This movies shows how apply the cross and parallel permeability options for interfaces and where to inspect the relevant results.

The post Using permeability in interfaces appeared first on Plaxis.

This movies explains how to use the multiply command to conveniently change values for a collection of load values, thermal of flow conditions or discharges.

The post Using the multiply command appeared first on Plaxis.

Fixed issues and improvements PLAXIS 3D 2016.02

About fifteen issues have been addressed, including:

• model sometimes temporarily disappearing in Input
• tunnel cross sections would sometimes unnecessarily be closed
  with tiny segments that would lead to problems in intersecting
  and meshing
• Some intersecting and meshing issues
• The "explode" visualization option works again in Input

Fixed issues and improvements PLAXIS 3D 2016.01

About twenty issues have been addressed, including:

•  the setup executed on a system that already has an existing 32-bit PLAXIS 3D will recognize the user information from that version
• fixed several problems with converting PLAXIS 3D Classic projects to PLAXIS 3D 2016
• fixed some rendering issues for wireframes and inactive objects
• fixed a few UDSM-related issues
• improved performance of Output loading particular projects

New and improved features PLAXIS 3D 2016.00

When installing PLAXIS 3D, please make sure any previous installations of beta versions or release candidates have been removed! PLAXIS 3D 2016 ships with and automatically installs an updated version of PLAXIS 3D Classic, which includes a few bugfixes compared to PLAXIS 3D AE.02.

• added polar array creation
• added option to select the number of significant digits used to display numerical values in Input
• new initial phase calculation type (field stress) for direct input of anisotropic and rotated initial stresses
• generation of rock bolts by tunnel designer
• enhanced remote scripting support in Output (e.g. generating plots)
• grout anchor behaviour for embedded beams
• massively improved performance and memory use, particularly when dealing with huge projects
• all applications are 64-bit only for better performance and ability to handle larger projects
• SoilTest supports cyclic DSS soil test
• determination of center lines of volume piles in Output
• tunnel designer supports definition of phasing
• saving of inverse analysis settings in SoilTest
• a Python distribution is included for easier use of the remote scripting facilities
• element quality plot for plate elements
• enhanced geometry import facilities
• A Large number of issues have been fixed

Known issues and compatibility

For the latest information on known issues, and compatibility notes, please visit the Knowledge Base on the Plaxis website: https:/www.plaxis.com/support

CodeMeter firmware and drivers

The minimal required Codemeter firmware and driver version are, respectively, versions 1.18 and 5.20d. The driver version provided with PLAXIS 3D 2016.00 is 5.20d. Plaxis recommends to always use the latest versions.

The post PLAXIS 3D 2016.02 appeared first on Plaxis.

This video explains how to use the PLAXIS Coupling tool to set up coupled soil-structure interaction analysis between PLAXIS 3D 2016.02 and SAP2000 V18

The post Using the PLAXIS Coupling Tool appeared first on Plaxis.

The PLAXIS Viewers are standalone programs and offer you and your clients the ability to view calculated PLAXIS 2D and PLAXIS 3D projects without the need of a licence.

The PLAXIS Viewer is part of your PLAXIS installation starting PLAXIS 2D 2016 and PLAXIS 3D AE.02. You will find the newest version of the PLAXIS Viewer in your installation directory (when you have installed the software). The Viewer works as a standalone application, so it can be copied to other locations or sent to your clients.

The PLAXIS Viewer can also be obtained by selecting the appropriate version and downloading it via these links below:

The post Plaxis Viewer – standalone program to view results appeared first on Plaxis.

In the PLAXIS 2D versions mentioned above in which this spacing value [L_s] is not taken into account to determine the maximum axial skin resistance, you should divide the axial skin resistance by the spacing and use this value as an input value.

We are working on a fix for this.

The post Layer dependent skin resistance of embedded beam row ignores spacing appeared first on Plaxis.

Firewall

Plaxis remote scripting is built using the HTTP protocol. It is in principle possible for any (remote) client to connect to a Plaxis remote scripting server, if this server is activated. In order to prevent third parties interfering with the Plaxis remote scripting server running on your machine (effectively potentially taking over control of your Plaxis application and being able to monitor what kind of actions your remote script is undertaking), it is important to configure your firewall properly (i.e. do not allow incoming requests from the internet or from your local network if you don't need to provide this type of access).

