1.A sand is densified by compaction at a construction site so thatthe void ratio changes from 0.8 to 0.5. If the specific gravity ofthe soil solids is 2.7, what is the increase in the dry unit weightof the sand (in pcf and kN/m3)?
2.a) What is the meaning of ‘most efficient crosssection’ for open channels?
b) A rectangular channel has a bottomwidth = b and flow depth = y. Prove that for a given area, the mostefficient rectangular cross section is one with y = b/2.