EPA Infrastructure Pvt. Ltd.EPA Infrastructure Pvt. Ltd.

Sub-Grade Preperation

B-267, North Ex MallSector-9, Rohini,

Delhi-110085

What is Sub-Grade?

In transport engineering, subgrade is the native material underneath a constructed road, pavement or railway track. It is also called formation level.

The term can also refer to imported material that has been used to build an embankment.

Preperation of Sub-grade

Subgrades are commonly compacted before the construction of a road, pavement or railway track, and are sometimes stabilized by the addition of asphalt, lime, portland cement or other modifiers. The subgrade is the foundation of the pavement structure, on which the subbase is laid.

Preparation of the subgrade for construction usually involves digging, in order to remove surface vegetation, topsoil and other unwanted material, and to create space for the upper layer of the pavement. This process is known as "subgrade formation" or "reduction to level".

Subgrade shall be free from all foreign debries and rock outcrops

Geotextile being laid on the uncompacted layer of soil

Compacting the soil surface after geotextile layer

Surface elevation before paving

Finally prepared subgrade