This document validates the Soft Soil Creep model in PLAXIS. The undrained triaxial creep behaviour of Haney clay is simulated, using the material parameters reported by Matsui & Abe (1988). The results are compared with test data provided by Vaid & Campanella (1977), including constant strain rate shear tests and undrained triaxial creep tests. An extensive validation of the Soft Soil Creep model is presented by Stolle, Bonnier & Vermeer (1997).

The post Soft Soil Creep model – undrained triaxial creep behaviour of Haney clay appeared first on Plaxis.

This document verifies that the Hoek-Brown model is correctly implemented in PLAXIS. For that purpose, the elasto-plastic behaviour of a rock mass is studied via a circular opening subjected to in situ stress in generalized Hoek-Brown material ( α ≥ 0.5 ). PLAXIS results are verified against the closed form solution presented by Carranza-Torres (2004).

It is concluded that the results are in good agreement and the Hoek-Brown model is correctly implemented in PLAXIS.

The post Hoek-Brown material model appeared first on Plaxis.

Fixed issues in PLAXIS 2D 2016.01

A large number of issues have been addressed, including:

• some issues in the automatic centerline calculation
• a bug in the snaplinear command for particular geometric configurations
• accidental resetting of a property value to 0 in the case of "Various" multiselection
• a number of issues with scripting in Output

New and improved features PLAXIS 2D 2016

When installing PLAXIS 2D, please make sure any previous installations of beta versions or release candidates have been removed!

• 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
• added the possibility to limit the number of calculation steps stored during some calculations
• added a semi-automatic option for the substep determination
• added several pre-calculation warnings for dynamics calculations
• added possibility to define rock bolts in tunnels
• added possibility to use commands to create and export plots in Output
• added possibility to fix all nodes in the model horizontally or vertically during a dynamic calculation
• enhanced the geometry cleaning/snapping capabilities: it is now possible for polygons to be modified too in order to fix geometric inaccuracies
• the THM module supports temperature-dependent water properties
• ice saturation can be displayed in Output
• added possibility to automatically determine the centerline of any cluster in Output, for calculating structural forces in volumes
• added cyclic DSS test in SoilTest

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 5.22a. The driver version provided with PLAXIS 2D 2016 is 5.22a. Plaxis recommends to always use the latest versions.

The post PLAXIS 2D 2016.01 appeared first on Plaxis.

Unfortunately, there is no workaround for the issue with a manual Axis function for line elements in PLAXIS 3D 2016.00. Users are advised not to use a manually defined local axis function for line elements (e.g. beams, embedded beams) in this version.

We will solve this in an upcoming update pack.

The post Manual Axis function for lines leads to crash while loading the model in PLAXIS 3D 2016.00 appeared first on Plaxis.

The Frozen and Unfrozen Soil model constitutes a soil model implemented in PLAXIS, capable of describing the mechanical behaviour of frozen soils as a function of temperature, up to the unfrozen state and vice versa. The present constitutive model is the result of a collaboration between the Norwegian University of Science and Technology (NTNU) and Plaxis bv. The aim of this model is to provide a reliable design tool to evaluate the influence of climate/temperature changes in a variety of engineering problems. The increase of engineering activities in cold regions, projects involving artificial ground freezing and consequences of global warming lead to geotechnical applications which deal with frozen/unfrozen ground.

Frost heave as a result of a long-term drop in air temperature

The constitutive model developed by Amiri, Grimstad, Kadivar & Nordal (2016) characterises the mechanical behaviour of frozen soils as a function of temperature, up to the unfrozen state and vice versa. The Frozen and Unfrozen Soil Model is implemented as a user-defined soil model (UDSM) in PLAXIS, using the fully coupled THM calculation options.

In order to obtain the model, send your request for the Frozen and Unfrozen Soil model using this contact form. Support on the use of the Frozen and Unfrozen Soil Model is only provided for this DLL under the conditions of the PLAXIS VIP support service and Article 10 of the End-User Licence Agreement.

The post The Frozen and Unfrozen Soil Model appeared first on Plaxis.

With the polar array tool, you can effortlessly copy objects in circular patterns. Useful to create circular shafts, and forepoling.

The post New in PLAXIS 3D 2016: Polar array tool appeared first on Plaxis.

In PLAXIS 3D 2016 the CAD import functionality has been improved, supporting *.DXF, *.STEP and *.brep formats. NURBS surfaces, solids, splines can now be imported easily. Native Autocad solids can be imported without the need of discretizing them into triangulated objects first. This does not only save you time in Autocad, it has benefits for PLAXIS as well. Because of the absence of triangulation, the PLAXIS 3D mesher can more easily create better meshes with less elements for both simple and complex projects, by using the mathematical representations of the imported objects.

The post New in PLAXIS 3D 2016: Improved Import of CAD data appeared first on Plaxis.

PLAXIS Connect can be used for updating your CodeMeter licence, to validate your installed software, and keep it up to date. Furthermore it will warn you when updates are available, and show you the latest news about our products and services. Watch the instructional movie, and find out how simple it is.

