 Q&A
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1. Function / Overview |
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| Q1-1. |
Can we analyze with the seismic wave of hachinohe wave? |
| A1-1. |
For the horizontal acceleration data, the arbitrary seismic wave including
hachinohe wave can be used.
If you want to adjust the maximum value of the acceleration, you can use
the menu to adjust the input waveform in the window for loading the seismic
wave file in the setting of loading stage.
In general, the method that K-NET developed in NIET(National Research Institute
for Earth Science and Disaster Prevention) is used to obtain the seismic
wave. |
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| Q1-2. |
Can we perform comparative analysis for the basic input waveform and the
ground surface output waveform? |
| A1-2. |
Yes, it is possible. You can output the data into excel file format for
comparisons. |
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| Q1-3. |
Can we extract the maximum value of horizontal force, foundation pile stress,
and ground surface of acceleration based on the whip swing phenomenon of
the tower. |
| A1-3. |
To extract the maximum value of the horizontal force in the tower, please
model the tower with the beam member and check the input in the time-history
to detect the maximum value.
The foundation pile is processed similarly.
Please display the time-history diagram, and right mouse click placing
the cursor over the screen.
The menu which has the graph edit function is displayed, and the data is
exported in excel format.
It is suggested that you should detect the maximum value from the data
and verify it in the section force diagram of that time.
It is better to draw the time-history diagram separately as the maximum
value of NMQ (shear force) does not necessarily occur at the same time.
The acceleration of the ground surface is processed in the same way as
the above mentioned section force.
Please focus on the arbitrary node point and export the data after drawing
the time-history diagram to detect the maximum value (absolute value). |
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| Q1-4. |
Can we export the acceleration waveform as the text file? |
| A1-4. |
Yes, perform a right mouse click on the graph after displaying the time-history
waveform to show Edit menu then select Download, and the text file. |
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| Q1-5. |
Can we perform self-weight analysis? |
| A1-5. |
Yes, UWLC has the function of self-weight analysis. It allows a two step
process - initial stress analysis(=self-weight analysis) and dynamic analysis
separately or concurrently. |
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| Q1-6. |
In the event that liquefaction occurs, can we depict the behavior (including
dynamic behavior and residual deformation) after completing the liquefaction? |
| A1-6. |
Yes, it is possible. UWLC allows the consideration of excess pore pressure
dissipation (consolidation phenomenon) after earthquake as this program
takes into account of the ground water percolation phenomenon. |
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| Q1-7. |
I want to give the inertial force, can we perform in the load method like
push over analysis(obligate horizontal force)? |
| A1-7. |
Please see the following:
- The push over analysis is the analysis method for obtaining the relation
between the load and the displacement by loading the seismic static load
incrementally to the analysis model which takes into account the nonlinearity
of the ground and structures.
- The load that gradually increases that cannot be expressed though the horizontal
force can be given to the fulcrum (node) statically in the initial stress
analysis (static analysis).
- In a dynamic analysis, if the node concentration mass element is defined,
and the acceleration that increases gradually as a dynamic load is entered,
the inertia force of the structures can be considered.
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| Q1-8. |
Can we assess the residual displacement with consideration of liquefaction
occurrence? |
| A1-8. |
Yes, it is possible. |
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| Q1-9. |
Can we generate regular mesh in mesh dividing function(not mesh auto dividing)?
For the part where the division number is different, can we automatically
adopt and adjust the triangle element? |
| A1-9. |
Yes, this is available. |
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| Q1-10. |
Can we use UWLC to check the ground sinking caused by setting of tunnel,
sluice, and sluice pipe? |
| A1-10. |
Yes, please use the initial stress analysis function of UWLC to check the
ground sinking. The elastic model and the elastic completed plastic model(Mohr-Coulomb/Drucker-Prager)
can be applied as the ground structure model. However, if you perform the
gap construction step analysis, the analysis part of this program works
normally, but some functions of pre-post part cannot be supported. Therefore
please note that if you conduct the construction step analysis, you cannot
perform all the data creation and result adjustment automatically. |
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2.Limitation |
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| Q2-1. |
Is there the limitation for element number and node number? |
| A2-1. |
No, there is no limitation for them. |
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3.Analysis theory |
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| Q3-1. |
In 2D analysis, what do you think of the depth length of A(section area
of soil column) in calculating formula of viscous boundary. |
| A3-1. |
UWLC is the software for 2D analysis, the focus is on plane strain problem.
The plane strain problem was meant to process as 2D with the assumption
of the condition that there is no deformation in depth direction of 3D
model and the depth length is the unit length.
This SI unit becomes 1m.
Therefore, the viscous boundary of the soil column has 1m in depth, and
its width is the length of added the two halves between case points. |
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| Q3-2. |
Could you indicate the difference in water line input and geological layer
line input? |
| A3-2. |
The water line is treated in the same manner as the geological layer line,
therefore the terrain data has to be defined by separating the different
geological layer at the top and bottom.
The water line which is regarded as the free water surface in dynamic analysis
serves as the boundary surface where the excess gap water pressure is dissipated. |
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| Q3-3. |
Are the section force and the displacement of structure calculated by the
stress displacement method? |
| A3-3. |
No, they are not calculated by the stress displacement method.
