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UC-1 Series Geotechnical Analysis
UC-1  
Dynamic effective stress analysis for ground(UWLC)
English version Ver.2
Software price US$ 12,600
Rental US$ 3,780-
 
Dynamic effective stress analysis for ground(UWLC)
Japanese version Ver.2
Software price US$ 6,300
Rental US$ 1,890-

Analysis of elementary stress/dynamic analysis of the total stress/
dynamic analysis of effective stress (liquefaction analysis) program
Japanese/English versions

Geotechnical analysis support service

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Introduction
ライン
This program is to analyze dynamic land transformation using finite element method (FEM). Taking into consideration the method of elastic theory based on effective stress, excessive pore water pressure which occurs during earthquakes and the declining of stiffness, it is possible to calculate land transformation by the hour. This program can be applied to investigating the stability of earth structures (banks or raised mounds), the lift of underground structures, and the dynamic interrelation between an earthquake and structures. Another program with function to decide parameters in liquefaction is attached. It allows you to input in a CAD style making easy creation possible. It also accepts reading from SXF files.
The analytic core of this program makes use of the land analysis program by Prof. Ugai and his research laboratory at Gunma University who enjoys advanced analytic theory and brilliant achievements. It is jointly developed by our company which is engaged in the development of the prepost part and the university.


Information

New product
Dynamic effective stress analysis for ground (UWLC) English Ver.2 (Up&Coming '16 Summer Issue)

Technical data
[ Element Test Simulation Tutorial ] (PDF 919KB) ('06.04.04UP)
PZ-Sand & PZ-Clay models

Paper

[ SIMULATION OF SEISMIC BEHAVIOUR OF GRAVITY QUAY WALL USING A GENERALIZED PLASTICITY MODEL ] (PDF,531KB) ('07.08.15UP)
4th International Conference on Earthquake Geotechnical Engineering (June 25-28, 2007, GREECE)
Presentation document (PDF,1,163KB)

The First FORUM8 Design Conference Report on the special lectures

ICCI2004 The First International Conference on Construction IT (15-17 August 2004)
Function and features of the program
ライン
Analytic features
  1. It is possible to set parameters in liquefaction by carrying out simulation for element test.
  2. Identification analysis program by the optimization method is attached so that entered parameter can be set from experiment data.
  3. Parameters of sand structure model (PZ-sand) can be estimated from N value of the standard penetration test
  4. It conducts one-dimensional and two-dimensional analyses.
  5. It is possible to carry out the dynamic analysis of total stress method and of effective analysis (analysis in liquefaction).
  6. 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.
  7. Dynamic analysis of earth and water successively formed on the assumption of water penetration.
  8. Plenty of structure models of land (eight categories) are available and these can be used freely.
  9. It adopts BFGS, which is a line search for calculating convergence.
  10. Stable analysis by making automatic adjustment in time steps of dynamic analysis.

Scope of application
This program is mainly applied to the following investigations.
  1. Investigation of the dynamic interrelation between land and building structures by using the total stress method.
  2. Investigation of stability at an earthquake including earth structures(river banks, for example).
  3. Investigation of the lift of structures in the liquid land.
  4. Investigation of the method against.
  5. Dissipation of Excess Pore Water Pressure Method like Gravel drain method are supported.
  6. Simulation of experiments such as a centrifugal vibration experiment or a large-sized vibration table.
  7. Judgment of minute liquefaction by means of one-dimensional response analysis during earthquakes.

Example of liquefaction countermeasures that can be considered
  1. Method by structures
  2. Consolidation method
  3. Sand compaction pile method
  4. 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
  1. 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.


  2. Beam element
    It is possible to define primary beam element.

  3. Axial spring element
    Definition is given at two contact points. The length of the spring must be 10 - 5 m or longer.

  4. Shearing spring element
    Definition is given at two contact points. The length of the spring must be 10 - 5 m or longer.

  5. Mass element centered on one contact point.
    Definition is given at one contact point.
  6. Damper element
    It indicates declining in the axial and shearing directions.


2.Constituent models
  1. Distortion element model on a plain surface
    • Linear elastic model
    • Laminated elastic model
    • Elastic and complete plastic model
    • Modified Ramberg-Osgood model (RO model)
    • Modified Hardin-Drnevich model (HD model)
    • Ugai-Wakai model (UW-Clay model)
    • Pastor-Zienkiewicz model for sand (PZ-Sand model)
    • Pastor-Zienkiewicz model for clay (PZ-Clay model)
  2. 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.
  3. 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 both-ends node of a spring.

3.Mass matrix and damping matrix
  1. 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 matrix---Concentrated mass matrix or consistent mass matrix
    • Damping matrix---Concentrated damping matrix or consistent damping matrix
    However, you have to use consistent damping matrix if you regard Rayleigh damping as viscous damping.
  2. 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
  1. Degitizing and integral calculus in dynamic equation
    • Explicit method---forward calculus of finite differences.
    • Implicit method---Newmark-βmethod/HHT-α method/WBZ-α method/Generalized-α method.
  2. 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 parameter-determining 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.

Click to enlarge the image.
Identification analysis by the optimization method

■Estimate the sand structure model parameter from N value

As a soil model for liquefaction, elasto-plasticity and PZ-Sand (Pastor-Zienkiewicz) 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 N-value with this function now.

Click to enlarge the image.
PZ-sand 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 cross-section 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 high-standard 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
line
  • 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 elasto-plastic 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 Generalized-α Method, ASME, Journal for Applied Mechanics, 60, 371-375, 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, 283-292, 1977.
  • Hughes, T.J.R., Analysis of Transient Algorithms with Particular Reference to Stability Behavior, Computational Methods for Transient Analysis, North-Holland, 67-155, 1983.
  • Hulbert, G.M. and I. Jang, Automatic Time Step Control Algorithms for Structural Dynamics, Computer Methods in Applied Mechanics and Engineering, 126, 155-178, 1995.
  • Newmark, N. M., A Method of Computation for Structural Dynamics, ASCE, Journal of the Engineering Mechanics Division, 85, EM3, 67-94, 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, 1562-1566, 1981.
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