Geotechnical Engineering is a scientific approach to examining the subsurface. Established as a branch of civil engineering, Geotechnical engineering is concerned with the behavior of earth metals. It utilizes principles of soil and rock mechanics to investigate existing subsurface conditions and materials. Areas of interest include risks posed by site conditions, structure foundations and designing earthworks.
Said to have begun in 1925 by one Karl Terzaghi, geotechnical applies the principles of soil mechanics to analyze and design earthworks and buildings. So, how do geotechnical projects go about?
Geotechnical projects may involve either a surface exploration or a subsurface exploration, additionally, it may involve both.
A typical project begins with a geotechnical investigation of soil (considered a 3 phase material of rock, mineral and air) and bedrock in an area of interest to determine their engineering properties and may include an assessment of the risks to humans, property and the environment. Environmental hazards may include earthquakes, landslides, sinkholes, soil liquefaction, debris flows and rock falls.
Next, the engineer determines and designs the type of earthworks, foundations, retaining structures and/or pavement sub grades required for the intended man-made structure to be built based on the soil characteristics and/or bedrock at the site.
A structures foundation transmits load from buildings and other structures to the earth, therefore, foundations are designed and constructed for structures of various sizes such as high-rise buildings, bridges, large commercial buildings and small structures where the soil conditions do not allow code based design. Structure size is of course based on the foundation support which is dependent on bearing capacity and ground movement beneath the foundations.
A geotechnical engineer also monitors earthwork and foundation construction to ensure that ‘fills’ are properly placed and compacted and that foundations are constructed as designed. Geotechnical monitoring allows engineers to provide reviewed design criteria if the soil or rock conditions in the field do not match the conditions expected from the investigation.
The fields of geotechnical engineering and engineering geology are closely linked, and traverse in some areas. However, the field of geotechnical engineering is a specialty of engineering, whereas the field of engineering geology is a specialty of geology. Geotechnical engineering is also related to coastal and ocean engineering which can involve the design and construction of wharves, marinas, and jetties.