The structures(wall, pile, anchor member, and box) which are modeled in
FEM as the beam element are analyzed in FEM(static analysis, dynamic analysis)
with the entire ground. They are the section force and the displacement
of the resulted beam element. |
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4.Input |
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| Q4-1. |
I want to perform the integration with the subdivided one-tenth of the
input waveform interval Δt, and export the results.
Can I arbitrarily set up the time interval of the integration? |
| A4-1. |
Please input one-tenth of the time interval for input waveform data in
[Initial value of time interval], and input the value in [time interval
of time-history] in [Analyze]-[Output]tab.
Each input value can be arbitrarily set within the specified range. |
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5.Modeling |
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| Q5-1. |
Please tell me the modeling method for geotextile. |
| A5-1. |
It is assumed to be modeled with the initial stress analysis of UWLC and
the stage analysis is required.
In the event of combining the ground and geotextile, please set the ground
as solid element, the geotextile as beam or bar element, and then connect
the node-to-node of predefined ground so that the rigidity of the geotextile
is added, and the water moves between the ground elements.
When the initial stress analysis doesn't converge, you can calculate the
initial stress by stage analysis with another static finite element analysis
program.
Stage 1: Smooth ground
Stage 2: Installation of geotextile
Stage 3: Banking construction
After calculating the initial stress, please move to the dynamic analysis
by switching the file.
Other static stress analysis program is required for stage analysis. GeoFEAS2D
can be used for it. |
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| Q5-2. |
How much range should be considered when dynamic analysis is performed
and the amount of transformation of the soil when time-history is examined?
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| A5-2. |
In general, it should be around three to five times of the ground height.
Ideally, it is thought OK if the steadiness can be seen in the model of
the analysis result after trying out the number of patterns. |
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| Q5-3. |
Is it possible to analyze the structure (retaining wall etc.) on the liquefaction
ground together? |
| A5-3. |
Yes, it is possible.
For instance, the structure and the ground can be analyzed together by
modeling and entering the pile foundation in the ground as the beam element,
or modeling and entering the caisson quay as a solid element. |
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| Q5-4. |
What is the length of the model required from the examination object range
to the lateral boundary? Please tell me the standard value. |
| A5-4. |
It is preferable that the longer model is unaffected from the lateral boundary
condition.
However, we need to consider the model size and calculation time.
It is suggested that the horizontal banking width level is lowest.
Please analyze the model with 50m each on both sides for the banking width(toe
slope width) 50m, a total of 150m in the horizontal direction, 83m to the
base surface in the vertical direction in the sample data.
In the analysis example, some models are 100m or 200m long.
It would be better if there are clear standards which indicate the multiple
factor for horizontal/vertical direction based on the dam body size (or
excavation range) to decide the model range, but it is actually decided
by designer in many cases. |
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| Q5-5. |
Can we model with the polygonal foundation(pile foundation arrangement
in the circle)? |
| A5-5. |
This product is supposed to perform the analysis of the model with 1m of
depth for the ground part. It is necessary to consider modeling the structures
with 1m of depth for under the ground part.
The following method will be appropriate for this case.;It is assumed that
the footing foundation has a depth of 18m for modeling, and the rigidity
of the number of piles for the overlapped piles is divided with the depth
of 18m. Consider the pile stiffness which resulted from the above value
converted per 1m.
Please decide on the availability based on your own discretion. |
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| Q5-6. |
Can we perform the modeling by setting the accumulator(cylinder that the
space was secured between the structure frame) around the bridge pier pillar
section to prevent the shaking of bridge pier pillar from spreading to
the levee banking directly? |
| A5-6. |
When the ground model with the hole of water well is shaped in the bank,
and can be substituted with the model with the beam penetrating into the
bottom of the water well, it is possible.
Please combine the right and left ground of the water well in MPC to move
similarly.
You can enter the arbitrary frame in the beam element part that projects
from the ground level.
If you consider a width of several meters for the bridge pier pillar (if
you think it is not as thin as a cast-in-place pile), please consider the
possibility of holes present in the bank. |
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| Q5-7. |
Can we represent the adhesion cutting of the caisson and the ground?
(For example, putting the shear spring of bilinear between the structure
and the ground. ) |
| A5-7. |
Yes, it is possible.
In addition, it is also possible to express by setting up a thin weak layer.
In general, it is thought that the joint element should be defined, but
in fact the joint element cannot be defined with current UWLC. |
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| Q5-8. |
Please tell me the method for expressing the ground which continues in
semi-infinity on the boundary surface if there are any available. |
| A5-8. |
The viscous boundary is generally set to the bottom boundary.
In UWLC, the viscous boundary is set by using the damper element.
For the lateral boundary, the equal displacement boundary which uses the
MPC boundary condition is set in case of the stratification ground and
the viscous boundary is set in case of the irregular ground. |
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6.Synchronization |
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| Q6-1. |
Can we use the analytical result of GEOFEAS2D which considers construction
step as the initial stress force of UWLC? |
| A6-1. |
The warp and the stress are written in the output file of GeoFEAS2D (with
extension ott).
Please copy from the file to the file (with extension str) where the initial
stress of UWLC is saved so that the initial stress can be set based on
the stress which performed the stage analysis
The file name should be similar. |
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