The problem with this site is that in the past there was a large-scale landslide. So the rock, (schist) has a very mixed-up character, and even after drilling the site it is hard to say where we may encounter in-place bedrock. Usually we find a slide plane, but at this site there was no distinguishable slide plane. The site is too narrow for a re-alignment; we have considered a wall but cost is a factor. The site is a fill slope failure that extends for approximately 60m. Thanks for your reply.