PLAXIS Connect is automatically installed with the PLAXIS 2D and PLAXIS 3D software.

The post PLAXIS Connect appeared first on Plaxis.

When using the latest PLAXIS 3D version with existing projects created in older versions and you want to modify your phases you are advised to:

1. delete the existing phases that you don’t need anymore in your new project
2. go to blue modes (Soil or Structures mode)
3. return to Staged construction mode
4. Add any required new phases

We are working on a solution for this.

The post Crash after adding phases in 3D 2016 to projects made in PLAXIS 3D AE appeared first on Plaxis.

This example demonstrates the natural frequency of a long five-storey building when subjected to free vibration and earthquake loading.

The building consists of 5 floors and a basement. It is 10 m wide and 17 m high including the basement. The total height from the ground level is 5 x 3 m = 15 m and the basement is 2 m deep. A value of 5 kN/m² is taken as the weight of the floors and the walls. The building is constructed on a clay layer of 15 m depth underlayed by a deep sand layer. In the model, 25 m of the sand layer will be considered.

This requires the Dynamics module.

The attached *.p3dlog file contains all the commands to generate the models up to calculation (without point for curves selection). With a PLAXIS VIP licence you can use the commands runner to open the *.p3dlog file and to execute all commands in one go. Without a VIP licence, you can open the *.p3dlog file with any text editor, like Notepad, and then execute the commands via the command line command by command.

The post PLAXIS 3D Tutorial 08: Free vibration and earthquake analysis of a building appeared first on Plaxis.

In this tutorial the influence of a vibrating source on its surrounding soil is studied. To reduce the calculation time, only one-quarter of the overall geometry is modelled, using symmetry boundary conditions along the lines of symmetry. The physical damping due to the viscous effects is taken into consideration via Rayleigh damping. Also, due to radial wave propagation, 'geometric damping' can be significant in attenuating the vibration.

The modelling of the boundaries is one of the key points in the dynamic calculation. 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.

This requires the Dynamics module.

The attached *.p3dlog file contains all the commands to generate the models up to calculation (without point for curves selection). With a PLAXIS VIP licence you can use the commands runner to open the *.p3dlog file and to execute all commands in one go. Without a VIP licence, you can open the *.p3dlog file with any text editor, like Notepad, and then execute the commands via the command line command by command.

The post PLAXIS 3D Tutorial 07: Dynamic analysis of a generator on an elastic foundation 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. The dam to be considered is 30 m high. The top width and the base width of the dam are 5 m and 172.5 m respectively. The dam consists of a clay core with a well graded fill at both sides. The geometry of the dam is depicted in the image below. The normal water level behind the dam is 25 m high. A situation is considered where the water level drops 20 m. The normal phreatic level at the right hand side of the dam is 10 m below ground surface. The sub-soil consists of overconsolidated silty sand.

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

The attached *.p3dlog file contains all the commands to generate the models up to calculation (without point for curves selection). With a PLAXIS VIP licence you can use the commands runner to open the *.p3dlog file and to execute all commands in one go. Without a VIP licence, you can open the *.p3dlog file with any text editor, like Notepad, and then execute the commands via the command line command by command.

The post PLAXIS 3D Tutorial 06: Rapid drawdown analysis appeared first on Plaxis.

The lining of a shield tunnel is often constructed using prefabricated concrete ring segments, which are bolted together within the tunnel boring machine to form the tunnel lining. During the erection of the tunnel lining the tunnel boring machine (TBM) remains stationary. Once a tunnel lining ring has been fully erected, excavation is resumed, until enough soil has been excavated to erect the next lining ring. As a result, the construction
process can be divided in construction stages with a length of a tunnel ring, often about 1.5 m long. In each of these stages the same steps are repeated over and over again.

In order to model this, a geometry consisting of slices each 1.5 m long can be used. The calculation consists of a number of Plastic phases, each of which models the same parts of the excavation process: the support pressure at the tunnel face needed to prevent active failure at the face, the conical shape of the TBM shield, the excavation of the soil and pore water within the TBM, the installation of the tunnel lining and the grouting of the gap between the soil and the newly installed lining. In each phase the input for the calculation phase is identical, except for its location, which will be shifted by 1.5 m each phase.

The attached *.p3dlog file contains all the commands to generate the models up to calculation (without point for curves selection). With a PLAXIS VIP licence you can use the commands runner to open the *.p3dlog file and to execute all commands in one go. Without a VIP licence, you can open the *.p3dlog file with any text editor, like Notepad, and then execute the commands via the command line command by command.

The post PLAXIS 3D Tutorial 05: Phased excavation of a shield tunnel 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 tutorial concerns the construction of a road embankment in which the mechanism described above is analysed in detail. In the analysis two new calculation options are introduced, namely a consolidation analysis and the calculation of a safety factor by means of a safety analysis (phi/c-reduction). It also involves the modelling of drains to speed up the consolidation process.

