Plaxis

SOFTWARE > PLAXIS > Plaxis 3D Foundation

twoplustraining01 — Fri, 13 Mar 2009 03:21:38 +0000

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SOFTWARE > PLAXIS > Plaxis 3D Foundation

twoplustraining01 — Fri, 13 Mar 2009 03:18:37 +0000

[ Requirement ]

Minimum Hardware Requirements

Pentium processor, 2.0 Ghz.
512 MB RAM (more is recommended)
Free harddisk space 600 MB
Screen resolution min. 1024×768
Windows® NT 4.0; Windows® 2000; Windows® XP Professional

SOFTWARE > PLAXIS > Plaxis 3D Foundation

twoplustraining01 — Fri, 13 Mar 2009 03:16:50 +0000

[ Features ]

PLAXIS 3D Foundation Features

คำ สั่งทั่วไปของโปรแกรม Plaxis 3D Foundation ที่ใช้ในการวิเคราะห์งานฐานรากอาคารเสาเข็ม (Pile) ขนาดใหญ่ ที่่นิยมใช้กันมากที่สุดทั่วโลก

Input features

GRAPHICAL INPUT OF PROJECTS

A project geometry is modelled using a top view approach. The input of soil data, structures, construction stages, loads and boundary conditions is based on convenient CAD drawing procedures, which allows for a detailed and accurate modelling of the major geometry. From this geometry a 3D finite element mesh is generated.

BORE HOLES

Soil layers are defined by means of bore holes. Multiple bore holes can be placed in the geometry to define a non-horizontal soil stratigraphy or an inclined ground surface. Plaxis automatically interpolates layer and ground surface positions in between the bore holes.

WORK PLANES

Structures are defined in horizontal work planes. Multiple work planes can be defined to create complex foundations, multi-storey basements and relevant parts of the upper structure.

AUTOMATIC MESH GENERATION

The Plaxis 3D Foundation program allows for an automatic generation of unstructured 2D finite element meshes based on the top view. The 2D Mesh generator is a special version of the Triangle generator. There are options for global and local mesh refinement. From this 2D mesh, a 3D mesh is automatically generated, taking into account the soil stratigraphy and structure levels as defined in the bore holes and work planes.

VOLUME ELEMENTS

Quadratic 15-node wedge elements are available to model the deformations and stresses in the soil. Due to non-horizontal soil stratigraphy, these elements may degenerate once to 13-node volume elements or twice to 10-node tetrahedral elements.

BEAMS

Foundations may involve structural objects like walls, floors and beams. A special type of beam element can be used to model slender one-dimensional objects with a significant flexural rigidity. The stiffness of these elements is defined using elastic stiffness properties or non-linear elastic deformation curves.

WALLS AND FLOORS

Special plate elements can be used to model raft foundations, basements, walls and floors of buildings, as well as other parts of structures. The behaviour of these elements is defined using elastic stiffness properties or non-linear elastic deformation curves (M-ê and N-å diagrams).

INTERFACES

These joint elements are automatically added to walls to allow for a proper modelling of soil-structure interaction. Interfaces may be used to simulate, for example, the thin zone of intensely shearing material at the contact between a wall and the surrounding soil. Values of interface friction angle and adhesion that are not necessarily the same as the friction angle and cohesion of the surrounding soil and may be assigned seperately to these elements.

PILES

Circular and square piles can be defined using a pile designer. Solid piles are composed of volume elements whereas hollow piles are composed of wall elements. Pile-soil interaction can be modelled using interfaces around the pile.

LOADS

Plaxis 3D Foundation allows for various types of loads (point loads, line loads, distributed loads) that could be applied in the model. Different loads and load levels can be activated independently in each construction stage. Soil Behaviour:

Soil behaviour

MOHR-COULOMB MODEL

This robust and simple non-linear model is based on soil parameters that are known in most practical situations. Not all non-linear features of soil behaviour are included in this model, however. The Mohr-Coulomb model may be used to compute realistic bearing capacities and collapse loads of footings, as well as other applications in which the failure behaviour of the soil plays a dominant role.