Encryption

Starting with PLAXIS 2D 2017, the remote scripting solution can and does by default use an industry-standard encryption for the communication between server and client(s). We recommend using this encryption, with a strong password. This way an attacker should not be able to send valid requests to your Plaxis installation, even if you do need to open firewall ports for access to Plaxis remote scripting from outside your own computer.

Password renewal

We are aware of another potential attack vector, a replay attack (https://en.wikipedia.org/wiki/Replay_attack). This would involve an attacker monitoring the valid requests you send to the remote scripting server and then sending them again at some later point in time, without knowing their contents. If you are worried about the impact this may have, you can make sure that every time you run the scripting server, you do so with a new strong password. That way previously valid requests logged by an attacker are rendered invalid. The attacker can still perform an immediate replay attack if he replays the requests during the application session in which they were recorded. The only way to prevent this type of attack is to limit access to your remote scripting server using a firewall, as explained above.

The post Encrypted scripting server vulnerable to replay attacks appeared first on Plaxis.

Description

The following article gives information on how to use the Remote scripting feature to create a tunnel using the PLAXIS tunnel designer.

In this example, we will show the Python commands to generate the tunnel cross section of Tutorial Lesson 6 (Excavation of an NATM tunnel)
2D Tutorial 06: Excavation of an NATM tunnel

Geometry of NATM tunnel in tutorial lesson

This Python script was written for PLAXIS 2D 2016.01 in combination with Python 3.4.4.

To better understand the structure of the commands used in the example, some are explained below:

• set command
  • set  is used in PLAXIS Input to set one or more properties of one or more objects. An example is the following:

    set Tunnel_1.CrossSection.Segments[0].ArcProperties.Radius 10.4

    With Python, the set command can be written using the assignment statement set command
    (name = expression):

    g_i.Tunnel_1.CrossSection.Segments[1].ArcProperties.Radius = 10.4

• commands with no parameters
  • In PLAXIS Input some of the commands do not have any parameters defined (as optional). One case is the following command as it is generated in the Input program:
    

    add Tunnel_1.CrossSection
    

    Note that the empty field in the parentheses indicate that there are no parameters defined for this method (command).

Tutorial 6 - Excavation of an NATM tunnel (Python commands)

# first segment defined command by command
tunnel.CrossSection.add()
tunnel.CrossSection.Segments[-1].SegmentType = "Arc"
tunnel.CrossSection.Segments[-1].ArcProperties.Radius = 10.4
tunnel.CrossSection.Segments[-1].ArcProperties.CentralAngle = 22

# function for the rest of segments
def add_arc(tunnel, radius, angle):
    segment = tunnel.CrossSection.add()
    segment.SegmentType = "Arc"
    segment.ArcProperties.Radius = radius
    segment.ArcProperties.CentralAngle = angle

# call the function to create two more segments
add_arc(g_i.Tunnels[-1], 2.4, 47)
add_arc(g_i.Tunnels[-1], 5.8, 50)

# extend to symmetry axis and symmetrically close the shape
tunnel.CrossSection.extendtosymmetryaxis()
tunnel.CrossSection.symmetricclose()


# add subsections
subsection, subsection_segment = tunnel.CrossSection.addsubcurve()
subsection.Offset2 = 3
subsection_segment.SegmentType = "Arc"
subsection_segment.ArcProperties.Radius = 11
subsection_segment.ArcProperties.CentralAngle = 360

# create a list for all segments and subsections that will be intersected
segments_subsections = []
for subsection in tunnel.CrossSection.Subsections[:]:
    segments_subsections.append(subsection)
    for segment in tunnel.CrossSection.Segments[:]:
        segments_subsections.append(segment)

# intersect the created list and delete the odd one
tunnel.CrossSection.intersectsegments(*segments_subsections)
tunnel.CrossSection.delete(tunnel.CrossSection.Subsections[2])

# define plates for slice polycurves, assign material, create negative interface
for tunnel_slice in tunnel.SlicePolycurves[:]:
    g_i.plate(tunnel_slice)
    # next command requires a material to be predefined for the lining
    tunnel_slice.Plate.Material = g_i.Lining
    if tunnel_slice == tunnel.SlicePolycurves[4] or tunnel_slice == tunnel.SlicePolycurves[5]:
        pass
    else:
        g_i.neginterface(tunnel_slice)


# generate the tunnel
g_i.generatetunnel(tunnel)

The post How to create a tunnel using Python appeared first on Plaxis.

