DEEPSOIL - PowerPoint Presentati by chenshu

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									        Youssef Hashash
          Associate Professor

  In collaboration with Duhee Park
    Post-Doctoral Research Assistant

University of Illinois at Urbana-Champaign

      PEER 2G02 First Meeting
          September 21, 2004
DEEPSOIL

   1-D Site response analysis code

   Nonlinear / Equivalent linear analysis

   User interface




                                  2          Hashash and Park (2004)
Motivation for Development
   Thick soil deposits such as those encountered in the
    Mississippi Embayment in Mid-America

   Sponsored in part by Mid-America Earthquake Center

   References:
       Park, D. and Y. M. A. Hashash (2004). "Soil damping formulation in nonlinear time
        domain site response analysis." Journal of Earthquake Engineering 8(2): 249-274.
       Hashash, Y. M. A., and Park, D. (2002). "Viscous damping formulation and high
        frequency motion propagation in nonlinear site response analysis." Soil Dynamics and
        Earthquake Engineering, 22(7), pp. 611-624.
       Hashash, Y. M. A., and Park, D. (2001). "Non-linear one-dimensional seismic ground
        motion propagation in the Mississippi embayment." Engineering Geology, 62(1-3), 185-
        206.
       Park, D. (2003). ESTIMATION OF NON-LINEAR SEISMIC SITE EFFECTS FOR DEEP
        DEPOSITS OF THE MISSISSIPPI EMBAYMENT. Department of Civil and
        Environmental Engineering. Urbana, University of Illinois at Urbana-Champaign: 337 p.



                                                              3               Hashash and Park (2004)
Outline
    Features of DEEPSOIL
        Nonlinear
          Numerical Model

          User Interface



        Equivalent Linear
          Numerical Model

          User Interface



        Additional Features of the User Interface




                                             4       Hashash and Park (2004)
Nonlinear (NL) Features

   Soil Model
   Viscous Damping Formulation
   Dynamic Integration Scheme
   Increased Numerical Accuracy
   User Interface




                               5   Hashash and Park (2004)
NL Feature – Soil Model
   Extended Modified Hyperbolic Model
       Based on Modified Hyperbolic Model (Matasovic, 1993)
       Confining pressure dependent

                                                                                    G         G
           Modified Hyperbolic Model                                                  sec1        sec2
                                                                     

            Gm o                 Gm o
                      s
                                           s
                                                                 
                                                                 

              Gm o                                Initial
        1  
                           1   
                                      
                                                       Loading
              mo                    r              Curve
                                                                                            
                                                Backbone                          Subsequent
                                      b
                   '            
                                                Curve                    Lo ading & Unloading Curves

           r  a 
                  
                                  
                                  
                   ref           



                                                           6                       Hashash and Park (2004)
                                              0.9

                                              0.8




NL Feature – Soil Model
                                              0.7

                                              0.6
                                                  1
                                              0.5
                                              1
                                              0.9
                                               0.4
                                              0.8
                                               0.3                                                                                                                 8
                                            0.9 0.0001 Laird & Stoke (Measured)
    G / Gmax                                  0.7
                                                                         0.001
                                                                                   Confining Pressuresur e D ependent Mode l
                                                                                     N on-Linear P res
                                                                                                                               0.01                      0.1

                                                                                                                                                                   7
 & Confinement                              0.8
                                              0.6                                    27.6 kP a
                                                                                     55.2 kP a                                                                      6
                                              0.5                                    110 kP a                                                                  5




                                      max
                                            0.7                                      221 kP a
                                                                                                                                                     3         4




                        G/G
                   b                          0.4                                    442 kP a

        '                                0.6                                      883 kP a


r  a        
                                              0.3                                    1776 kP a                                                       10.1 2
                                                0.0001                                            0.001                        0.01

             
                                            0.5            Non-Linear Pressure Dependent Model


        ref   
                                                           27.6 kPa
                                                     1=27.6 kPa 2=55.2 kPa 3=110 kPa 4=221 kPa
                                            0.4            55.2 kPa
                                                     5=442 kPa kPa
                                                           110 6=883 kPa 7=1776 kPa 8=10 MPa
                                                           221 kPa
                                            0.3            442 kPa
                                              0.0001       883 kPa
                                                                           0.001 Shear Strain,                                   0.01                              0.1
                                                           1776 kPa
                                                            0
  Damping                                   0.12      Confining Pressure (kPa)

