You might also want to try
http://www.fhwa.dot.gov/////////bridge/geosoft.htm where you will be able to
download
Reinforced Soil Slopes (RSS) 
Description: A computer program for the design and analysis of reinforced
soil slopes (RSS). The programs are based on FHWA manual "Reinforced Soil
Structures Volume I-Design and Construction Guidelines" (FHWA-RD-89-043).
Reinforced Slope Stability, this program analyzes and designs soil slopes
strengthened with horizontal reinforcement, as well as analyzing
unreinforced soil slopes. The analysis is performed using a two dimensional
limit equilibrium method. The program uses an extensively modified version
of the STABL computer program and guidelines for design of soil
reinforcements as stated in Elias and Christopher (1996) and Christopher et.
al. (1988 and 1990). This program uses the MS DOS operating system
As stated, this is a modified version of STABL, which was originally
developed for the FHWA in the 80's and has since passed into commercial
development and maintenance, I think at Purdue.  We acquired PCSTABL4 in the
mid-80's, and I used it exclusively for several years before switching to
Slope/W about 3 years ago.  It was a bit (a lot actually) less convenient to
use and had some limitations, required data input file creation in a text
editor, and had limitations in the variety of limit-equilibrium analyses
types (simplified Bishop and Janbu only) .  It was certainly an improvement
over manual methods!  The underlying algorithms were fundamentally in
agreement with the methods of Bishop and Janbu, it simply accelerated the
arithmetic.  
It had the advantage, however, of being usable of fairly primitive hardware.
I started using it on a 286 without a math-coprocessor, and believe it could
have been used on IBM-PC's and XT's.  It was written in FORTRAN. 
If RSS (which I have not tried) is based on STABL, I expect it would be
suitable for use simply by omitting reinforcement layers.  These had to be
treated in PCSTABL4 as tie-back loads, and I suspect RSS is an improvement
on this.
I am pretty sure that PCSTABL4 was, or is now, in the public domain, and
would have no problem e-mailing you the software, and surface mailing a copy
of the manual, if you want it.  If list members are aware that this is
otherwise, please let me know.  The manual, I will warn you, is heavily
marked up. 
The other option is to have the students prepare their own program for a
single trial surface, using spreadsheet software, which will help reinforce
the underlying methodology of each analysis type.  They can then assess the
effect of changing the trial surfaces for themselves.
Searching techniques are not beyond the capacity of most spreadsheet
applications, but I assume you are teaching a soil mechanics course, not one
in computer programming.  This will complicate the programming, and I don't
recall doing 100 or a 1000 trial surfaces in the days when these things were
done manually, and you learned to focus your trials very quickly.
I strongly recommend the SLOPE/W product if you choose to use this instead.
Speed of use is greatly improved, and I have not yet identified any
limitations it imposes on my work, insofar as analysis options which are
available.  On the other hand, I am still a bit of a Luddite when it comes
to encouraging students to use engineering software when they have yet to
grasp the underlying fundamentals.    
Let me know if I can help out with this.
Regards, Mike

Michael R. Bleakney, P. Eng.
Geotechnical Engineer
New Brunswick Department of Transportation
Design Branch
PO Box 6000
Fredericton, NB
E3B 5H1
Canada

Phone: (506)453-2674
Fax: (506)457-6714
E-mail: [log in to unmask]


 -----Original Message-----
From: 	Paul Bryden [mailto:[log in to unmask]] 
Sent:	Tuesday, October 10, 2000 10:51 AM
To:	'Buu-Long Nguyen'; engineering-geotech
Subject:	RE: [HELP] Free/shareware for slope stability

Hello Buu-Long Nguyen,

Have a look at the free SLOPE/W Student Edition on our web site at
http://www.geo-slope.com/products/student.slope.asp. With the Student
Edition you can: 

 - Analyze problems with two different soils plus a bedrock layer.
 - Describe the soil with a total unit weight (gamma), cohesion (c)
   and/or a friction angle (phi).
 - Specify pore-water pressure conditions with one piezometric line.
 - Examine circular and non-circular slip surfaces.
 - Compute factors of safety using six different methods of slices. 

Another good resource you can search is the Geotechnical and
Geoenvironmental Software Directory at http://www.ggsd.com.

Best regards,

Paul Bryden
GEO-SLOPE International Ltd.

-----Original Message-----
From: Buu-Long Nguyen [mailto:[log in to unmask]]
Sent: Tuesday, October 10, 2000 4:01 AM
To: engineering-geotech
Subject: [HELP] Free/shareware for slope stability
Importance: High


Dear forum-fellows,

Could you please advise where I can find free- or shareware for slope
stability
analysis?
I'm seaking for free/shareware with which stability of a slope consisting of
a
number of soil layers can be calculated.

Many thanks in advance!

Best regards,
Buu-Long Nguyen


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