Four statements S1 to S4 connected to soil behaviour are given.

S1: Permeability of coarse grained soil is inversely proportional to square of the specific surface at a given porosity.

S2: Consolidation is a function of total stress.

S3: For a fully saturated soil the pore pressure parameter is equal to zero.

S4: Terzaghi’s theory of consolidation considers only primary consolidation.

Which of the above statements is/are correct?