysis is done exclusively in the time domain,and the response of the soil deposit follows the sameapproximation of nonlinear hysteretic manner that isconventional SHAKE (1-D) analysis when subject toloading
� The Quad4m analysis numerically models a continuumwith a finite number of elements interconnected attheir common nodes
� The analysis is done exclusively in the time domain,and the response of the soil deposit follows the sameapproximation of nonlinear hysteretic manner that isconventional SHAKE (1-D) analysis when subject toloading
US Army Corpsof EngineersSacramento District
3 August 20053 August 2005 2005 Tri2005 Tri--Service ISCService ISC 77
Overview of Quad4mOverview of Quad4m
� Direct numerical integration by the software is usedto solve an equation of motion for the finite elementmesh to determine the developed:
– Peak Element Shear Stresses (sig-xy, τmax)– Peak Element Shearing Strains (eps, γmax)– Peak Element Principle Stresses (sig-x, sig-y)– Peak Nodal Accelerations (amax)
� Direct numerical integration by the software is usedto solve an equation of motion for the finite elementmesh to determine the developed:
– Peak Element Shear Stresses (sig-xy, τmax)– Peak Element Shearing Strains (eps, γmax)– Peak Element Principle Stresses (sig-x, sig-y)– Peak Nodal Accelerations (amax)
US Army Corpsof EngineersSacramento District
3 August 20053 August 2005 2005 Tri2005 Tri--Service ISCService ISC 88
Overview of Q4MeshOverview of Q4Mesh
� The Q4Mesh program is a modification of theWinMesh program to create and analyze Quad4mdata
� Q4mesh was developed by ERDC (EngineeringResearch and Development Center) at WES(Waterways Experimental Station) with someassistance provided from the USACE SacramentoDistrict
� The Q4Mesh program is a modification of theWinMesh program to create and analyze Quad4mdata
� Q4mesh was developed by ERDC (EngineeringResearch and Development Center) at WES(Waterways Experimental Station) with someassistance provided from the USACE SacramentoDistrict
US Army Corpsof EngineersSacramento District
3 August 20053 August 2005 2005 Tri2005 Tri--Service ISCService ISC 99
Overview of Q4MeshOverview of Q4Mesh
� Q4Mesh can be used to:
– Create the Quad4m finite element mesh
– Interpret the output files from Quad4m and twoadditional user files to conduct a liquefactionevaluation
� Q4Mesh can be used to:
– Create the Quad4m finite element mesh
– Interpret the output files from Quad4m and twoadditional user files to conduct a liquefactionevaluation
US Army Corpsof EngineersSacramento District
3 August 20053 August 2005 2005 Tri2005 Tri--Service ISCService ISC 1010
Overview of Q4MeshOverview of Q4Mesh
� Q4Mesh– (Main Screen)
� Q4Mesh– (Main Screen)
US Army Corpsof EngineersSacramento District
3 August 20053 August 2005 2005 Tri2005 Tri--Service ISCService ISC 1111
Overview of Q4MeshOverview of Q4Mesh
Additional Input Files for Q4MeshAdditional Input Files for Q4Mesh
1)
3)
4)5)
2)
Blowcount FileSurface, Phreatic, and Earthquake File
US Army Corpsof EngineersSacramento District
3 August 20053 August 2005 2005 Tri2005 Tri--Service ISCService ISC 1212
Overview of Q4MeshOverview of Q4Mesh
� Basic Liquefaction Procedure Equation
CSR (Cyclic Stress Ratio)CRR (Cyclic Resistance Ratio)Kσ (Stress CorrectionKα (Sloping Ground Correction)MSF (Magnitude Scaling Factor)
� Basic Liquefaction Procedure Equation
CSR (Cyclic Stress Ratio)CRR (Cyclic Resistance Ratio)Kσ (Stress CorrectionKα (Sloping Ground Correction)MSF (Magnitude Scaling Factor)
US Army Corpsof EngineersSacramento District
3 August 20053 August 2005 2005 Tri2005 Tri--Service ISCService ISC 1313
Example Q4Mesh Liquefaction ModelExample Q4Mesh Liquefaction Model