HARDENING SOIL MODEL

As a general second-order model, an elastoplastic type of hyperbolic model is available, which is called the Hardening Soil model. This model allows for plastic compaction (cap hardening) as well as plastic shearing due to deviatoric loading (friction hardening). In comparison with the Mohr-Coulomb model the unloading behaviour of the soil is better taken into account. The Hardening Soil model may be used to calculate realistic pressures below basements and raft foundations and behind soil retaining structures. More detailed information on this model can be found in the Material Models Manual.

STRUCTURAL BEHAVIOUR

Structural behaviour may be defined as linear elastic material orthotropy or as non-linear elastic force-deformation curves. This applies to beams, walls, floors and springs. Geometric orthotrophy of plates with a particular profile can also be emulated to a certain extent.

STEADY-STATE PORE PRESSURE

Complex pore pressure distributions may be generated on the basis of the input of water levels or pore pressure distributions in the bore holes. Plaxis 3D Foundation is a finite element package intended for the three-dimensional deformation analysis of foundation structures. Foundations form the interaction between an upper structure and the soil. Settlements depend on local soil conditions and on the construction method. Especially for pile-raft foundations there is an important interplay between the pile, the raft and the soil to support the forces from the upper structure. In this interplay deformations are a key factor. Such a situation can only be analysed effectively by means of three-dimensional finite element calculations in which proper models are incorporated to simulate soil behaviour and soil-structure interaction. The Plaxis 3D Foundation program offers these facilities. A brief summary of the most important features is presented below.

EXCESS PORE PRESSURE

Plaxis distinguishes between drained and undrained soils to model permeable sands as well as almost impermeable clays. Excess pore pressures are computed when undrained soil layers are subjected to loading. Calculation Features:

Calculation features

AUTOMATIC LOAD STEPPING

The Plaxis 3D Foundation program can be run in an automatic step-size selection mode. This avoids the need for users to select suitable load increments for non-linear calculations by themselves and it guarantees an efficient and robust calculation process.

ARC-LENGTH CONTROL

This feature enables accurate computations of collapse loads and failure mechanisms to be carried out. In conventional load-controlled calculations the iterative procedure breaks down as soon as the load is increased beyond the peak load. With arc-length control, however, the applied load is scaled down to capture the peak load and any residual load.

STAGED CONSTRUCTION:

This Plaxis feature enables a realistic simulation of construction and excavation processes by activating and deactivating clusters of elements, application of loads, changing of water pressure distributions, etc. This procedure allows for a realistic assessment of stresses and displacements as caused, for example, by the construction and loading of a foundation.

PREVIEW OPTION

A convenient preview option is available to check model and calculation settings in a graphical 3D environment. Since 3D calculations can be quite time consuming, it is important to check the model carefully before starting the calculation process.

Output features

The Plaxis postprocessor has enhanced 3D graphical features for displaying computational results. Exact values of displacements, stresses, strains and structural forces can be obtained from the output tables. Plots and tables can be send to output devices or to the Windows®‚ clipboard to export them to other software. In addition to the 2D version of Plaxis the following output features are available in Plaxis 3D Foundation:

PARTIAL GEOMETRY

To enhance the ‘inside’ visualisation of a 3D model, parts of the geometry can be selected as transparent.

VIEW OPTIONS

By default, a 3D model in the output program is presented in perspective view, and can be freely oriented using the arrow keys. In workplanes the x-y plane can be viewed. In addition, cross sections can be defined to view the output in two dimensions, perpendicular to the x-y plane.

SOFTWARE > PLAXIS > Plaxis 3D Foundation

twoplustraining01 — Fri, 13 Mar 2009 03:14:23 +0000

[ Overview ]

Plaxis 3D Foundation V 2.2

โปรแกรม วิเคราะห์ออกแบบเสาเข็มแบบ 3 มิติ สำหรับวิศวกรฐานราก วิศวกรงานดิน และวิศวกรธรณี สำหรับการวิเคราะห์ออกแบบฐานรากอาคารขนาดใหญ่โดยเฉพาะ

Plaxis 3D Foundation is a finite element package intended for the three-dimensional deformation analysis of foundation structures.

