Slope Stability Software Design to BS 8006

[farqy]

I am looking to find a good slope stability package which allows modelling of complex geometry and geology, and a variety of remediation measures from soil nails to geosynthetics, I am aware that there are plenty available, but does anyone know of a package that is designed to or complies fully with BS 8006.

I have pulled a couple of packages apart (including GGU-Stability) to find that the partial factors are NOT applied exactly the same as BS 8006.

Can anyone provide me with some assistance?

Cheers

 

[MSEMan]

Talren V4 will give very good solutions and is probably the best software on the market for the general analysis of slope/reinforced wall stability. Building the model is a bit of a pain but you can analyse different stages of construction, and cases (partial factors adjusted for each case) within a single model.

With respect to your specific question regarding BS8006 - Talren does not adopt a log spiral analysis although it does have a facility whereby both tension and shear in the nail are adopted. That being said log spirals are just a refinement of classical limit equilibrium methods and talren has plenty of options for finding critical surfaces.

Another really useful feature of talren is the ability to model as many different types of reinforcements in same section as you wish. So if you want to use nails in a section of cut and geogrids in a section of wall that is easy to do without have to use "equivalents".

We did a job where we were building MSE walls at the toe of a slope with the upper section nailed back and the analysis was straightforward using Talren.

The downsides of talren are that it is quite expensive (about £4000 in UK) and it won't decide design features for you. In other words you have be expereinced enough to have a pretty good idea what you think will work be fore you set off building the model.

 

[Myoho]

There is not one piece of software on the market that will be able to design soil nails properly. Geotextiles maybe but not soil nails.

The problem is that most software is plane frame 1.0m out of plane. For example when you draw a soil nail into the slope that you want to stabilise, the computer models it like a sheet 1.0m wide (1.0m out of plane) with the equivalent properties to a cylindrical shaped soil nail.

This causes many limitations, one being that if you imagine the stresses developing around a soil nail (in x-section ie a circle) you get vertical stresses on the top and bottom of the circle, horizontal stresses on the sides and stresses varying between vertical and horizontal everywhere else.

But as the software models the nail as a sheet the stresses encompasing the sheet are vertical stresses only. Giving you a higher factor of safety than in reality.

But do not be disheartened, there is software being developed which can model soil nails in 3D, such as Plaxis 3D foundations and tunelling.

The software I would recommend is SlopeW V6, Plaxis V8 and Wallap V5. If you have those 3 pieces of software you can design vitually any problem.