Frequently Asked Questions
However, GALENA also allows slice boundaries to
be input at (almost) any orientation and allows the user to
specify material properties for that slice boundary. For example,
two slice boundaries may be specified manually and then
GALENA would also include other slice boundaries
automatically. The automatic slice boundaries would be sub-
parallel to the two manually specified slice boundaries. The strength assigned to automatic slice boundaries is
calculated as the average value of the material properties for the
model. In this way, a fault can be given low material properties
by using a manual slice, but the material either side of the fault
will have the properties of the model by using automatic
slices. Manual slices are defined using the SLICES command. The slices command is quite smart and will adjust itself
automatically to an exact size to fit between the failure surface
and the slope profile. For example, a long slice boundary can be
input manually and when previewed (with the preview option) its
full length is shown. However, when the model is run the length
will be truncated and only the exact length used is
shown. We believe it may be both confusing and misleading to have many
different methods of analysis all providing different answers to
the same problem. In this case, the engineer then has to decide
which result is realistic, which can be an unnecessary
complication. For circular analyses most of the methods of stability analysis
give similar answers, and the Bishop Simplified Method is widely
recognised as producing realistic results. For non-circular analyses, the Spencer method satisfies both
moment and force equilibrium conditions and normally gives a
reliable answer. The Morgenstern and Price method is similar to
Spencer's method except that it allows for a variable interslice
force angle on every slice and is theoretically more
'mathematically' correct. However, the variation in interslice
force angle is generally unknown for almost all problems and
therefore the result could in fact be less realistic using the
Morgenstern and Price method than using Spencer's method. Also,
the Morgenstern and Price method can have convergence
problems. For complex problems, the Sarma method is the only method that
allows for non-vertical slices, and separate material properties
to be specified for slice boundaries. The Sarma method can also be
used for foundation or other complex geological problems. Note that no method is 'correct' and that the stability of a
slope is independent of the method of analysis.
GALENA gives you the methods of analysis to obtain
realistic results. Major engineering and mining consultants using
GALENA include Berdal Stromme, BHP Engineering,
CMPS&F, Connel Wagner, Coteprol, Douglas Partners, Franken
Consult, GH&D, Golder Associates, Howard Humphreys, Knight
Piesold & Partners, Maunsell Geotechnical, Rust PPK, Tonkin
& Taylor, US Army Corps of Engineers, Woodward-Clyde, Works
Consultancy and Worley Consultants. GALENA was
recently selected by the United Nations Development Program for
the Mongolian Technical University in Ulaan Baatar for use in
training and setting up of a consultancy for that country's
growing engineering field. Regulatory bodies, Government departments and authorities using
GALENA include Australian Construction Services,
Water Resources and Mines departments in Australia, Hydro-Electric
and Electricity authorities in Australia, Canada, Mexico and
Nicaragua; Melbourne Water, Queensland Railways, Highway and Main
Road departments in Western Australia, Virginia, Missouri and
Washington; Indian Bureau of Mines, Central Mining Research
Institute and National Institute of Rock Mechanics in India; and
Geological Survey divisions in Britain, USA, Papua New Guinea and
Australia. GALENA is also used by the Western
Australian Mines Department to verify all open pit slopes in that
state. GALENA is being used by an increasing number of
Universities and Educational Institutions (35 to date) for
teaching and research purposes in Argentina, Australia, Austria,
Brazil, Chile, Germany, Greece, Indonesia, Italy, Macedonia,
Malaysia, Mexico, New Zealand, Poland, Serbia, Slovenija, South
Africa, Sweden, Turkey, UK, USA and Venezuela. Finally, GALENA has been reviewed by the US
Office of Surface Mining and Mine Health and Safety Authority in
Pittsburgh and they indicated to us that they prefer
GALENA to all other slope stability software they
are aware of. To date there are more than 465 GALENA users, in
50 countries around the world. Return to GALENA
Intro Page.
Q.
What is GALENA?
A.
GALENA is a comprehensive and user-friendly
Slope Stability Analysis system written by practising engineers
for engineers. GALENA was originally written for
mining applications, but has now been widely accepted as a
valuable tool for use in civil and geotechnical engineering, and
for teaching and research applications as
well.
Q.
What will GALENA run on, and what will it
output to?
A.
GALENA is a Windows based program and will
run on IBM and IBM compatible PC's running Windows 95/98 and
Windows NT version 4.0. Details...
Q.
What is the advantage of using Bishop's
method?
A.
Bishop's method is suited to most stability problems where
a circular failure surface is likely. It is easy to run and always
produces a result, since it only considers moment
equilibrium.
Q.
What is the advantage of using Spencer's
method?
A.
The Spencer method is suited to both circular and
non-circular problems and is theoretically more accurate than
Bishop's method. However, in practice, the factors of safety
determined by Spencer's method and Bishop's method for circular
failure surfaces are almost identical. In some situations it can
be difficult to get a result when using Spencer's method since the
force and moment equilibrium calculations may not always converge.
For these instances, GALENA allows for inclusion of
a tension crack of a user-defined depth to be generated
automatically.
