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Features Page:
Full three-dimensional and tabular stress
analysis
- Map3D is a fully three-dimensional
boundary element program allowing for simultaneous use of both FF
(fictitious force) and DD (displacement discontinuity) element types.
- FF elements are used to define the
location of excavation surfaces and the boundaries of alternate material
zones.
- 3D alternate material zones can include materials with differing
material properties (stress state, stiffness and strength parameters)
and are thus useful for simulation of soft "schist" zones,
stiff dykes and backfilled zones.
- Map3D
Non-Linear has the capability to
simulate non-linear yielding of these 3D zones.
- DD elements are used to simulate
fractures, fault slip surfaces and tabular mining.
- DD elements can be filled with alternate materials making them useful for
simulation of fault gouge, non-linear fault slip, yielding tabular
pillars and backfilled (hyperbolic model is included) tabular zones.
- Map3D
Fault-Slip has the capability to
simulate non-linear yielding of these DD zones.
- Multi-step analysis
allows for simulation of progressive mining including backfill and
structural support placement.
- Since FF and DD elements can be used
simultaneously, complex fault slip interactions with 3D excavations can
be analyzed. This capability is also useful for studying the interaction
of fractures around boreholes or other excavation shapes.
Elastic,
non-linear, creep and thermal/fluid flow options
- Map3D is based on the assumption
of an infinite homogeneous elastic host rockmass. Non-homogeneous
features are readily added to this.
- 3D alternate material zones are added by
defining the surface of such zones using FF elements.
- Within each zone
the material can be assigned differing elastic properties, initial
stress state, and strength properties.
- In Map3D
Non-Linear
, these zones are
permitted to yield. This yielding is controlled by use of a Bingham flow
model which allows for simulation of creep and relaxation.
- Explicit time
stepping is simulated by use of the multi-step analysis feature. This is
useful for simulation of yielding pillars, abutments, structural
supports and backfilled zones.
- Fractures and slip planes are added by
defining such zones using DD elements.
- These
zones are permitted to crack, slip and yield.
- As above, each zone can be
assigned differing elastic properties, initial stress state, and
strength properties with yielding controlled by use of a Bingham flow
model. This is useful for simulation of fault slip and wedge failures.
- Map3D
Thermal-Fluid Flow has the added capability to
simultaneously solve the coupled steady state thermal or fluid flow
problem. The complete flow and temperature or head distribution is
solved. This can be directly coupled to the stress analysis through a
coefficient of thermal expansion or effective stress in the case of
fluid flow.
Fault
slip, fracture analysis and large displacement block movements
- The DD (displacement
discontinuity) elements used in Map3D are fully capable of simulating
discrete slip and crack opening.
- Faults are permitted to intersect
excavations and other faults enabling simulation of jointed rock masses
with a limited number of discrete structures.
- DD elements can be used to describe any
desired shape thus allowing one to model non-planar fractures, bending
or waving fault planes and the intersection with other similar features.
- Filling the DD elements with alternate
materials allows for simulation of fault gouge and non-linear fault slip
with complete closure control. Multi-step analysis allows for simulation
of progressive mining and fracture propagation.
- Since DD elements satisfy rigid body
motion requirements, large displacement block movements can also be
considered. This includes the simulation of blocks sliding on planes
under external or gravity loading and is useful for simulation of wedge
failures along convoluted 3D slip surfaces.
- Since FF and DD elements can be used
simultaneously, complex interactions with 3D excavations can also be
analyzed.
Simulation
of stiff dykes, weak schist zones, structural support and backfill
- Alternate material zones can be defined as either 3D
or planar features. By specifying the material in these zones to be
stiffer, softer, weaker etc., a variety of problems including stiff dykes
and weak schist zones can be modelled. Map3D Fault-Slip can simulate non-linear
yielding in planar zones. Map3D Non-Linear has the capability to
simulate non-linear yielding of these 3D zones.
- The multi-step mining feature in Map3D
permits excavation and placement of materials at any desired time in the
mining sequence. When simulating stiff support systems such as arches,
steel sets, props, thick liners, chalks, strong backfill etc., it is
necessary to model the ground movement up to the point of support
placement, then insert the support elements either in a stress/strain
free state, or with a prescribed pre-stressing. This capability of
Map3D is particularly useful for simulation of structural support
elements and backfill, and can accommodate placement, modification of
properties and subsequent removal if desired. This option has been
enabled for use with 3D FF blocks and DD planes.
Completely
self-contained CAD including DXF import and export
- Map3D has a completely self-contained CAD facility
(Map3D
Modeller). One of the keys to the ease of use is model construction using
either conventional surface elements or the built in solid modelling
technology. This permits users to build models using a series of
three-dimensional building blocks. These blocks, which can be any
desired shape or size, are used to construct excavations and accesses,
as well as to define large or irregular shaped non-homogeneous zones
(ore zones, dykes and yielding zones). All of the material outside the
model boundary is assumed to be a solid host material.