A Python script combining forces and displacements for a single wall into a plot and table

Introduction

In order to retrieve and document results for retaining walls (vertical plates) in PLAXIS 2D Output, several plots and tables need to be inspected and copied separately. For instance:

• A plot for the horizontal displacements (u_x)
• A plot for the axial forces (N)
• A plot for the bending moments (M)
• A table for the displacements ( |u|, u_x, u_y)
• A table for the forces (N, Q, and M)

When copying this data for many phases, this can be a lot of work, and is prone to human error, e.g. by taking the wrong phase or by forgetting to press Ctrl+C when inspecting a table.

Python solution

By using the Remote Scripting Server in the Plaxis Output program, we can create a Python script to automatically retrieve the desired displacements and forces for a certain vertical plate. The attached script will ask the user to define the X-coordinate for the vertical plate and to define for which phase the results should be obtained.

The Python script will then:

• Gather the plate results and filter them based on the X-coordinate
• Create a table of these results and copy this table to the Windows clipboard (tab-delimited). This can then easily be pasted into a spreadsheet program.
• Generate a chart, showing the wall with the results for horizontal displacement (u_x), axial force (N) and bending moment (M) in one chart.

Script output - table

The resulting table will be copied to the clipboard to be used in e.g. a spreadsheet program. It will contain a header with info on the phase the results are for and for which X-coordinate the results are taken, followed by the actual data table. The data is stored as tab-separated values.

Based on the final phase of Tutorial Lesson 2, this table will look like this:

PLAXIS 2D Result script: Plate results
For phase: Third excavation stage [Phase_5]
Step number: Step_24
Vertical plate at X = 50.0 m

X    Y      u_x                  u_y                   |u|                 N                      Q                    M                      rotation
[m]  [m]    [m]                  [m]                   [m]                 [kN/m]                 [kN/m]               [kNm/m]                [°]
50   20     0.0224266240723166   -0.00775284541048889  0.0237288870206748  -0.000503572077390047   0.0171521096654468   2.87346535454702e-13  0.480217532450464
50   19.75  0.0245219323623862   -0.00775279974664634  0.0257183022514521  -2.76566870972096      -1.16857362594199    -0.114778674602701     0.480218001424812
50   19.5   0.0266170992800733   -0.00775265919316243  0.0277231617722547  -5.69441776254759      -3.73654034658163    -0.699885794686862     0.480223070463705
50   19.25  0.028712053956832    -0.00775241824433458  0.029740242619305   -8.79201320755032      -7.67343619438683    -2.09749667300932      0.480241927766234
50   19     0.0308067771926515   -0.00775207114821604  0.031767154862919   -12.0637175217222      -12.965949311491     -4.64903832929917      0.480288664180428
[...]

Script output - plot

The Python script will define a matplotlib-chart with one vertical axis for the plate and three horizontal axes: u_x, N and M. This chart is based on the parasites example from Matplotlib.

Based on the final phase of Tutorial Lesson 2, this chart will look like this:

Figure 1. Python generated plot showing combined results for displacements and forces for Tutorial Lesson 2's final phase.

Note: this Python script will directly use the data from the PLAXIS Output program. The only exception is for the horizontal displacement u_x: when the SI unit for length [m] is used, the deformation values for the curve data are converted to [mm] to improve the reading of the generated graph.

Modules used

The Python script requires the following modules:

• The plxscripting module to interact with PLAXIS 2D Output
• The matplotlib module to create a chart
• The pyperclip module to copy the content to the Windows clipboard
• The easygui module to create a nice user interface for the user to set values in order to retrieve results: the X-coordinate of the vertical plate and the phase to retrieve the results for.

All modules are part of the standard PLAXIS 2D 2017 installation that includes a full Python 3.4.x distribution.

