There are three methods of slope stabilizations. Physical, chemical and biological.
you can down load the publication on slope stability and soil fertility published in different journals including Environmental Management from my profile.
It is high time to visualize the slope stability status evaluation or estimation based on multivariate method. Concrete researches and established methods are put forward by esteemed scientists but I feel to share this state way that slope stability status, stability improvement, stability risk likely to come after excavations should be dealt with area -specific, time-specific, climate & weather -specific, geological -formation specific etc. and combinations of method may be fruitful for results.
This should at least help you to think about what the issues are. Most work in recent years has not been on methods of analysis, so much as on ways of finding critical surfaces. There has also been interesting work done using finite element approaches to guess pressure distributions to enable otherwise 'traditional' analyses. But beware - the more complex the information that goes into an analysis, the more likely it is that you will be misled about the accuracy of what comes out. Methods which rely on estimates of stiffness may be very susceptible to variations in those values; almost any method should take into account how the slope has been formed, and this is almost never accounted for.
Bishop's Simplified Method is still the best for circular failure surfaces, as the assumptions it depends upon are simple and reasonable, and it is easily adapted for localised surcharge or soil reinforcement. Care needs to be taken with so-called 'rigorous' methods, especially if the solution comes from adjustments to obtain moment equilibrium of each slice, because this would be using something very secondary and imprecise (just a guess, really) to get the critical answer, is the slope going to be safe or not?
There are many methods around which might be quite clever from an academic point of view, but not from a practical point of view. I thought long and hard before developing and publishing my own method, but I am convinced it is realistic.
Article Displacement based multiple wedge slope stability analysis
For increasing stability of slopes against deep seated failure, I prefer finding out ten most critical surfaces (factor of safety less than 1.0) and the design geotextile layout using a spreadsheet so that FOS is more than 1.2
Abdul, that's fine, but it's worth making sure that readers understand that the reinforcement needs to extend far enough back to reach surfaces with a factor of just less than 1.2, otherwise your slope won't have the margin of safety you are looking for. So you need to find the surfaces with a factor of 1.2, and make sure the reinforcement which is strong enough for the
Paul, the XSTABL software developed at the Purdue University is quite handy for the purpose. It gives you 100 low FoS surfaces of different extents. Deep seated surfaces can also be identified easily. Therefore, with careful judgment ( as yo mentioned), a solid reinforcement layout may be obtained. The final layoutmay be checked again for stability..
the modern slope analyses are based on numerical modelling. These methods have the possibility to study also the conditions of in depth strains of the slope and to monitor the evolution of the phenomenon. Best regards
If you are looking for ideas for future phd theses or research projects, here are a few thoughts:
1. The method of blocks is ok only if you want to do a 3d stability analysis, otherwise, in my humble opinion it is rather obsolete since there are a lot of unconservative simplifications such as the full mobilization of the shearing strength over the failure surface, the indeformability of the slices and so on
2. If you are interested in the stability of a riprap facing of a riverbank or embankment, the last fashion is to use discrete element method, case in which it is very nicely put in evidence the difference between internal friction angle and the angle of repose
3. In case you interested in propagation analysis of a landslide, my recommendation is to go ahead with Euler-Lagrange coupling (CEL).
4. Last, but not least simple FEM analyses in various hypotheses could do the trick ( you may elaborate on pore pressure build-up or fancier constitutive models to take into account things like anisotropy, strong dilatancy and so on).
Jibson, R.W. (2011). Methods for assessing the stability of slopes during earthquakes-A retrospective. Soil Dynamics and Earthquake Engineering, 91, 209-218.