Function and features of the program


Analytic features
 It is possible to set parameters in liquefaction by carrying out simulation
for element test.
 Identification analysis program by the optimization method is attached
so that entered parameter can be set from experiment data.
 Parameters of sand structure model (PZsand) can be estimated from N value
of the standard penetration test
 It conducts onedimensional and twodimensional analyses.
 It is possible to carry out the dynamic analysis of total stress method
and of effective analysis (analysis in liquefaction).
 Applied elements for total stress method (ignoring water pressure) and
applied elements for effective stress method (considering water pressure)
can be used in mixed situations.
 Dynamic analysis of earth and water successively formed on the assumption
of water penetration.
 Plenty of structure models of land (eight categories) are available and
these can be used freely.
 It adopts BFGS, which is a line search for calculating convergence.
 Stable analysis by making automatic adjustment in time steps of dynamic
analysis.
Scope of application
This program is mainly applied to the following investigations.
 Investigation of the dynamic interrelation between land and building structures
by using the total stress method.
 Investigation of stability at an earthquake including earth structures(river
banks, for example).
 Investigation of the lift of structures in the liquid land.
 Investigation of the method against.
 Dissipation of Excess Pore Water Pressure Method like Gravel drain method
are supported.
 Simulation of experiments such as a centrifugal vibration experiment or
a largesized vibration table.
 Judgment of minute liquefaction by means of onedimensional response analysis
during earthquakes.
Example of liquefaction countermeasures that can be considered
 Method by structures
 Consolidation method
 Sand compaction pile method
 Gravel drain method
Analysis functions 
Initial stress analysis 

All stress analysis 



Dynamic analysis 

All stress analysis 


Valid stress analysis (liquefaction analysis) 

Flow of analysis model creation 
 2D FEM model can be created by simple CAD like operations.
 CAD data (SXF) importing ts supported.
 Mesh division (block division method)
 Simple creation of 1 dimension analysis model
 Mesh data export
 Table of material parameter



■Theory of analysis
As available methods against liquefaction are to be investigated, there
are various possible methods: by means of structures, solidarity, sand
compaction, pile and excessive pore water pressure.
1.Factor library
 Distortion element on a plain surface
It is possible to define four elements:triangular element at three contact
points,triangular element at six contact points,quadrangular element at
four contact points and quadrangular element at eight contact points.
 Beam element
It is possible to define primary beam element.
 Axial spring element
Definition is given at two contact points. The length of the spring must
be 10  5 m or longer.
 Shearing spring element
Definition is given at two contact points. The length of the spring must
be 10  5 m or longer.
 Mass element centered on one contact point.
Definition is given at one contact point.
 Damper element
It indicates declining in the axial and shearing directions.
2.Constituent models
 Distortion element model on a plain surface
 Linear elastic model
 Laminated elastic model
 Elastic and complete plastic model
 Modified RambergOsgood model (RO model)
 Modified HardinDrnevich model (HD model)
 UgaiWakai model (UWClay model)
 PastorZienkiewicz model for sand (PZSand model)
 PastorZienkiewicz model for clay (PZClay model)
 Beam element model
Linear elastic model or bilinear model can be used as stability feature
in the axial direction and shearing spring element. It is also possible
to define the concentrated mass at contact points at both the ends of spring.
 Spring element model
As the stability characteristic of the direction of an axis, and the shear
spring element which is not carried out, an alignment elastic model or
a bilinear model is applicable.
Moreover, node concentration mass can be defined with the direction of
an axis and the shear spring element which is not carried out of this product
as the bothends node of a spring.
3.Mass matrix and damping matrix
 Concentrated matrix and consistent matrix
In this program it is possible to choose either concentrated matrix or
consistent matrix to be applied to mass matrix and damping matrix.
 Mass matrixConcentrated mass matrix or consistent mass matrix
 Damping matrixConcentrated damping matrix or consistent damping matrix
However, you have to use consistent damping matrix if you regard Rayleigh
damping as viscous damping.
 Rayleigh damping
Energy damping covers viscous and fugitive dampings as well as aftereffect
damping.In this program Rayleigh damping can be considered to be viscous
damping.
4.Dynamic equation and simultaneous equation
 Degitizing and integral calculus in dynamic equation
 Explicit methodforward calculus of finite differences.
 Implicit methodNewmarkβmethod/HHTα method/WBZα method/Generalizedα
method.
 Solution of simultaneous equation
This program stores into memory total rigid matrix by means of skyline
method.
As solution of simultaneous equation it adopts LDLT resolving method which
is changed from Gaussian elimination.
■Identification analysis of the material parameter In this version, the parameterdetermining function has been improved. In addition to the originally attached elemental test simulation with the function to decide liquefaction parameters, an identification analysis by optimization method has been added as the attached program. A function to estimate sand parameters from standard penetration test value also has been added to the material parameter setting of main program.
Identification analysis by the optimization method
■Estimate the sand structure model parameter from N value
As a soil model for liquefaction, elastoplasticity and PZSand (PastorZienkiewicz) are available in UWLC. Until now, it was necessary to obtain the angle of the internal friction and the deformation coefficient and to calculate the parameter to define the alternation line in advance in order to determine the parameter. Alteration line defines shift in constriction and swelling of sand dilatancy in the stress space. Sand constricts if Mohr's stress circle is within the alteration line, and if not, it swells. Parameters can be estimated from Nvalue with this function now.
PZsand parameter estimation
■Representational function of the analyzed results
It supports displaying model diagram, distortion diagram, time history diagram, drawing of characteristic force of restitution, responsive spectrum diagram, Fourier spectrum diagram, contour diagram, diagram of crosssection force, main stress/main distortion. It also supports representation in animation.
■Literature introducing UWLC
UWLC is introduced as an example and overview of dynamic deformation analysis
method.
"Design and construction manual about highstandard embankment"
(published in March 2000 by the Foundation for Riverfront Improvement and
Restoration)
■Enhancing CIM features of Geo technical Analysis series
CIM (Construction Information Modeling) features of Geo technical Analysis
series are more enhanced, and data can be cooperated smoothly with terrain
data and geo technical software series. 

