In the video we show how to set-up the model discussed in the validation report below. The validation concerns the response of a rock mass due to circular excavation in a Hoek-Brown material with a uniform in-situ stress. The initial calculation is performed with the Field stress calculation type available since 2D 2016.
In the video we show how to set-up the model discussed in the validation report below. The validation concerns the response of a rock mass due to circular excavation in a Hoek-Brown material with non-uniform in-situ stress. The initial calculation is performed with the Field stress calculation type available since 2D 2016.
In this movie we explain how to define rockbolts in the Tunnel Designer, available since 2D 2016.
This movie shows how to set-up the model used in the validation document linked below. The validation concerns a circular tunnel driven in a jointed rockmass with non-uniform in-situ stress.
This tutorial illustrates change in coupling of groundwater flow and thermal flow as a result of ground freezing. A tunnel is constructed with the use of freeze pipes. By first installing freeze pipes in the soil, the soil freezes and becomes watertight so that tunnel construction can take place. This method of construction requires a lot of energy for the cooling of the soil, so by being able to model the cooling behaviour while groundwater flow is present an optimal freezing system can be designed.
In this tutorial a tunnel with a radius of 3.0 m will be constructed in a 30 m deep soil layer. A groundwater flow from left to right is present, influencing the thermal behaviour of the soil. First the soil will be subjected to the low temperatures of the freeze pipes, and once the soil has frozen sufficiently, tunnel construction can take place. The latter is not included in this tutorial.
Because groundwater flow causes an asymmetric temperature distribution, the whole geometry needs to be modelled, where in previous examples only half of the geometry was sufficient.
Objectives:
Figure 1. Temperature distribution for a transient calculation
This exercise requires the PlaxFlow module and Termal module in order to be able to perform transient groundwater flow calculations in combination with thermal calculations.
The attached *.p2dxlog 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 *.p2dxlog file and to execute all commands in one go. Without a VIP licence, you can open the *.p2dxlog file with any text editor, like Notepad, and then execute the commands via the command line command by command.
A navigable lock is temporarily 'empty' due to maintenance. After some time there is significant increase of the air temperature, which causes thermal expansion of the inner side of the lock, while the soil-side of the concrete block remains relatively cold. This leads to backward bending of the wall and, consequently, to increased lateral stress in the soil behind the wall and increased bending moments in the wall itself.
Figure 1. Temperature distribution around the concrete lock (in magenta/red)
This example demonstrates the use of the Thermal module to analyse this kind of situations.
This exercise requires the PlaxFlow module and Termal module in order to be able to perform transient groundwater flow calculations in combination with thermal calculations.
The attached *.p2dxlog 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 *.p2dxlog file and to execute all commands in one go. Without a VIP licence, you can open the *.p2dxlog file with any text editor, like Notepad, and then execute the commands via the command line command by command.
This example demostrates the natural frequency of a 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 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.
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 attached *.p2dxlog 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 *.p2dxlog file and to execute all commands in one go. Without a VIP licence, you can open the *.p2dxlog file with any text editor, like Notepad, and then execute the commands via the command line command by command.
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 attached *.p2dxlog 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 *.p2dxlog file and to execute all commands in one go. Without a VIP licence, you can open the *.p2dxlog file with any text editor, like Notepad, and then execute the commands via the command line command by command.
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 attached *.p2dxlog 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 *.p2dxlog file and to execute all commands in one go. Without a VIP licence, you can open the *.p2dxlog file with any text editor, like Notepad, and then execute the commands via the command line command by command.
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 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 calculations in the Flow mode
The attached *.p2dxlog 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 *.p2dxlog file and to execute all commands in one go. Without a VIP licence, you can open the *.p2dxlog file with any text editor, like Notepad, and then execute the commands via the command line command by command.
In this lesson the flow around a sheetpile wall will be analyzed. The geometry model of Tutorial 3 will be used. The well feature is intruduced in this example.
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 transient groundwater flow calculations.
The attached *.p2dxlog 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 *.p2dxlog file and to execute all commands in one go. Without a VIP licence, you can open the *.p2dxlog file with any text editor, like Notepad, and then execute the commands via the command line command by command.