Foundations form the interaction between an upper structure and the soil. Settlements depend on local soil conditions and on the construction method. Especially for pile-raft foundations there is an important interplay between the pile, the raft and the soil to support the forces from the upper structure. In this interplay deformations are a key factor. Such a situation can only be analysed effectively by means of three-dimensional finite element calculations in which proper models are incorporated to simulate soil behaviour and soil-structure interaction.

SOFTWARE > PLAXIS > Plaxis 3D Tunnel

twoplustraining01 — Fri, 13 Mar 2009 03:10:24 +0000

[ Gallery ]

SOFTWARE > PLAXIS > Plaxis 3D Tunnel

twoplustraining01 — Fri, 13 Mar 2009 03:07:06 +0000

[ Requirement ]

Minimal Hardware Requirements

โปรแกรม Plaxis 3D Tunnel ต้องการคุฯสมบัติฮาร์ดแวร์ที่ใช้รันโปรแกรมอย่างน้อยดังนี้

Pentium processor
256 MB RAM
Free harddisk space 1 GB (1024 MB)
Screen resolution min. 800×600
Windows® NT 4.0; Windows® 2000; Windows® XP Professional

SOFTWARE > PLAXIS > Plaxis 3D Tunnel

twoplustraining01 — Fri, 13 Mar 2009 03:03:51 +0000

[ Features ]

Plaxis 3D Tunnel Features

คำ สั่งการใช้งานทั่วไปโปรแกรมวิศวกรรมธรณี (Geo Technical Engineering) 3D ที่วิศวกรนิยมใช้กันมากที่สุดทั่วโลก สำหรับงานวิเคราะห์ออกแบบก่อสร้างอุโมงค์โดยเฉพาะ เช่น อุโมงค์รถไฟฟ้าใต้ดิน (MRTA Tunnel) เป็นต้นInput features

Graphical input of geometry models

The input of soil layers, structures, construction stages, loads and boundary conditions is based on the same convenient drawing procedures (CAD) as the Plaxis 2D version 8, which allows for detailed and accurate modelling of realistic situations. From the geometry model a 2D and 3D finite element mesh is generated automatically.

Automatic mesh generation

Plaxis allows for fully automatic generation of (2D) unstructured finite element meshes with options for global and local mesh refinement.

Updated mesh

This option allows the analysis of large deformation problems. Typical applications, where updated mesh analyses may be necessary, include the analysis of reinforced soil structures, the analysis of large offshore footing collapse problems and the study of problems where soils are soft and large deformations occur.

Creation of the 3D model

The 3D model is created simply by linear extension of the mesh in z-direction. The user can specify the number and thickness of cross section planes (z-planes). Two successive z-planes form a slice. The previously generated 2D mesh is repeated at each z-plane. The 3D mesh is created by connecting the corners of the 2D triangular elements to the corresponding points of the corresponding elements in the next z-plane. In this way, a 3D mesh composed of thousands of 15-node wedge elements is created.

High-order elements

The 15-node wedge element is composed of 6-node triangles in x-y-direction and 8-node quadrilaterals in z-direction. This type of volume element for soil behaviour gives a second-order interpolation for displacements and the integration involves six stress points. The accuracy of the 15-node wedge elements in a 3D analysis is comparable with the 6-node triangular element in a 2D Plaxis analysis.

Tunnels

Plaxis 3D Tunnel offers improved and extended options to create circular and non-circular tunnels composed of arcs, straight lines and corners. Plates and interfaces may be added to model the tunnel lining and the interaction with the surrounding soil. Fully isoparametric elements are used to model the curved boundaries within the mesh. Different practical methods are implemented to analyse the deformations that occur due to the construction of the tunnel. Two commonly used types of tunnels have predefined settings.

Bored tunnels

A bored tunnel is circular and therefore allows for the input of only one radius. A homogeneous and continuous slender shell (plate) can be added to the full tunnel cross section. It is possible to add a thick and massive lining that is composed of volume elements rather than plates. To simulate volume loss during the construction of the Bored Tunnel, a contraction or volume strain can be applied.