- Special features have been implemented to
allow fast construction of tabular (CAD > Build > DDLoop) and
three-dimensional (CAD > Build > FFLoop) mining shapes. The user need only
specify the perimeter of each mining step and Map3D automatically builds
the required elements. The perimeter does not necessarily have to be
planar. In fact any bounding polyhedron of three-dimensional points are
acceptable. Complex, multi-reef, non-tabular (rolling or offset) mining
is readily simulated. Intersecting faults or three-dimensional dykes can
be simulated.
- The tabular mining can be extruded into 3D
blocks then back into tabular mining if desired. This allows
construction of detailed development to be completed very quickly. Also
different parts of the model can be simulated using the tabular
approximation while details can be obtained in areas of interest by
using true 3D shapes.
- Multiple floor plans or sections can be
traced then automatically linked together into 3D zones to represent
excavations or alternate material zones.
- Wireframe mine plan outlines and
excavation geometries can be digitized from within Map3D or imported
from several sources including AutoCAD-DXF and a universal ASCII PNT
format. The user can interactively build a model comprising 3D blocks
and planes using the built in CAD capabilities of Map3D. Based on the
geometric outlines or free-hand drawing, the user picks corners of
blocks and planes to complete construction of the model. All of this is
done graphically using the comprehensive set of tools available in the
CAD interface.
- The same input data can be used for
elastic, thermal/fluid flow or non-linear analysis.
Very
large problem sizes
- One of the features that sets Map3D apart
from other stress analysis programs is its ability to handle very large
problem sizes. For small problems involving only a few excavations and
perhaps a single intersecting fault, models limited to 10000 nodes can
provide results with reasonable accuracy. However, it is not uncommon to
encounter problems with hundreds, or even thousands of components
(including excavation surfaces, alternate material zone boundaries and
intersecting faults). For such models, accurate results can only be
obtained for model sizes approaching 100000 nodes or more.
- Map3D is currently setup to accommodate
problems with a maximum of 333333 nodes, i.e. 1,000,000 degrees of
freedom (it can be configured for larger
models if required). This is accomplished by use of matrix lumping.
Through analysis of the geometric relationships between various parts of
the model, sections of the coefficient matrix are lumped together thus
reducing the matrix size. In physical terms this means that finely
discretized zones that are far apart do not need to be represented in
detail and hence are candidates for lumping. The amount of lumping that
is permitted is controlled by user specified parameters thus easily
allowing this feature to be limited or completely disabled if desired.
- In a typical boundary element model with n
nodes, a coefficient matrix is generated with 3 degrees of freedom per
node. Since all elements influence one another, the coefficient matrix
is of size 3n x 3n =
9n² coefficients.
Allowing 4 bytes for each coefficient, problems with 100000 nodes would
require a massive 360 GB of storage without matrix lumping. Even if you
had this storage capacity, it would take too long to solve such a
matrix.
- The matrix lumping procedures in Map3D can
reduce storage requirements by 100 fold or more for large problems
bringing our 100000 node problem down to a much more reasonable size on
the order of 3.6 GB, a readily solvable size. In addition,
discretization can be optimized by setting a few control parameters to
automatically concentrate elements at locations of interest. These
capabilities give Map3D the unique ability to solve realistic size
problems on a desktop computer.
Boolean
intersection solid model building
- A model comprises one or more connected or
unconnected blocks and/or planes that can be mined and filled in a
specified sequence. Surfaces of blocks and planes are subsequently
discretized into a number of boundary elements by the program. Extensive
error checking assists the user in identifying whether the geometry is
topographically valid or not.
- Map3D automatically builds intersections
between excavations, faults and multiple material zones. By coupling
this capability with the built-in Boolean operations, complex multi-step
mining sequences can be constructed with ease. Intersecting faults or
three-dimensional dykes can be simulated.
GIS graphics
database - Seismic
display and analysis
- This option (Map3D Modeller) enables visualization of point
data. Points can be displayed as light source shaded spheres with
diameter and/or colour varying as magnitude.
Each point can be tagged with a series of numeric values (e.g. colour,
magnitude, orientation etc.) and a text message. Upon clicking on a
point, the location, magnitude and text message are displayed on the
status bar. This feature can be used to display a database of useful
geologic information such as grade, rockmass quality etc.
- Point data can be contoured on a plane to
display density etc. A linear regression routine is included for plane
fitting to the data.
Fast OpenGL
graphics
- Map3D features fast, accurate graphics
display through the implementation of OpenGL.
- For optimal performance you will need a
graphics adapter that supports 3D T&L (translation and lighting)
with on board hardware. An OpenGL driver must be installed. Users should
see approximately 100 fold display rate increase over non-hardware
assisted displays.
- For user's without T&L graphics
hardware, Windows can emulate OpenGL functionality through software
emulation. Even though there will be no increase in display rate, the
graphics display will be more accurate due to z-buffer hidden surface
removal.
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