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 attached *.p2dxlog 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 *.p2dxlog file and to execute all commands in one go. Without a VIP licence, you can open the *.p2dxlog file with any text editor, like Notepad, and then execute the commands via the command line command by command.
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 attached *.p2dxlog 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 *.p2dxlog file and to execute all commands in one go. Without a VIP licence, you can open the *.p2dxlog file with any text editor, like Notepad, and then execute the commands via the command line command by command.
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 recalculate 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 attached *.p2dxlog 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 *.p2dxlog file and to execute all commands in one go. Without a VIP licence, you can open the *.p2dxlog file with any text editor, like Notepad, and then execute the commands via the command line command by command.
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 recalculate the Plaxis project: the results are not included to minimize the download size.
This exercise requires the VIP module in order to be able to use the Hoek-Brown material model.
The attached *.p2dxlog 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 *.p2dxlog file and to execute all commands in one go. Without a VIP licence, you can open the *.p2dxlog file with any text editor, like Notepad, and then execute the commands via the command line command by command.
PLAXIS 2D has special facilities for the generation of circular and non-circular tunnels and the simulation of a tunnel construction process. In this chapter 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.
Since PLAXIS 2D2012, the piles are modelled using the embedded pile rows.
In order to inspect the calculation results, please recalculate the Plaxis project: the results are not included to minimize the download size.
The attached *.p2dxlog 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 *.p2dxlog file and to execute all commands in one go. Without a VIP licence, you can open the *.p2dxlog file with any text editor, like Notepad, and then execute the commands via the command line command by command.
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 recalculate the Plaxis project: the results are not included to minimize the download size.
The attached *.p2dxlog 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 *.p2dxlog file and to execute all commands in one go. Without a VIP licence, you can open the *.p2dxlog file with any text editor, like Notepad, and then execute the commands via the command line command by command.
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 2D2012, PLAXIS introduces the embedded pile row feature. With this new feature, ground anchors can be modelled more realisticly compared to the older method of using a geogrid to model the grout body.
The attached *.p2dxlog 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 *.p2dxlog file and to execute all commands in one go. Without a VIP licence, you can open the *.p2dxlog file with any text editor, like Notepad, and then execute the commands via the command line command by command.
This lesson illustrates the use of PLAXIS for the analysis of submerged construction of an excavation. Most of the program features that were used in the previous chapter will be utilised here again. In addition, some new features will be used, such as the use of interfaces and anchor elements, the generation of water pressures and the use of multiple calculation phases. The new features will be described in full detail, whereas the features that were treated in the previous lesson will be described in less detail. Therefore it is suggested that the previous lesson should be completed before attempting this exercise.
This tutorial concerns the construction of an excavation close to a river. The excavation is carried out in order to construct a tunnel by the installation of prefabricated tunnel segments. The excavation is 30 m wide and the final depth is 20 m. It extends in longitudinal direction for a large distance, so that a plane strain model is applicable. The sides of the excavation are supported by 30 m long diaphragm walls, which are braced by horizontal struts at an interval of 5.0 m.
In order to inspect the calculation results, please recalculate the Plaxis project: the results are not included to minimize the download size.
The attached *.p2dxlog 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 *.p2dxlog file and to execute all commands in one go. Without a VIP licence, you can open the *.p2dxlog file with any text editor, like Notepad, and then execute the commands via the command line command by command.
In this lesson a first application is considered, namely the settlement of a circular foundation footing on sand. This is the first step in becoming familiar with the practical use of PLAXIS 2D. The general procedures for the creation of a geometry model, 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 lesson will be utilised in the later lessons. Therefore, it is important to complete this first lesson before attempting any further tutorial examples.
A circular footing with a radius of 1.0 m is placed on a sand layer of 4.0 m thickness as shown in Figure 1.1. Under the sand layer there is a stiff rock layer that extends to a large depth. The purpose of the exercise is to find the displacements and stresses in the soil caused by the load applied to the footing.
The attached *.p2dxlog 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 *.p2dxlog file and to execute all commands in one go. Without a VIP licence, you can open the *.p2dxlog file with any text editor, like Notepad, and then execute the commands via the command line command by command.