Constructing Formation for Road:

Testing of clay available at site would tell whether cutting is necessary and to the extent it is necessary. Even if clay at site is bad cutting need not be very deep.
Depending on type and speed of traffic depth of cutting can be decided. After necessary depth is reached lower portion of road should be filled with the best clay available to keep cost of construction low. Filling shall be in layers (generally 150 to 200 mm). Every layer should be compacted using road roller as per engineering practice. Plenty of water should be used in each of the layers before and during compacting earth in formation. Water ensures highest compaction. Higher the compaction higher is the strength of road to bear traffic at desired speed. While preparing and finalising formation care should be taken to achieve desired slope in required direction. This saves material cost of upper layers of road.  Proper formation is 50% of work done. Importance of formation should not be neglected. Once formation is prepared and dried it should be rolled to ensure that proper slope is achieved.