1. How do you lay the foundation of the road?
or What are the process of road foundation?
Before constructing the road, planners must decide and determine the route for the road. After that, the suitability of the soils in the area must be checked and examined. It is done to find out how much earth (soil) will be required to move from the site and what quantities of surfacing or refilling materials will be needed. In other words, site should be excavated and unsuitable soil should be replaced. In order to do that various machines can be used depending on the depth of the cut and how much space is at the given site. Next, final compacting is done with the roller until it is firm. This completes the sub-grade. Then, a sub-base layer- normally composed of granular material, is added depending on what thickness of concrete is to be laid. Here, we need to be careful. The material should be suitable so that water drains easily. This layer must be compacted with a roller carefully so that density is uniform all over the road. Finally, these layers must be sealed either with a sealing coat of tar or with rolls of waterproof paper. It completes the process of road making.
2. Why are surveys necessary? Explain four main reasons.
In planning a road extensive preliminary survey must be carried out. First, the main reason behind doing this is to determine the precise or exact line of the road. Second, it is done to calculate how much earth will require to be excavated and moved and what quantities of surfacing material will be needed. Third, it is done to find out the amount of surfacing materials required to refill the surface. Finally, it is done to see the quality of the soils so that it has properties of high load bearing capacity. Soil should be permeable for good drainage and easily compacted for good bearing capacity. Otherwise, the road surface will not be durable.