
Analysis method
Analysis category
# Static totalstress analysis
Analysis models
# Plane strain analysis
# Axisymmetric analysis
Earthquake resistant river structure standard
Main features

# Stage analysis 


The stage analysis, or the phased construction analysis can be performed.
It is possible to change material parameters, boundary conditions, and
stress release factors at each stage. 

# Shear strength reduction (SSR) analysis 


The shear strength reduction (SSR) analysis can be performed using three
kinds of elasticperfectly plastic constitutive laws. It is possible to
evaluate global safety factor and slip surface by SSR analysis at each
stage. 

# Local factor of safety 


It is possible to calculate the local safety factors at each Gaussian point. 

# Coordination with seepage analysis 


It is possible to use nodal water pressure loads from seepage analysis
(Note: This is for the analysis using load module). 

# Combination of stage and SSR analyses 


It is possible to perform both deformation and stability analyses at the
same time by combining stage and SSR analyses, and to deal with a wide
range of soil related problems such as filled/excavated area, slope stability,
bearing capacity, etc. 

# Mixed assignment of constitutive laws 


It is possible to assign different constitutive laws for each material. 

2007 Guidelines for QuakeResistance Testing of River Structures 


Deformation analysis: Before liquefaction, Under liquefaction, Volume
compression after liquefaction 

2016 Guidelines for QuakeResistance Testing of River Structures 


Soil liquefaction analysis based on the March 2016 Edition of " Guidelines
for QuakeResistance Testing of River" established by River Improvement
and Management Division, Water and Disaster Management Bureau, Japan Ministry
of Land, Infrastructure, Transport and Tourism is feasible. "Deformation
analysis prior to an earthquake (before liquefaction)", "Deformation
analysis after an earthquake (after liquefaction)", and "Amount
of land subsidence (deformation analysis) caused by bulk compression of
liquefaction layer" can all be assigned to each stage of the analysis
for a very thorough analysis.
Selfweight induced deformation analysis involves deformation analysis
before an earthquake (before liquefaction)" and deformation analysis
after an earthquake (after liquefaction), and then taking the difference
of the results from each analysis to compute the amount of land subsidence
caused by liquefaction. The amount of land subsidence (deformation analysis)
caused by the bulk compression of the liquefaction layer is calculated
separately to the deforamtion analysis before and after an earthquake.
By adding the value for the amount of land subsidence caused by the bulk
compression of the liquefaction layer to the value for the amount of land
subsidence caused by liquefaction, the overall displacement of the model
of interest can be determined. 

Work flow of deformation analysis 

Boundary conditions
It is possible to define the following four boundary conditions.
# Supporting point (horizontal and vertical rollers, fixed, pin,
enforced displacement)
# Multi point constraint (MPC)
# Spring supporting point
# Pin connection
Element libraries
It is possible to define the following finite elements.
Category 
Element 
2D 
Axisymmetric 
Note 
Line 
Beam 
o 
 
First order element 
Bar 
o 
 
First order element 
Axial spring 
o 
 
Including spring supporting point 
Shear spring 
o 
 
Including spring supporting point 
Torsion spring 
x 
 

Distributed axial spring 
x 
 

Distributed shear spring 
x 
 

Surface 
Threenode triangle 
o 
o 
First order element for 2D & axisymmetric analyses 
Fournode quadrilateral 
o 
o 
First order element for 2D & axisymmetric analyses 
Sixnode triangle 
o 
o 
Second order element for 2D & axisymmetric analyses 
Eightnode quadrilateral 
o 
o 
Second order element for 2D & axisymmetric analyses 
Joint 
Fournode line joint 
o 
o 
Apply between 2D first order elements 
Sixnode line joint 
o 
o 
Apply between 2D second order elements 
o: supported, x: unsupported.
Constitutive law models
# Constitutive law models for elements in plane strain and axisymmetric
analyses
It is possible to use the following constitutive law models for elements
in plane strain and axisymmetric analyses. Linear and laminated elasticity
models can be used as notension materials.
Category 
Constitutive law 
Note 
Elastic 
Linear elasticity 
Isotropic 
Laminated elasticity 
Anisotropic 
Shear stiffness reduction material 1 
2007 Guidelines for QuakeResistance
Testing of River Structures / 2016 Guidelines for QuakeResistance
Testing of River Structures 
Shear stiffness reduction material 2 
2007 Guidelines for QuakeResistance
Testing of River Structures 2016 Guidelines for QuakeResistance
Testing of River Structures 
nonlinear elastic 
Dmin 
Technique by CRIEPI 
Nonlinear 
HD (HardinDrnevich) 

RO (RambergOsgood) 

UWClay (UgaiWakai) 

Elasticperfectly plastic 
MC (MohrCoulomb) 
Associative/nonassociative flow rule 
DP (DruckerPrager) 
Associative/nonassociative flow rule 
MCDP (MohrCoulomb / DruckerPrager) 
Nonassociative flow rule 
Elastoplastic 
PZSand (PastorZienkiewicz) 

PZClay (PastorZienkiewicz) 