Application criteria and References


 Matrix and finite element method [revised version] (O.C. Zienkiewicz, R.L.Taylor,
Kagaku Gijutsu Shuppan, Inc.) (in Japanese)
 FEM series for geotechnical engineers 1 First learning of FEM (The Japanese
Geotechnical Society) (in Japanese)
 FEM series for geotechnical engineers 2 Understanding FEM (The Japanese
Geotechnical Society) (in Japanese)
 FEM series for geotechnical engineers 3 Using elastoplastic FEM (The Japanese
Geotechnical Society) (in Japanese)
 Science on liquefaction (Fusao Oka, Kinmiraisha Company) (in Japanese)
 Dynamic analysis and seismic design Vol.2 Method of dynamic analysis (The
Japanese Geotechnical Society) (in Japanese)
 Chung, J. and G.M. Hulbert, A Time Integration Algorithm for Structural Dynamics with Improved Numerical Dissipation: The Generalizedα Method, ASME, Journal for Applied Mechanics, 60, 371375, 1993.
 Hilber, H.M., T.J.R. Hughes and R.L. Taylor, Improved Numerical Dissipation for Time Integration Algorithms in Structural Dynamics, Earthquake Engineering and Structural Dynamics, 5, 283292, 1977.
 Hughes, T.J.R., Analysis of Transient Algorithms with Particular Reference to Stability Behavior, Computational Methods for Transient Analysis, NorthHolland, 67155, 1983.
 Hulbert, G.M. and I. Jang, Automatic Time Step Control Algorithms for Structural Dynamics, Computer Methods in Applied Mechanics and Engineering, 126, 155178, 1995.
 Newmark, N. M., A Method of Computation for Structural Dynamics, ASCE, Journal of the Engineering Mechanics Division, 85, EM3, 6794, 1959.
 Wood, W.L., M. Bossak and O.C. Zienkiewicz, An Alpha Modification of Newmark's
Method, International Journal for Numerical Methods in Engineering, 15,
15621566, 1981.

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