Usage instructions for Python script

To use this file:

1. Download the file (use Save As...)
2. Unpack the zip file and copy the *.py file to this folder:
   <PLAXIS 2D installation folder>\pytools\output
   When using the default installation folder for PLAXIS 2D, this would be
   C:\Program Files\Plaxis\Plaxis 2D\pytools\output
3. Restart PLAXIS 2D Output and open a Plaxis file with an activated retaining wall (vertical plate)
4. In the Expert menu, go to Python > Run script > Tools. Here you should see the name of the Python file. When selecting it, it will execute the script to retrieve the results for the plate:
   •  As a table in the Windows clipboard
   •  Followed by generation of the chart

When you do not have access rights to add the script in this folder, alternatively, you can choose to use Expert menu > Python > Run script > Open... to manually open and run the file.

Version

This script has been made for PLAXIS 2D 2017.00 using Python 3.4.x

Disclaimer

This Python script is made available as a service to PLAXIS users and can only be used in combination with a PLAXIS VIP license.
You use this Python script at your own responsibility and you are solely responsible for its results and the use thereof. Plaxis does not accept any responsibility nor liability for the use of this Python script nor do we provide support on its use.

The post Combined plate results in one chart using Python appeared first on Plaxis.

This example involves driving a concrete pile through an 11 m thick clay layer into a sand layer, as can be seen in the figure below. The pile has a diameter of 0.4 m. Pile driving is a dynamic process that causes vibrations in the surrounding soil. Moreover, excess pore pressures are generated due to the quick stress increase around the pile.

In this example focus is placed on the irreversible deformations below the pile. In order to simulate this process most realistically, the behaviour of the sand layer is modelled by means of the HS small model.

In order to inspect the calculation results, please recalculate the Plaxis project: the results are not included to minimize the download size.

This exercise requires the Dynamics module.

The post 2D Tutorial 13: Pile driving appeared first on Plaxis.

Using PLAXIS, it is possible to simulate soil-structure interaction. Here the influence of a vibrating source on its surrounding soil is studied. Due to the three dimensional nature of the problem, an axisymmetric model is used. The physical damping due to the viscous effects is taken into consideration via the Rayleigh damping. Also, due to axisymmetry 'geometric damping' can be significant in attenuating the vibration. The modelling of the boundaries is one of the key points. In order to avoid spurious wave reflections at the model boundaries (which do not exist in reality), special conditions have to be applied in order to absorb waves reaching the boundaries.

In order to inspect the calculation results, please recalculate the Plaxis project: the results are not included to minimize the download size.

This exercise requires the Dynamics module.

The post 2D Tutorial 12: Dynamic analysis of a generator on an elastic foundation appeared first on Plaxis.

This lesson demonstrates the applicability of PLAXIS to agricultural problems. The potato field lesson involves a loam layer on top of a sandy base. Regional conditions prescribe a water level at the position of the material interface. The water level in the ditches remains unchanged. The precipitation and evaporation may vary on a daily basis due to weather conditions. The calculation aims to predict the variation of the water content in the loam layer in time as a result of time-dependent boundary conditions.

In order to inspect the calculation results, please calculate the Plaxis project: the results are not included to minimise the download size.

This exercise requires the PlaxFlow module in order to be able to perform calculations in the Flow mode

The post 2D Tutorial 11: Potato field moisture content appeared first on Plaxis.

In this lesson, the flow around a sheetpile wall will be analysed. The geometry model of Tutorial 3 will be used. The well feature is introduced in this example.

In order to inspect the calculation results, please calculate the Plaxis project: the results are not included to minimise the download size.

This exercise requires the PlaxFlow module in order to be able to perform transient groundwater flow calculations.

The post 2D Tutorial 10: Flow around a sheet pile wall appeared first on Plaxis.

In this chapter the flow through an embankment will be considered in the Flow mode. The crest of the embankment has a width of 2.0 m. Initially the water in river is 1.5 m deep. The difference in water level between the river and the polder is 3.5 m.

In order to inspect the calculation results, please recalculate the Plaxis project: the results are not included to minimize the download size.

This exercise requires the PlaxFlow module in order to be able to perform groundwater flow calculations.

The post 2D Tutorial 09: Flow through an embankment appeared first on Plaxis.

In this tutorial a Ultimate Limit State (ULS) calculation will be defined and performed for the submerged construction of an excavation. The geometry model of Tutorial 03 will be used. The Design approaches feature is introduced in this example. This feature allows for the use of partial factors for loads and model parameters after a serviceability calculation has already been performed.