                                                                                  2000
& Confinement                                0.1
                       Damping Ratio (-)




                                                                                  4000
                                            0.08
                                                                                  6000

      c                                     0.06                                                       Laird & Stokoe
                                                                                                                                             1       3

 
                                                                                  8000                 Proposed                                  2             4   5
                                                                                                       Equation



     '
                                            0.04                                                                                                                   6
         d                                                                       10000
                                                                                     0.1      Damping Ratio (%)          1
                                                                                                                                                                   7
                                                                                              at zero shear strain
                                            0.02
                                                                                                                                                                   8
                                               0
                                               0.0001                                                 0.001 Shear Strain,  0.01                                    0.1

                                                                                                                     7                       Hashash and Park (2004)
NL Feature– Viscous Damping Formulation
                     Viscous damping formulation [C]
   Simplified Rayleigh damping formulation
   Full Rayleigh damping formulation
            Conventional Selection of Frequencies/Modes (CRF)
            Proposed Selection (RF)
   Extended Rayleigh damping formulation (ERF)



   M u K u Cu  M I ug
                                      


            C   R M    R K 
                                                  8             Hashash and Park (2004)
                  Feature 2 – Viscous Damping Formulation

                    2
                                             Simplified Rayleigh damping
    Effective damping ratio, (%)




                                                                                              Target
                    1                                                                         Damping
                                                                                              Ratio




                    0
                                     f


                                                                       C    R M    R K 
                                         m                       Frequency (Hz)




Fig 3-1 Page 68                                                                   9      Hashash and Park (2004)
                       Feature 2 – Viscous Damping Formulation
                2
                                              Full Rayleigh damping
                                              (CRF & RF)
Effective damping ratio, (%)




                                                                                                      Target
                1                                                                                     Damping
                                                                                                      Ratio


                                         Simplified RF

                0
                                 f                        f
                                     m                        n
                                    Frequency (Hz)
             Selection of frequencies/modes for Full Rayleigh damping formulation
             CRF (Conventional RF) : fm = 1st mode of soil column, fn=dominant period of input motion
             RF (Proposed RF) : fm and fn chosen from transfer function of soil column and frequency content of
                                                         input motion  An iterative process

                                                                                               10   Hashash and Park (2004)
                                 NL Feature– Viscous Damping Formulation
                2
                                               Extended Rayleigh
                                               damping (ERF)
Effective damping ratio, (%)




                                          Simplified RF                 Full RF
                                                                                               Target
                1                                                                              Damping
                                                                                               Ratio




                0
                                  f                  f                        f   f
                                      m                  n                    o       p
                                                             Frequency (Hz)




                                                                                  11      Hashash and Park (2004)
    Numerical Implementation
                                   m1/2
 Layer                                            Layer Properties
                                   k1,c1     h1
   1       G1,1                                  G : shear modulus
                                                  : density
   2       G2,2                   k2,c2     h2   Vs: shear wave velocity
                                                  h : thickness                  Cyclic soil response
mi=i.hi                                          Equivalent Lumped              model
                                                  Mass Model
                                                  k: stiffness
   i       Gi,i                                  c: viscous damping
                                   mn/2
   n       Gn,n     CE=nVSE      kn,cn     hn

           GE,E                                  Elastic Rock Base
                                                                            Input ground motion
                   Multi-degree of freedom
                   lumped parameter model



                                                                            12            Hashash and Park (2004)
Nonlinear (NL) Integration Scheme
      M u K u Cu  M I ug
                                         

     Newmark Beta Method

       u i 1  u i  1   t u i  t u i 1
                                           
                                 
       u i 1  u i  t u i  0.5   t  u i   t  u i 1
                                                 2
                                                              2
                                                                  
      (Average acceleration method: =1/4, =1/2
       Implicit Method

       Unconditionally stable

       No numerical damping


                                                    13        Hashash and Park (2004)
                            NL Feature – Viscous Damping Formulation
                                                                 8
                                                                      (a)
                                   Fourier spectrum ratio (-)
Fourier Amplitude (g sec)




