Definition of Geoengineering and Geotechnical engineering is described as follows.
Geotechnical engineering is the branch of engineering concerned with the engineering behavior of earth materials. Geotechnical engineering uses principles of soil mechanics and rock mechanics to investigate subsurface conditions and materials; determine the relevant physical/mechanical and chemical properties of these materials; evaluate stability of natural slopes and man-made soil deposits; assess risks posed by site conditions; design earthworks and structure foundations; and monitor site conditions, earthwork and foundation construction.
A typical geotechnical engineering project begins with a review of project needs to define the required material properties. Then follows a site investigation of soil, rock, fault distribution and bedrock properties on and below an area of interest to determine their engineering properties including how they will interact with, on or in a proposed construction. Site investigations are needed to gain an understanding of the area in or on which the engineering will take place. Investigations can include the assessment of the risk to humans, property and the environment from natural hazards such as earthquakes, landslides, sinkholes, soil liquefaction, debris flows and rockfalls.
Geoengineering covers a wide range of engineering disciplines related to geo-materials, such as foundation engineering, slope engineering, tunnelling, rock engineering, engineering geology and geo-environmental engineering.
The modern concept of geoengineering describes deliberately manipulating the Earth’s climate to counteract the effects of global warming from greenhouse gas emissions. Other uses of the word sometimes occur.
The National Academy of Sciences defined geoengineering as “options that would involve large-scale engineering of our environment in order to combat or counteract the effects of changes in atmospheric chemistry.”