NATM Tunnel

The creation of any tunnel shape is possible. Shells (discontinuous plates) can be added to the outer contour to simulate tunnel linings composed of more than one lining layer or sandwich structures. The properties of the shell, as contained in plate data sets, need to be assigned to each shell section individually. This enables the use of different data sets for individual shell sections. A thick and massive lining that is composed of volume elements rather than plates can also be added. When defining a calculation phase in the framework of Staged Construction, each section can be (de)activated individually. A volume strain can be applied to each section seperately to model a volume loss.

Z-planes and slices

Tab sheets for each individual Z-plane or slice have been included in Plaxis 3D Tunnel Version 2. This facility allows the user to specify different water boundary conditions at each plane. The boundary conditions at the slice surfaces between successive planes are linearly interpolated by the program. Also, individual slices can be selected and defined as dry. It is possible to tilt the full model in z-direction to simulate a dipping of the tunnel.

Loads

A convenient option is the possibility to (de)activate and change input values of loads per z-plane or per slice in a Staged Construction phase. In this way unlimited load combinations can be made.

Z-loads

Z-loads are loads normal to a cluster in a vertical cross section. This type of loads can be applied in the framework of Staged Construction in individual vertical cross sections of the 3D model. Z-loads can be used, for example, to analyse the tunnel heading stability.

Distributed loads

Appear as line loads in the cross section model, but in the full 3D model they can be used both as line loads on individual vertical cross sections (z-planes) as well as real distributes loads on volume sections (slices).

Point loads

appear as point forces in the cross section model, but in the full 3D model they can be used both as point loads on individual vertical cross sections as well as line loads on volume sections.

Structural elements

The Plaxis 3D Tunnel offers a number of special elements that are dedicated to model typical structural objects. These elements are to be used in the out-of-plane direction (z-direction).

Plates

Special plate elements are used to model the bending of tunnel linings, shells, retaining walls and other slender structures. The behaviour of these elements is defined using a flexural rigidity, an axial stiffness and an ultimate bending moment. A plastic hinge may develop for elastoplastic plates, as soon as the ultimate moment is mobilised. Plates may be used together with interfaces to perform realistic analyses of tunnel projects and other geotechnical applications.

Screens (interface elements)

Interface elements in Plaxis 3D Tunnel Version 2, in addition to their existing functionalities, can be used to simulate an impermeable screen. An active interface element is fully impermeable (separation of head degrees-of-freedom of node pairs). An inactive screen is fully permeable (coupling of head degrees-of-freedom of node pairs).

Closed flow boundary

A closed flow boundary is an object that can be placed at the boundary of the geometry model to ensure that flow across this boundary will not occur.

Anchors

Elastoplastic spring elements are used to model anchors and struts. The behaviour of these elements is defined using an axial stiffness and a maximum force. A special option exists for the analyses of pre-stressed (ground) anchors and excavation supports.

Geogrids

Geogrids are often used for the construction of reinforced embankments or retaining soil structures. They can be simulated in Plaxis by the use of special tension elements. It is often convenient to combine these elements with interfaces to model the interaction with the surrounding soil.

Interfaces

These joint elements are needed for calculations involving soil-structure interaction. They may be used to simulate the thin zone of intensely shearing material around tunnel linings or at the contact of footings and retaining walls. Values of interface friction angle and adhesion, that are not necessarily the same as the friction angle and cohesion of the surrounding soil, may be assigned to these elements.

Soil behaviour

Advanced soil models

In the Plaxis 3D Tunnel Version 2 the following soil models are available: Linear elastic, Mohr-Coulomb, Hardening Soil and Soft Soil Creep model. In addition to these soil models an anistropic model for rock is offered: The Jointed Rock model: This is an anistropic elasto-plastic model where plastic shearing can only occur in a limited number of shearing directions. This model can be used to simulate the behaviour of stratified or jointed rock.

Calculation features

The Calculations program considers only deformation analyses and can only perform Plastic calculations. An efficient and robust iterative solution procedure is used to solve large sets of equations in short time using a minimum amount of RAM.

Plastic calculation

In a plastic calculation, load multipliers are used to activate: prescribed loads (point loads, distributed loads), prescribed displacements and soil weight. A special feature exists for the simulation of a construction process.

