What are the procedure for road construction on unsuitable subgrade

Hi,

If the subgrade is unsuitable for road construction then replace that subgrade with a suitable type of subgrade that having a good bearing capacity and ability to resist an applied load by vehicles.

there are various techniques to increase the bearing capacity of a suitable subgrade and make it suitable for use.

Refer IRC 002, IRC 064:1990 for various methods.

following are some methods are described briefly for stabilization of the unsuitable subgrade

1. Removal/replacement of fills.
2. Traditional compaction methods
3. Uses of mechanical stabilization Techniques
4. Use chemical stabilization