                                                                 6


                                                                 4
                                                                                                                                       RF – Conventional Approach
                                                                 2


                                                                 0
                                                                 5
                                                                                                                                           Use first mode of soil column and
                            Effective damping ratio,  (%)




                                                                      (b)
                                                                 4
                                                                                                                                            a higher mode or predominant
                                                                                                                                            period of ground motion
                                                                 3

                                                                 2

                                                                 1
                                                                                             Target damping ratio, = 1.8%
                                                                 0
                                                                            10                     1                          0.1
                                                                                  Frequency (Hz)
                                                                0.4
                                                                      (c)                               Frequency domain
                                   Spectral acceleration (g)




                                                                                                        solution
                                                                                                        CRF (1.1, 4 Hz
                                                                                                        = Mode: 1, 2)
                                                                0.2




                                                                 0
                                                                            0.1                    1                          10
                                                                                   Period (sec)




                                                                                                                                                       14             Hashash and Park (2004)
                            NL Feature – Viscous Damping Formulation
                                                                 8
                                                                      (a)
                                   Fourier spectrum ratio (-)
Fourier Amplitude (g sec)




                                                                 6


                                                                 4


                                                                 2
                                                                                                                                       RF/ERF
                                                                 0
                                                                 5
                                                                                                                                        Proposed Guideline
                            Effective damping ratio,  (%)




                                                                      (b)
                                                                 4                                                                         Use iterative procedure to
                                                                 3                                                                          obtain best match with
                                                                 2                                                                          frequency domain solution
                                                                 1
                                                                                             Target damping ratio, = 1.8%
                                                                                                                                           Dependent on soil column
                                                                 0
                                                                            10                     1                          0.1
                                                                0.4
                                                                                  Frequency (Hz)
                                                                                                                                           Dependent on input motion
                                                                      (c)                               Frequency domain
                                   Spectral acceleration (g)




                                                                                                        solution
                                                                                                        CRF (1.1, 4 Hz
                                                                                                        = Mode: 1, 2)
                                                                0.2
                                                                                                        RF (2, 10 Hz
                                                                                                        = Mode: 2, 5)
                                                                                                                                           ERF: Computationally
                                                                                                        ERF (2, 10, 35, 45 Hz
                                                                                                        = Mode: 2, 5, 16, 21)               expensive
                                                                 0
                                                                            0.1                    1                          10
                                                                                   Period (sec)




                                                                                                                                               15         Hashash and Park (2004)
    NL Feature – Viscous Damping Formulation
   Variable [C] Matrix
       Updates stiffness in the RF                            C   R M    R K 
        formulation
                                             1
                                                                            1000 m column
          Fourier Amplitude (g sec)




                                         0.1                                M=7, R=20km

                                        0.01

                                       0.001
                                                      Updated [C] matrix
                                      0.0001
                                                      Constant [C] matrix
                                             -5
                                        10
                                                  1                 10
                                                         Frequency (Hz)

                                                                       16            Hashash and Park (2004)
                            NL Feature – Increased Numerical Accuracy
                                   Fixed Sub-incrementation Scheme: Independent of strain level
                                   Flexible Sub-incrementation Scheme: depends on strain level




                                                                             Number of Incremental Solution Steps
                                                                                                                    30,000
                                       N = 1 Fixed




                                                                                                                                                                                                                         Flexible Time Increments, Max.
                                                                                                                                                                                        Flexible Time Increments, Max.
                                       N = 5 Fixed




                                                                                                                                                                                                                         Shear Strain Increment=0.05 %
                                                                                                                                                                                        Shear Strain Increment=0.01 %
                                                                                                                                  Number of Substeps, N=1
                            3           = 0.01% Flexible                                                          25,000
Spectral Acceleration (g)




                                                                                                                                  Fixed Time Increments
                                         max
                                        = 0.05% Flexible




                                                                                                                                                            Number of Substeps, N=5
                                         max
                                                                                                                    20,000




                                                                                                                                                            Fixed Time Increments
                            2
                                                                                                                    15,000

                                                                                                                    10,000

                                                             1000 m Column                                           5,000
                    1
                  0.9
                     0.1                                           1                                                    0
                                                Period (sec)
                                Input Motion
                                Station JMA NS Kobe Earthquake, PGA = 0.82g