Q.
What is the advantage of using Sarma's
method?
A.
The Sarma method is suited to more complex problems using
non-vertical slices. Slice boundary properties can be set
independently of surrounding material properties, thus allowing
modelling of discontinuities. It can even be used to simulate
foundation problems.
Q.
How are non-vertical slice boundaries generated when
using Sarma's method?
A.
GALENA will normally generate slice
boundaries for Sarma's method automatically, and will put a slice
boundary in at every point where there is a change in either slope
profile or failure surface. These slice boundaries will be drawn
approximately at right angles to the failure surface and the
failure plane.
Q.
Does GALENA use other methods of
analysis, eg. Fellenius, Corps of Engineers,
Morgenstern-Price?
A.
The design philosophy behind GALENA is to
provide engineers with tools to solve problems quickly and
efficiently, and the methods of stability analysis provided in
GALENA will enable engineers to do this.
Q.
How can pore pressures be modelled?
A.
Pore pressures can be modelled in GALENA in
several different ways:
Q.
Can pore pressures be simulated by inputting a grid of
pore pressures?
A.
Pore water pressure input from a pore pressure grid is not
included at present for the following reasons:
Q.
Can an increase in strength of clays with depth be
simulated?
A.
Yes, GALENA allows the user to specify an
increase in Cu with depth after Skempton's relationship using
plasticity index and overburden pressure. Or, effective parameters
can be specified for different layers.
Q.
What is the limit to the number of trial failure
surfaces used?
A.
There is no set limit for an analysis run, however, we
would recommend a sequential approach using say 200 trial failure
surfaces initially, then reducing the search area and trying a
further 100 surfaces, etc...
Q.
What is the RESTRAINTS command?
A.
GALENA allows the user to specify where to
search for a critical failure surface, and this is done with the
RESTRAINTS command. The most common way to do this is to specify a
restraint zone near the toe of the slope and a restraint zone
behind the crest of the slope through which the critical failure
surface is likely to pass, as well as a radius range for circular
surfaces or mid-point deflection range for non-circular
surfaces.
Q.
What is the BACK ANALYSIS command?
A.
This is a feature of GALENA which enables
the user to specify a required factor of safety (not necessarily
FOS=1.0), for which GALENA will determine the
strength required to achieve that factor of safety for the given
slope and material, and graphically display the strength
relationship.
Q.
How are GALENA data files
generated?
A.
GALENA has its own built-in smart editor
with drop-down menus, dialog and data entry boxes making it very
easy to generate a data file, and to edit data files using
GALENA's fast-edit
function.
Q.
Can output files be generated for use with other
packages, and in what formats?
A.
Yes, GALENA generates graphics and print
files for review in GALENA. The print files, and
output graphic files created by GALENA in various
formats, can be included into reports using most word processing
packages. GALENA can create HPGL, Postscript, colour
Postscript and GEM graphic files for this
purpose.
Q.
Does GALENA have a hardware security
key?
A.
No, not for copies distributed after 1 October 1996.
Previously GALENA did have a security key. With the
advent of Windows 95 and NT we decided not to use security keys in
favour of a simpler software protection system.
GALENA can still be provided with a security key on
request for those who may wish to regularly move
GALENA to notebook PCs, or may prefer security keys.
Security is designed to protect your
investment.
Q.
What detailed information is available when using
GALENA?
A.
GALENA comes with a detailed Users' Guide,
including a simple tutorial, an example of the use of all the
GALENA commands, and example data files on disk,
that will ensure you can learn GALENA
quickly.
Q.
What backup and support is available?
A.
We provide assistance to ensure GALENA will
run for you. We can be contacted by telephone, facsimile and
e-mail via the Internet for questions you may have on using
GALENA. We can also provide a service to analyse any
of your problems - our standard consulting rates would normally
apply for this work, but most problems would rarely take more than
a few hours.
Q.
Has GALENA been independently checked by
anyone?
A.
Yes, a very early version of GALENA (called
SLOPANAL2) was verified in the ACADS report in 1990. SLOPANAL2
came out very well in this report. However, it should be
emphasised that significant improvements were made to the original
program to produce GALENA and we now believe it is
the most user friendly slope stability package on the market. The
ACADS files are supplied with GALENA for users to
verify the results if they wish, and with the growing number of
users there are many more 'checks' being carried
out.
Q.
Who uses GALENA?
A.
GALENA was officially launched in February
1992. It has gained rapid approval and is being used by major
mining companies such as Hamersley Iron, Northparkes Gold, Renison
Goldfields and PosGold in Australia; BHP Minerals operations in Mt
Newman, Queensland, San Francisco and New Mexico; BHP Copper
operations in Papua New Guinea and at Escondida in Chile; Iscor,
Ashanti Gold, and Anglo American Corporation in Africa; Kaltim
Prima Coal, Batubara Bukit Asam and Mumut Copper Mining in
Indonesia; Coal Corporation of New Zealand, and more recently by
some of the larger mining companies in South America, including
operations either managed or owned by companies such as Exxon and
Placer Dome.