� Cyclic Resistance Ratio, CRR (Vs1 Data)� Cyclic Resistance Ratio, CRR (Vs1 Data)
US Army Corpsof EngineersSacramento District
3 August 20053 August 2005 2005 Tri2005 Tri--Service ISCService ISC 1414
Example Q4Mesh Liquefaction ModelExample Q4Mesh Liquefaction Model
� Cyclic Resistance Ratio, CRR (N1,60 Data)� Cyclic Resistance Ratio, CRR (N1,60 Data)
US Army Corpsof EngineersSacramento District
3 August 20053 August 2005 2005 Tri2005 Tri--Service ISCService ISC 1515
Example Q4Mesh Liquefaction ModelExample Q4Mesh Liquefaction Model
� Stress Correction Factor, Kσ� Stress Correction Factor, Kσ
DefaultKα=1.0
US Army Corpsof EngineersSacramento District
3 August 20053 August 2005 2005 Tri2005 Tri--Service ISCService ISC 1616
Example Q4Mesh Liquefaction ModelExample Q4Mesh Liquefaction Model
� Magnitude Scaling Factor (MSF)� Magnitude Scaling Factor (MSF)
US Army Corpsof EngineersSacramento District
3 August 20053 August 2005 2005 Tri2005 Tri--Service ISCService ISC 1717
Example Q4Mesh Liquefaction ModelExample Q4Mesh Liquefaction Model
Embankment Dam on a LiquefiableFoundation (EDOLF)
Embankment Dam on a LiquefiableFoundation (EDOLF)
US Army Corpsof EngineersSacramento District
3 August 20053 August 2005 2005 Tri2005 Tri--Service ISCService ISC 1818
Example Q4Mesh Liquefaction ModelExample Q4Mesh Liquefaction Model
� Finite Element Mesh� Finite Element Mesh
US Army Corpsof EngineersSacramento District
3 August 20053 August 2005 2005 Tri2005 Tri--Service ISCService ISC 1919
Example Q4Mesh Liquefaction ModelExample Q4Mesh Liquefaction Model
� Material Properties� Material Properties
US Army Corpsof EngineersSacramento District
3 August 20053 August 2005 2005 Tri2005 Tri--Service ISCService ISC 2020
Example Q4Mesh Liquefaction ModelExample Q4Mesh Liquefaction Model
� Input Earthquake Record– IMPERIAL VALLEY EARTHQUAKE, CA; OCT 15, 1979– Mw=6.75 at 22km– Amax=0.28g– Filtered Record Low-Pass=20hz– Bracketed Duration ~22 seconds– "ROCK OUTCROP MOTION"
� Input Earthquake Record– IMPERIAL VALLEY EARTHQUAKE, CA; OCT 15, 1979– Mw=6.75 at 22km– Amax=0.28g– Filtered Record Low-Pass=20hz– Bracketed Duration ~22 seconds– "ROCK OUTCROP MOTION"
US Army Corpsof EngineersSacramento District
3 August 20053 August 2005 2005 Tri2005 Tri--Service ISCService ISC 2121
Example Q4Mesh Liquefaction ModelExample Q4Mesh Liquefaction Model
� Input Shear Wave Velocities� Input Shear Wave Velocities
Input Shear Wave Velocity Profile, Vs (ft/s)
US Army Corpsof EngineersSacramento District
3 August 20053 August 2005 2005 Tri2005 Tri--Service ISCService ISC 2222
Example Q4Mesh Liquefaction ModelExample Q4Mesh Liquefaction Model
Quad4m Analysis ResultsQuad4m Analysis Results
US Army Corpsof EngineersSacramento District
3 August 20053 August 2005 2005 Tri2005 Tri--Service ISCService ISC 2323
Example Q4Mesh Liquefaction ModelExample Q4Mesh Liquefaction Model
� Peak Nodal Horizontal Acceleration (g)� Peak Nodal Horizontal Acceleration (g)
Peak Horizontal Acceleration (g)
Time to Peak Horizontal Acceleration (seconds)
US Army Corpsof EngineersSacramento District
3 August 20053 August 2005 2005 Tri2005 Tri--Service ISCService ISC 2424
Example Q4Mesh Liquefaction ModelExample Q4Mesh Liquefaction Model
� Peak Element Induced Shear Stress and Strain� Peak Element Induced Shear Stress and StrainPeak Shear Stress (psf)
Peak Shear Strain (%)
US Army Corpsof EngineersSacramento District
3 August 20053 August 2005 2005 Tri2005 Tri--Service ISCService ISC 2525
Example Q4Mesh Liquefaction ModelExample Q4Mesh Liquefaction Model
Q4Mesh Analysis and ResultsQ4Mesh Analysis and Results
US Army Corpsof EngineersSacramento District
3 August 20053 August 2005 2005 Tri2005 Tri--Service ISCService ISC 2626
