Requirements of Highway Drainage System
ans:The followings are the basic Requirements of Highway Drainage System
i) The surtace water from the carriageway and shoulder should effectively be drained off without allowing it to percolate to subgrade
ii) The surface water from the adjoining' land should be prevented from entering the roadway.
(iii) The side drain should have sufficient capacity and longitudinal slope to cary
away all the surface water collected.
(iv) Flow of surface water across the road and shoulders and along slopes should not cause formation of cross ruts or erosion.
(V) Seepage and other sources of under ground water should be drained off by the
subsurface drainage system.
(vi) Highest level of ground water table should be kept well below the level of
Subgrade, preferably by atleast 1.2 m.
(vii) In waterlogged areas special precautions.should be taken, especially if detrimental salts are present or if flooding is likely to occur.
