Question

(a) In order to stabilise a section of a proposed road on a deep soft clay layer, the vibro replacement technique is used. According to the particle size distribution of the backfill material, the following information is given:
D₅₀ = 50 mm, D₂₀ = 10 mm and D₁₀ = 0.5 mm with a trace of fine grained soil (less than 3%). Check is this soil can be used as a backfill material?
b) Explain why preloading and prefabricated vertical drains (PDV) are used in the road formation stabilisation.
c) Write a short note about the Benkelman Beam and its uses.

Answer 1