                                                                                                                             17                                                       Hashash and Park (2004)
NL User Interface – Input Soil Profile




                                 18      Hashash and Park (2004)
NL User Interface – Input Soil Profile




                                 19      Hashash and Park (2004)
NL User Interface – Soil Model Parameter Selection




                                20       Hashash and Park (2004)
NL User Interface – Viscous Damping Formulation



                                      300 m
                                      ME Profile

                                      M=8,R=32km Motion




                                21         Hashash and Park (2004)
NL User Interface – Viscous Damping Formulation




                                22       Hashash and Park (2004)
NL User Interface – Viscous Damping Formulation




                              23      Hashash and Park (2004)
NL User Interface – Viscous Damping Formulation




                              24      Hashash and Park (2004)
NL User Interface – Numerical Accuracy Control




                               25      Hashash and Park (2004)
NL User Interface – Output




                             26   Hashash and Park (2004)
Equivalent linear (EQL) Features
    3 Types of Complex shear modulus
        Frequency independent (Kramer, 1996)

          G*  G1  2i 
         Frequency dependent (Udaka, 1975)

                                             
     


         G*  G 1  2 2  2i 1   2
        Simplified (Kramer, 1996)

                   
         G*  G 1    2i
                          2
                                     
    No limitation on
        number of layers
        number of materials
        number of motion data points
                                         27       Hashash and Park (2004)
EQL Features




               (SHAKE, use with care)




                                        28   Hashash and Park (2004)
Additional Features




                      29   Hashash and Park (2004)
Verification of DEEPSOIL
Loma Prieta Earthquake, M = 7.1, October 19, 1989
-Significance of viscous damping in DEEPSOIL (Strong Motion & non-linear material)
-Soil column: ~88 m




                                                    30             Hashash and Park (2004)
    Verification of DEEPSOIL
                            0.8

                                                                          E-W
Spectral acceleration (g)




                            0.4




                             0
                                  0            1                   2
                                                                   2                                        3
                                                                                                            3
                                                     Period (sec)
                                      Yerba Buena Recording (Input)
                                      Treasure Island (Recorded motion)                                     0.4
                                      Conventional Nonlinear analysis
                                                                                                                                                         N-S
                                                                                Spectral acceleration (g)
                                      (Simplified Rayleigh Damping)
                                      DEEPSOIL
                                      (Full Rayleigh Damping)

                                                                                                            0.2




                                                                                                                0
                                                                                                                    0        1                  2                 3
                                                                                                                                                                  3
                                                                                                                                 Period (sec)

                                                                                                                        31                          Hashash and Park (2004)
Nonlinear Soil Model Parameters

    No Fixed Parameter
    Selected to match various reference
     dynamic curves (G/Gmax and
     damping curves)




                                 32        Hashash and Park (2004)
                           NL Soil Model Parameters – Mississippi Embayment (ME)
                       1

                     0.9                                                              8
                                                                                      7
                     0.8
                                                                                       6
                                                                                  5                                  ME study
               max




                     0.7
                                                                              3   4
 G/G




                     0.6                                                                                       ME               EPRI
                                                                              1   2
                     0.5
                                                                                                              1.4              0.85
                     0.4                                                                               s       0.8              0.9
                     0.3                                                                           (a)
                       0.0001        0.001 Shear Strain,  0.01                        0.1 Reference
                                                                                                strain @
                     0.12                                                                          ’ref      0.163             0.07

                      0.1                                                                             ’ref   0.18              0.18
Damping Ratio (-)




                                                                                                       b      0.63              0.4
                     0.08

                     0.06                                             1       3
                                                                          2       4   5
                     0.04                                                             6                c        Varies with depth
                                                                                      7                d        0                0
                     0.02
                                                                                      8
                       0
                       0.0001        0.001 Shear Strain,  0.01                        0.1


                                                                                                 33             Hashash and Park (2004)
    NL Soil Model Parameters - EPRI
              1.2


              1.0
                                                                                                  ME study
              0.8
G/Gmax




