Methods of Constructing Roads in Marshy Areas:
The following methods are adopted for constructing roads in marshy areas:
(a) Removal of soft soil and replacement with good soil.
(b) Displacement of the soft soil by constructing the embankment and blasting the soft soil, such that the embankment displaces and occupies the space occupied by the soft soil.
(c) By constructing the embankment in stages, allowing settlement to take place, and if necessary to construct the embankment to a level above the designed level, and removing the excess material after full settlement has taken place.
(d) By providing vertical sand drains (0.4-0.6 m dia) which will facilitate the upward movement of water from the underlying saturated soil and drain it away. Figure gives a typical layout of sand drains.
Figure: Vertical Sand Drains