Example ModelExample Model
Given: γsat =135pcf, γmoist =130pcf for all elements
Total Stress Profile (psf)
Effective Stress Profile (psf)
US Army Corpsof EngineersSacramento District
3 August 20053 August 2005 2005 Tri2005 Tri--Service ISCService ISC 2727
Example Q4Mesh Liquefaction ModelExample Q4Mesh Liquefaction Model
� Normalized Shear Wave Velocities� Normalized Shear Wave Velocities
Normalized Shear Wave Velocity Profile, Vs1 (ft/s)
US Army Corpsof EngineersSacramento District
3 August 20053 August 2005 2005 Tri2005 Tri--Service ISCService ISC 2828
Example Q4Mesh Liquefaction ModelExample Q4Mesh Liquefaction Model
� Input Blowcount Data, (N1)60 (blows/ft)� Input Blowcount Data, (N1)60 (blows/ft)
US Army Corpsof EngineersSacramento District
3 August 20053 August 2005 2005 Tri2005 Tri--Service ISCService ISC 2929
Example Q4Mesh Liquefaction ModelExample Q4Mesh Liquefaction Model
Cyclic Resistance Ratio CRR– Vs1 Values
– (N1)60 Blowcount Values
Cyclic Resistance Ratio CRR– Vs1 Values
– (N1)60 Blowcount Values
US Army Corpsof EngineersSacramento District
3 August 20053 August 2005 2005 Tri2005 Tri--Service ISCService ISC 3030
Example Q4Mesh Liquefaction ModelExample Q4Mesh Liquefaction Model
� Cyclic Resistance Ratio, CRR– (Calculated from the Vs1 Values)
� Cyclic Resistance Ratio, CRR– (Calculated from the Vs1 Values)
NCEER Workshop
Andrus and Stokoe (1997)
US Army Corpsof EngineersSacramento District
3 August 20053 August 2005 2005 Tri2005 Tri--Service ISCService ISC 3131
Example Q4Mesh Liquefaction ModelExample Q4Mesh Liquefaction Model
� Cyclic Resistance Ratio, CRR– (Calculated from the (N1)60 Values)
� Cyclic Resistance Ratio, CRR– (Calculated from the (N1)60 Values)
ICSDEE and ICEGE Conference
Idriss and Boulanger (2004)
US Army Corpsof EngineersSacramento District
3 August 20053 August 2005 2005 Tri2005 Tri--Service ISCService ISC 3232
Example Q4Mesh Liquefaction ModelExample Q4Mesh Liquefaction Model
Cyclic Stress Ratio CSR– Peak Element Stresses
– Seed and Idriss Simplified Procedure
Cyclic Stress Ratio CSR– Peak Element Stresses
– Seed and Idriss Simplified Procedure
US Army Corpsof EngineersSacramento District
3 August 20053 August 2005 2005 Tri2005 Tri--Service ISCService ISC 3333
Example Q4Mesh Liquefaction ModelExample Q4Mesh Liquefaction Model
� Cyclic Stress Ratio, CSR– (Calculated from Quad4m Peak Induced Shear Stresses)
� Cyclic Stress Ratio, CSR– (Calculated from Quad4m Peak Induced Shear Stresses)
US Army Corpsof EngineersSacramento District
3 August 20053 August 2005 2005 Tri2005 Tri--Service ISCService ISC 3434
Example Q4Mesh Liquefaction ModelExample Q4Mesh Liquefaction Model
� Cyclic Stress Ratio, CSR– (Calculated from Simplified Procedure)
� Cyclic Stress Ratio, CSR– (Calculated from Simplified Procedure)
CSR = (CSR = (ττavav//σσ’’vovo) = 0.65() = 0.65(aamaxmax/g)(/g)(σσvovo//σσ’’vovo)rd)rd
Parameters as Defined byParameters as Defined by YoudYoud and Idriss 2001and Idriss 2001
US Army Corpsof EngineersSacramento District
3 August 20053 August 2005 2005 Tri2005 Tri--Service ISCService ISC 3535
Example Q4Mesh Liquefaction ModelExample Q4Mesh Liquefaction Model
� Stress Correction Factor, Kσ� Stress Correction Factor, Kσ
ICSDEE and ICEGE Conference
Idriss and Boulanger (2004)
US Army Corpsof EngineersSacramento District
3 August 20053 August 2005 2005 Tri2005 Tri--Service ISCService ISC 3636
Example Q4Mesh Liquefaction ModelExample Q4Mesh Liquefaction Model� Liquefaction Potential Factor of Safety, Vs1 Data� Liquefaction Potential Factor of Safety, Vs1 Data
(CSR-Quad4m, CRR-Vs1) with Kα=1.0
(CSR-Simplified Procedure, CRR-Vs1) with Kα=1.0
US Army Corpsof EngineersSacramento District
3 August 20053 August 2005 2005 Tri2005 Tri--Service ISCService ISC 3737
