Geotechnical engineering

Geotechnical engineering is a practice that relates to the engineering behaviour of the earth and its materials. As a branch of civil engineering it is of great importance to construction activities taking place on the surface or within the ground, as well as to mining, coastal, drilling and other disciplines.

Despite having considerable overlap, geotechnical engineering differs from engineering geology in that it is a speciality of engineering, whereas the latter is a speciality of geology.

Geotechnical engineers are responsible for evaluating subsurface and soil conditions and materials, using the principles of soil and rock mechanics. They are commonly appointed as consultants on construction projects. Engineers also examine environmental issues such as flood plains and water tables. By doing so, they are able to determine whether a particular site is suitable for a proposed project, and can inform the engineering design process with regard to how ground conditions can be made safe and effective for construction.

From geotechnical surveys, engineers will be able to evaluate the stability of the ground, including any slopes and soil deposits, assess any risks and/or contamination, and help to determine the types of foundations and earthworks that will be required. The potential for hazards such as landslides, earthquakes and other seismic activity can also be assessed.

Geotechnical engineers can be involved in ‘ground improvement’, in which soil is treated through a variety of different techniques to improve strength, stiffness, and/or permeability.

Geotechnical engineering is also important in coastal and ocean engineering, in relation to building wharves, jetties, marinas and coastal defences, as well as foundation and anchor systems for offshore structures such as oil rig platforms. Engineers may also work on embankments, tunnels, channels, reservoirs, irrigation systems, and so on.