Notension 
Linear elasticity 

Laminated elasticity 

Bi linear 
Liquefied material 1 
2007 Guidelines for QuakeResistance
Testing of River Structures 
Liquefied material 2 
2016 Guidelines for QuakeResistance
Testing of River Structures 
# Constitutive law models for beam, bar, spring, and joint elements
It is possible to use the following constitutive law models for beam, bar,
spring, and joint elements.
Element 
Constitutive law 
Support 
Note 
Beam(Mφ) 
(1) Linear elasticity 
o 

(2) Bilinear x 
x 

(3) Trilinear x 
x 

Bar 
(1) Linear elasticity 
o 

(2) Bilinear 
o 

(3) Trilinear 
x 

Spring 
(1) Linear elasticity 
o 
Including spring supporting point 
(2) Bilinear 
o 
Including spring supporting point 
(3) Trilinear 
x 

Joint 
(1) Linear elasticity 
o 

(2) MC (MohrCoulomb elasticperfectly plasticity) 
o 

o: supported, x: unsupported.
Loads
It is possible to use the following loads.
# Nodal force load (2D, axisymmetric)
# Uniform pressure load (2D, axisymmetric)
# Self weight load (2D, axisymmetric)
# Seismic inertia load (2D)
# Nodal water pressure load (2D, axisymmetric)
Note GeoFEAS2D can consider effects of water pressure change on soil by taking into account water pressure as nodal load.
Postprocessor (Aftertreatment)
Output analysis of processor (Analysis section) is processed.Output / confirmation
of result figures and numerical values are carried out.
In this program, the following can be output mainly.
# Model figure
# Deformation figure
# Vector diagram
# Contour figure
# Distribution map
# Numeric output
Combination with the UC1 Earth retaining work design (Option)
In Temporary sheathing work design, it allows examining the effect to surrounding ground by "enforcement
displacement method" which works vertical overburden pressure on the
bottom of excavation if needed, giving the FEM analysis model that modeled
only ground to the displacement of earth retaining wall from elastoplastic
analysis as enforced displacement.



Elastoplastic result of
Temporary sheathing work 
Earth retaining work FEM
(Input screen of the forced displacement method) 
Earth retaining work FEM
(Contour figure of the forced displacement method) 
Cooperation with UC1 Consolidation settlement calculation
The new and improved version of GeoFEAS2D can be linked with "Consolidation Settlement Calculation", another popular UC1 Series product, to take into account consolidation due to compression (consolidation settlement and immediate settlement) when performing liquefaction analysis. Consolidation Settlement Calculation program allows users to set up a complete scenario of consolidation settlement from the creation of soil geometry and assignment of soil layers and vertical load to the calculation of the settlment due to consolidation. The soil model created with its soil geometry and soil layers defined, and subjected to vertial load for consolidation settlement calculation using Consolidation Settlement Calculation program can be imported to GeoFEAS2D for a seamless soil liquefaction analysis.

Assessment on the influenece of sunshine
obstruction on site soils 
Auto mesh function
In case of model creation of like tunnel, mesh division by defining minimum
required lines such as stratum boundary reduces the time of model creation.
Applicable scope
This product is mainly applicable to the following problems.
# Stressdeformation analysis of soil
# Slope stability analysis
# Earth retaining works excavation analysis
# Analysis of surrounding soil effect by shield tunnel construction
# NATM tunnel construction analysis
# Study of water pressure variation effect on soil
# Study of soilstructure interaction
# Ground response acceleration method
■Enhancement of CIM function on the
geotechnical analysis series products
We enhanced the CIM (Construction Information Modeling)
function of various products in the geotechnical analysis
series. The programs can cooperate terrain data or data
created with each geotechnical analysis programs smoothly. 

Data linkage using terrain data file (*.GF1) 
Geotechnical Finite element Elastoplastic Analysis Software
(GeoFEAS)2D Ver.3
The amount of displacement imported to Flexible structure sluiceway design for further analysis
By importing results of ground deformation analysis
(settlement / horizontal displacement distribution) to the
"Flexible structure sluiceway design", the level2 seismic test
for the longitudinal direction can be performed.



GeoFEAS2D 

Flexible structure sluiceway design 
It can modelize only ground
that a surrounding ground
effect analysis is conducted in the Temporary sheathing work design.
The ground deformation can be calculated by giving the wall
displacement as the forced displacement. 
Dynamic effective stress analysis for ground (UWLC)
Acceleration rate imported to Slope stability analysis
for further analysis
When applying the Newmark method to high embankments with a height of about 30 m or more, it is necessary to input the response acceleration waveform of the slip
soil mass as the ground motion.
Data linkage between
"Dynamic effective stress analysis for ground (UWLC)" and "Slope stability analysis"
corresponds to the Newmark method analysis calculated by using
the response acceleration waveform. The level2 seismic
stability calculation for high embankment and large embankment.



UWLC 

Slope stability analysis 

2D seepage analysis(VGFlow2D)
Water line data imported to GeoFEAS2D
Water level data imported to UWLC
Water line and potential line imported to Slope stability analysis
Saturated / unsaturated seepage FEM analysis results can be
reflected by file linkage (*.PRS [water line], *.PTN [isopotential line]). 
GeoFEAS Flow3D (limited to the seepage analysis)
Water level data imported to LEM3D
Analysis results computed with
GeoFEAS Flow3D (limited to the seepage analysis) or third party's product
can be imported to 3D slope stability analysis(LEM). It
creates underground water level required for landslide
analysis and enables the 3D slope stability analysis.