Staged construction

Staged construction is a very versatile type of loading input and enables an accurate and realistic simulation of various loading, construction and excavation processes. In this special Plaxis feature it is possible to:

Change the geometry configuration by de-activating or re-activating volume clusters or structural objects as created in the geometry input to simulate for instance the building process of a tunnel or an excavation.
Change the load configuration by de-activating or re-activating loads and prescribed displacements as created in the geometry input. For example z-loads can be applied to analyse the tunnel heading stability.
Enter an internal pressure in volume clusters. This option may be used to simulate mechanical processes that result in artificial pressures in the soil, such as compensation grouting.
Apply a volume strain to a volume cluster in order to simulate processes such as compensation grouting.
Reassignment of material data sets to simulate for instance soil improvements, i.e. removing ‘soft’ soil and replacing it with ‘reinforced’ soil.
Change the water pressure distribution in the geometry.

Copy option

This useful Plaxis 3D Tunnel option enables easy copying of staged construction settings from a slice or a plane to another slice or plane. Copying can also be done for a group of slices or planes.

Consolidation

This feature enables the calculation of the generation and dissipation of excess pore pressures as a result of sudden application of external loads on a wet soil mass. Plaxis 3D Tunnel provides automatic time stepping procedures, which make the analysis robust and easy-to-use.

Steady state groundwater flow

This feature enables the generation of pore pressures as a result of groundwater flow. By adding this feature, the user will be able to generate pore pressures due to hydrostatic phreatic levels (the existing feature) or groundwater flow. Groundwater heads can be conveniently specified at boundary lines of the front plane. The results of the groundwater flow calculation include also total head distribution and Darcy flow (directions and magnitudes).

Top view

To easily define calculation phases in staged construction, a top view of the model can be shown, in which z-planes and slices can be selected interactively.

3D inspection view

The 3D model can be visualised from any angle and rotated freely in the staged construction mode to inspect the selections made.

Output features

The Plaxis post-processor has enhanced graphical features for displaying computational results. Such as displacements, stresses, strains, distributions of the groundwater heads, (excess) pore pressures. And Darcy flow. Values of these quantities can be obtained from the output tables. Plots and tables can be send to output devices or to the Windows‚ clipboard to export them to other software.

Partial geometry

To enhance the ‘inside’ visualisation of a 3D model, parts of the geometry can be selected

SOFTWARE > PLAXIS > Plaxis 3D Tunnel

twoplustraining01 — Fri, 13 Mar 2009 02:58:18 +0000

[ Overview ]

PLAXIS 3D Tunnel V 2.4

Plaxis 3D Tunnel เป็น โปรแกรมสำหรับการวิเคราะห์การเปลี่ยนรูปและเสถียรภาพแบบ 3 มิติด้าน geotechnical engineering ด้วยวิธี finite element สำหรับงานอุโมงค์ใต้ดินโดยเฉพาะ เช่น อุโมงค์ส่งน้ำ อุโมงค์รถไฟฟ้าใต้ดิน

Geotechnical applications require advanced constitutive models for the simulation of the non-linear, time-dependent and anisotropic behaviour of soils and rock. In addition, since soil is a multi-phase material, special procedures are required to deal with hydrostatic and non-hydrostatic pore pressures in the soil. Although the modelling of the soil itself is an important issue, many tunnel projects involve the modelling of structures and the interaction between the structures and the soil.

โปรแกรมที่ได้รับความนิยมสำหรับการวิเคราะห์งานดินให้ใกล้เคียงพฤติกรรมจริงมากที่สุด

SOFTWARE > PLAXIS > Plaxis Plaxflow

twoplustraining01 — Fri, 13 Mar 2009 02:51:34 +0000

[ Gallery ]

SOFTWARE > PLAXIS > Plaxis Plaxflow

twoplustraining01 — Fri, 13 Mar 2009 02:37:02 +0000

[ Requirement ]
Minimal Hardware Requirements

Pentium processor, 500 Mhz
256 MB RAM
Free harddisk space 560 MB
Screen resolution min. 800×600
Windows® NT 4.0; Windows® 2000; Windows® XP Professional