Example Q4Mesh Liquefaction ModelExample Q4Mesh Liquefaction Model� Liquefaction Potential Factor of Safety, (N1)60 Data� Liquefaction Potential Factor of Safety, (N1)60 Data
(CSR-Quad4m, CRR-(N1)60 with Kα=1.0
(CSR-Simplified Procedure, CRR-(N1)60 with Kα=1.0
US Army Corpsof EngineersSacramento District
3 August 20053 August 2005 2005 Tri2005 Tri--Service ISCService ISC 3838
Concluding RemarksConcluding Remarks
� Q4Mesh enables the ability to conduct 2-Dliquefaction potential evaluations from Quad4m outputdata
� Quad4m and Q4Mesh can be used as a first stepevaluation before more advanced models areimplemented
� User experience and correct model generation isimportant when evaluating the Quad4m output files
� Q4Mesh enables the ability to conduct 2-Dliquefaction potential evaluations from Quad4m outputdata
� Quad4m and Q4Mesh can be used as a first stepevaluation before more advanced models areimplemented
� User experience and correct model generation isimportant when evaluating the Quad4m output files
US Army Corpsof EngineersSacramento District
3 August 20053 August 2005 2005 Tri2005 Tri--Service ISCService ISC 3939
ReferencesReferences� Idriss, I. M., and Boulanger, R. W. (2004). "Semi-empirical procedures for
evaluating liquefaction potential during earthquakes." Proc., 11thInternational Conference on Soil Dynamics and Earthquake Engineering, and3rd International Conference on Earthquake Geotechnical Engineering, D.Doolin et al., eds., Stallion Press, Vol. 1, 32-56.
� Boulanger, R. W. and Idriss, I. M. (2004). "State normalization of penetrationresistances and the effect of overburden stress on liquefaction resistance."Proc., 11th International Conference on Soil Dynamics and EarthquakeEngineering, and 3rd International Conference on Earthquake GeotechnicalEngineering, D. Doolin et al., eds., Stallion Press, Vol. 2, 484-491.
� Youd, T. L. and Idriss, I. M. (2001). "Liquefaction resistance of soils:summary report from the 1996 NCEER and 1998 NCEER/NSF Workshops onEvaluation of Liquefaction Resistance of Soils," Journal of Geotechnical andGeoenvironmental Engineering, ASCE, Vol. 127, No. 4, pp. 297-313.
� Idriss, I. M., and Boulanger, R. W. (2004). "Semi-empirical procedures forevaluating liquefaction potential during earthquakes." Proc., 11thInternational Conference on Soil Dynamics and Earthquake Engineering, and3rd International Conference on Earthquake Geotechnical Engineering, D.Doolin et al., eds., Stallion Press, Vol. 1, 32-56.
� Boulanger, R. W. and Idriss, I. M. (2004). "State normalization of penetrationresistances and the effect of overburden stress on liquefaction resistance."Proc., 11th International Conference on Soil Dynamics and EarthquakeEngineering, and 3rd International Conference on Earthquake GeotechnicalEngineering, D. Doolin et al., eds., Stallion Press, Vol. 2, 484-491.
� Youd, T. L. and Idriss, I. M. (2001). "Liquefaction resistance of soils:summary report from the 1996 NCEER and 1998 NCEER/NSF Workshops onEvaluation of Liquefaction Resistance of Soils," Journal of Geotechnical andGeoenvironmental Engineering, ASCE, Vol. 127, No. 4, pp. 297-313.
US Army Corpsof EngineersSacramento District
3 August 20053 August 2005 2005 Tri2005 Tri--Service ISCService ISC 4040
Thank you!
2005 Tri-Service Infrastructure SystemsConference and Exhibition2005 Tri-Service Infrastructure SystemsConference and Exhibition
US Army Corpsof EngineersSacramento District
3 August 20053 August 2005 2005 Tri2005 Tri--Service ISCService ISC 4141
David C. Serafini, M.S., P.E.US Army Corps of Engineers, Sacramento, CA1325 J. StreetSacramento, CA 95814(916) [email protected]
Contact InformationContact Information