Why a Civil Engineer needs to study Geo-technical Engineering?

Almost all Civil Engineering structures are in contact with soil mass or rock. Soil can either be in undisturbed natural state or artificially placed , such as, under foundation of the structures, the soil may be in-situ or artificially placed whereas behind retaining walls soil is always artificially placed. Similarly in the construction of structures such as dams, levees, embankments for roads and railways, airfields etc; soil is artificially placed. Irrespective of the fact, whether soil is used as a supporting material e.g. under foundations or as construction material e.g. in earthen structures, there is an interaction between the soil and the adjacent soil; and as a result of this interaction the stresses developed in both (soil and the structure) causing some changes in shape and size of the structure as well as the adjacent soil mass.

To design stable an durable structures, an engineer must therefore, be able to visualize these changes and forecast their behaviour at any time i.e. before, after and during the construction of a structure. Hence, besides analyzing the stress and strain produced by structural loads such as self loads, external loads etc; it is necessary to determine or estimate the following:

1. The character and the value of stress in the structure and the adjacent soil mass due to their interaction.
2. The character and the value of changes in shape and size of the structure and the adjacent soil mass.

Soil being the natural product is a very complex engineering material and to understand its behaviour, study of Geo-technical Engineering is essential.  More specifically a good knowledge is required for:

• Design of foundations
• Slope stability
• Design of earthen structures (earthen dams, retaining walls, sheet piles etc)
• Design of roads and railway embankments and airfields