In order to inspect the calculation results, please recalculate the Plaxis project: the results are not included to minimize the download size.

The post 2D Tutorial 08: Dry excavation using a tie back wall – ULS appeared first on Plaxis.

This example concerns the stability of a reservoir dam under conditions of drawdown. Fast reduction of the reservoir level may lead to instability of the dam due to high pore water pressures that remain inside the dam. To analyse such a situation using the finite element method, a transient groundwater flow calculation is required. Pore pressures resulting from the groundwater flow analysis are transferred to the deformation analysis program and used in a stability analysis. This example demonstrates how deformation analysis, transient groundwater flow and stability analysis can interactively be performed in PLAXIS 2D.

The dam to be considered is 30 m high and the width is 172.5 m at the base and 5 m at
the top. The dam consists of a clay core with a well graded fill at both sides.

In order to inspect the calculation results, please calculate the Plaxis project: the results are not included to minimize the download size.

This exercise requires the PlaxFlow module to be able to perform Fully coupled flow-deformation analyses

The post 2D Tutorial 07: Stability of dam under rapid drawdown appeared first on Plaxis.

This lesson illustrates the use of PLAXIS for the analysis of the construction of a NATM tunnel. The NATM is a technique in which ground exposed by excavation is stabilized with shotcrete to form a temporary lining. Rapid and consistent support of freshly excavated ground, easier construction of complex intersections and lower capital cost of major equipment are some of the advantages of NATM. Some of the limitations of this method are that it is slow compared to shield tunnelling in uniform soils, dealing with water ingress can be difficult, and it demands skilled man power.

In order to inspect the calculation results, please calculate the Plaxis project: the results are not included to minimise the download size.

This exercise requires the VIP module in order to be able to use the Hoek-Brown material model.

The post 2D Tutorial 06: Excavation of an NATM tunnel appeared first on Plaxis.

PLAXIS 2D has special facilities for the generation of circular and non-circular tunnels and the simulation of a tunnel construction process. In this lesson, the construction of a shield tunnel in medium soft soil and the influence on a pile foundation is considered. A shield tunnel is constructed by excavating soil at the front of a tunnel boring machine (TBM) and installing a tunnel lining behind it. In this procedure, the soil is generally over-excavated, which means that the cross-sectional area occupied by the final tunnel lining is always less than the excavated soil area. Although measures are taken to fill up this gap, one cannot avoid stress re-distributions and deformations in the soil as a result of the tunnel construction process. To avoid damage to existing buildings or foundations on the soil above, it is necessary to predict these effects and to take proper measures. Such an analysis can be performed by means of the finite element method. This lesson shows an example of such an analysis.

In order to inspect the calculation results, please calculate the Plaxis project: the results are not included to minimise the download size.

The post 2D Tutorial 05: Settlements due to tunnel construction appeared first on Plaxis.

The construction of an embankment on soft soil with a high groundwater level leads to an increase in pore pressure. As a result of this undrained behaviour, the effective stress remains low and intermediate consolidation periods have to be adopted in order to construct the embankment safely. During consolidation the excess pore pressures dissipate so that the soil can obtain the necessary shear strength to continue the construction process.

This lesson concerns the construction of a road embankment in which the mechanism described above is analysed in detail. In the analysis three new calculation options are introduced, namely a consolidation analysis, an updated mesh analysis and the calculation of a safety factor by means of a safety analysis (phi/c-reduction).

In order to inspect the calculation results, please calculate the Plaxis project: the results are not included to minimise the download size.

The post 2D Tutorial 04: Construction of a road embankment appeared first on Plaxis.

This example involves the dry construction of an excavation. The excavation is supported by concrete diaphragm walls. The walls are tied back by prestressed ground anchors.
PLAXIS allows for a detailed modelling of this type of problem. It is demonstrated in this example how ground anchors are modelled and how prestressing is applied to the anchors. Moreover, the dry excavation involves a groundwater flow calculation to generate the new water pressure distribution. This aspect of the analysis is explained in detail.

Note: with PLAXIS 2D 2012, Plaxis introduced the embedded pile row feature. With this new feature, ground anchors can be modelled more realistically compared to the older method of using a geogrid to model the grout body (bonded length).

The post 2D Tutorial 03: Dry excavation using a tie back wall appeared first on Plaxis.