Method of providing definite cross slope by varying thickness of foundations under roads

This method was proposed by Telford, a Scottish civil engineer, in the late 18th century. The method involves varying the thickness of the foundation of a road in order to provide a definite cross slope, which helps to ensure efficient drainage of rainwater from the surface of the road.

The following are the steps involved in this method:

1. Surveying and designing the road: The first step is to survey the site and design the road. The cross slope is determined based on the expected volume of rainwater that needs to be drained from the road.

2. Excavation: Once the road is designed, the excavation is done to the required depth to lay the foundation.

3. Laying the foundation: The foundation is laid in layers of varying thickness, with the thicker layers being placed on the lower side of the road. This creates a slope in the foundation, which is then reflected in the surface of the road.

4. Laying the pavement: After the foundation is laid, the pavement is laid on top of it. The pavement is designed to follow the slope of the foundation, which ensures that the surface of the road is level and provides efficient drainage.

Advantages of this method:

- Provides a definite cross slope, which ensures efficient drainage of rainwater from the surface of the road.
- Can be used in areas with varying terrain and soil conditions.
- Provides a stable foundation for the road, which helps to prevent damage and prolongs the lifespan of the road.

Disadvantages of this method:

- Can be time-consuming and labor-intensive.
- Requires skilled workers to ensure that the foundation is laid correctly.
- May not be suitable for areas with high traffic volume, as the slope can cause discomfort for drivers.