|
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.
|