The attached *.p3dlog file contains all the commands to generate the models up to calculation (without point for curves selection). With a PLAXIS VIP licence you can use the commands runner to open the *.p3dlog file and to execute all commands in one go. Without a VIP licence, you can open the *.p3dlog file with any text editor, like Notepad, and then execute the commands via the command line command by command.

The post PLAXIS 3D Tutorial 04: Construction of a road embankment appeared first on Plaxis.

In this lesson a suction pile in an off-shore foundation will be considered. A suction pile is a hollow steel pile with a large diameter and a closed top, which is installed in the seabed by pumping water from the inside. The resulting pressure difference between the outside and the inside is the driving force behind this installation.
In this exercise, the length of the suction pile is 10 m and the diameter is 4.5 m. An anchor line is attached on the side of the pile, 7 m from the top. To avoid local failure of the pile, the thickness of the tube where the anchor line acts on the pile is increased. The soil consists of silty sand. To model undrained behaviour, an undrained stress analysis with undrained strength parameters will be performed.

This exercise will investigate the displacement of the suction pile under working load. Four different angles of the working load will be considered. The installation process itself will not be modelled.

The attached (zipped) *.p3dlog file contains all the commands to generate the models up to calculation (without point for curves selection). With a PLAXIS VIP licence you can use the commands runner to open the *.p3dlog file and to execute all commands in one go. Without a VIP licence, you can open the *.p3dlog file with any text editor, like Notepad, and then execute the commands via the command line command by command.

The post PLAXIS 3D Tutorial 03: Loading of a suction pile appeared first on Plaxis.

This lesson describes the construction of an excavation pit in soft clay and sand layers. The pit is a relatively small excavation of 12 by 20 m, excavated to a depth of 6.5 m below the surface. Struts, walings and ground anchors are used to prevent the pit to collapse. After the full excavation, an additional surface load is added on one side of the pit.

The attached (zipped) *.p3dlog file contains all the commands to generate the models up to calculation (without point for curves selection). With a PLAXIS VIP licence you can use the commands runner to open the *.p3dlog file and to execute all commands in one go. Without a VIP licence, you can open the *.p3dlog file with any text editor, like Notepad, and then execute the commands via the command line command by command.

The post PLAXIS 3D Tutorial 02: Excavation in sand appeared first on Plaxis.

In this chapter a first application of PLAXIS 3D is considered, namely the settlement of a foundation in clay. This is the first step in becoming familiar with the practical use of the program.
The general procedures for the creation of a geometry, the generation of a finite element mesh, the execution of a finite element calculation and the evaluation of the output results are described here in detail. The information provided in this chapter will be utilised in the following lessons. Therefore, it is important to complete this first lesson before attempting any further tutorial examples.

The attached (zipped) *.p3dlog files contain all the commands to generate the models up to calculation (without point for curves selection). With a PLAXIS VIP licence you can use the commands runner to open the *.p3dlog file and to execute all commands in one go. Without a VIP licence, you can open the *.p3dlog file with any text editor, like Notepad, and then execute the commands via the command line command by command.

The post PLAXIS 3D Tutorial 01: Foundation in overconsolidated clay appeared first on Plaxis.

All PLAXIS products require the CodeMeter dongle with current drivers and active licences for PLAXIS 2D and/or PLAXIS 3D in order to run.

The driver package can be used for 32-bits and 64-bits Windows.

• Local installation: install drivers on the local computer
• Network installation: install drivers on both server and local computer, see also the related article on Network installation.

Note:
When updating the drivers, it could be that the CodeMeter key is not recognized. This can be seen in the system tray: the CodeMeter icon is grey and not green. In order to make it work again: first remove the CodeMeter key, and then reboot the computer/server. Finally, when the computer/pc is rebooted, plug in the CodeMeter key in the USB port.

inactive CodeMeter system tray icon

active CodeMeter system tray icon

The post Codemeter Drivers appeared first on Plaxis.

New and improved features PLAXIS 2D 2017.00

• all applications are 64-bit only for better performance and ability to handle larger projects
• massively improved performance and memory use, particularly when dealing with huge projects
• possibility to get a separate, floating command line window
• embedded beams support grout anchor behavior
• a Python distribution is included for easier use of the remote scripting facilities
• saving of inverse analysis settings in SoilTest
• support for non-linear geogrid Elastoplastic (N-epsilon) type
• support for time-dependent geogrid Visco-elastic type
• possibility to define mesh element dimension in length units
• multiselect-on-click behavior for selecting overlapping objects of the same type
• added multiply command for features and numeric properties
• possibility to apply design approaches to Hoek-Brown soil models
• possibility to automatically attach node-to-node anchor to embedded beam
• define cross and parallel permeabilities in interface material
• support for encrypting the communications between a PLAXIS application and the scripting facilities
• model explorer groups clusters based on material assignment in Output
• added more copy options for the command line session editor
• added PyQtGraph package to the Python distribution
• added Robertson type of CPT data interpretation

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 6.00. The driver version provided with PLAXIS 2D 2017 is 6.40. Plaxis recommends to always use the latest versions.

The post PLAXIS 2D 2017.00 appeared first on Plaxis.

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