Guys, just to make things clear.
From the OP question:
nagatalluri said:
Can you please suggest a geophysical method for evaluation of slope stability
I answered NO, in relation to the choice of the input geotechnical parameters.
Of course geophysical investigation can be and is advantageously used to investigate wide areas and define the landslide mass in relation to borehole soundings with an economic optimization. I agree on that.
The use of various methods can be tricky though. MASW is accurate only in the surface layers, then the reliability drops dramatically, depending upon the layering. if there is a contrast of impedance (rigidity contrast, rigid layer underneath a soft layer) The energy of surface waves is mostly reflected so no way we can accurately predict what's underneath the contrast.
REMI tends to be more accurate in deeper layers
Refraction is pretty good until there are no velocity inversions, which the method ignores. Also in refraction energy is dissipated soon so we need a dense arrangement of survey lines, 3D tomographic refraction being the best, at a co$t.
Nakamura microtremors are pretty economical with the right instrumentation but are not carried out everywhere I don't know even if in Japan, the birthplace of Nakamura, they are being routinely carried out.
Nagatalluri, I would suggest you read the linked article, which is a pretty good review. Also, you might want to consult a credible service company explaining clearly your specific needs, the conditions on the terrain (steepiness is also a factor) and what they can do for you.
It is much different if there is a shallow bedrock or competent layer or if there is not any. In the latter case, geophysical investigation may not always yield credible or useful results.