                                                                                           ME                EPRI
              0.6

                                                                                          1.4               0.85
              0.4
                                                                                   s       0.8               0.9
              0.2                                                               (a)
                                                                             Reference
               0.0                                                               strain
              35.0                                                                 @
                           EPRI (0-20ft)
                                                                                  ’ref   0.163              0.07
                           EPRI (21-50ft)
              30.0
                           EPRI (51-120ft)                                        ’ref   0.18               0.18
                           EPRI (120-250ft)
              25.0                                                                 b      0.63               0.4
                           EPRI (251-500ft)
Damping (%)




                           EPRI (501-600ft)
              20.0
                           DEEPSOIL (0-20ft)
                           DEEPSOIL (21-50ft)
              15.0
                           DEEPSOIL (51-120ft)
                                                                                   c        Varies with depth
                           DEEPSOIL (121-250ft)
              10.0                                                                          0                 0
                           DEEPSOIL (251-500ft)                                    d
                           DEEPSOIL (501-600ft)
               5.0

               0.0
                    0.00             0.00            0.01      0.10   1.00
                                                  Strain (%)

                                                                             34                 Hashash and Park (2004)
NL Soil Model Parameters-Treasure Island
                1.2


                 1


                0.8
G/Gmax




                                                                                    Treasure Island
                0.6

                          Deepsoil Young Bay                                                   Old
                                                                                    Young
                0.4                                                                            Bay
                          Deepsoil Old Bay Mud                                     Bay Mud
                                                                                               Mud
                          Young Bay Mud
                0.2                                                                0.8        0.9
                          Old Bay Mud
                                                                           s        0.8        0.7
                 0
                30                                                        (a)
                                                                        Referenc
                25                                                      e strain
                                                                         @ ’ref    0.17      0.065
                20
  Damping (%)




                                                                          ’ref     N/A        N/A

                15                                                         b        0.0        0.0

                10

                 5                                                         c        1.5        1.5
                                                                           d          0        0.0
                 0
                 0.0001   0.001         0.01        0.1   1   10
                                           Strain (%)

                                                                   35              Hashash and Park (2004)
NL Soil Model Parameters-Anchorage
              1.2

               1

              0.8
  G/Gmax




              0.6
                                                                                                   Bootlegger
                        DEEPSOIL                                                                      clay
              0.4
                                                                                                     0.7
                        Bootlegger Clay
              0.2       (Updike et al., 1982)                                           s             0.7

               0                                                                    Reference
              30                                                                      strain         0.05
               0.0001      0.001            0.01           0.1        1   10
                        DEEPSOIL                Strain (%)                            ’ref           N/A
              25
                                                                                       b              0.0
                        Bootlegger Clay
              20
Damping (-)




                        (Updike et al., 1982)

              15
                                                                                        c             1.0
              10                                                                                      0.0
                                                                                       d
                5

                0
               0.0001       0.001           0.01                0.1   1   10
                                                   Strain (%)



                                                                               36               Hashash and Park (2004)
Limitations

    No Pore pressure generation model
      Currently under development

    Implementation of a NN based
     constitutive model




                                37       Hashash and Park (2004)
Questions?




             38   Hashash and Park (2004)
Backup Slides
                        2

                                                              Stiffness proportional
                                                                    damping
 Damping ratio, (%)




                        1

                                    Mass proportional
                                        damping
                                                              Simplified Rayleigh Damping
                                                              Full Rayleigh Damping
                                                              Extended Rayleigh
                        0
                            0   5   10        15         20           25          30           35
                                             Frequency (Hz)

                                                                39               Hashash and Park (2004)
                                  Backup Slides
                                  1000 m Column
                                  Site Period: 5.0 sec
Spectral Acceleration (g)




                            0.1




                     0.01

                                                                                                                100 m Column
                                                                                                                Site Period: 0.9 sec



                                                                             Spectral Acceleration (g)
                              0.01             0.1                  1   10
                                                     Period (sec)
                                                                                                          0.1




                                                                                                                         Input Motion
                                                                                                         0.01
                                                                                                                         (after Deconvolution)
                                                                                                                         Pressure Dependent Model
                                                                                                                         Pressure Independent Model

                                                                                                            0.01             0.1                  1                10
                                                                                                                                   Period (sec)



                                                                                                                            40                        Hashash and Park (2004)

								
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