1.3. Objectives of engineering geodesy

The main tasks of engineering geodesy in the survey, design, construction and operation of various structures are:

• obtaining geodetic data (geodetic measurements) in the development of projects for the construction of structures (engineering and geodetic surveys);
• determination on the ground of the main axes and boundaries of buildings in accordance with the construction project (marking works);
• ensuring in the process of construction geometric shapes and sizes of building elements in accordance with its design, the geometric conditions of installation and commissioning of process equipment;
• determination of deviations of the geometric shape and size of the erected structure from the design (executive surveys);
• the study of deformations (displacements) of the earth's surface under the structure, the structure itself or its parts under the influence of natural factors and as a result of human actions.

Engineering and geodetic surveys are carried out to create maps, plans, digital terrain models, which, based on the results of ground and aerospace surveys, depict what is on the ground. The created topographic and geodetic basis is used for the design of the structure - the development of its project.

During construction, using geodetic measurements, they perform the inverse geometric transformation — they transfer the construction project to the terrain, i.e. determine on the ground the place where the building should be located on the project. This process is called geodetic maintenance of construction.

For different types of structures apply different requirements for the accuracy of geodetic support. The accuracy of the work to be carried out when installing the building structures on the sites provided for by the project should be within 5 ... 10 mm, parts of the factory conveyor - 1 ... 2 mm, equipment of physical laboratories for nuclear particle accelerators - 0.2 ... 0.5 mm

Upon completion of the construction of the facility and during its operation, the task of periodic monitoring of the state of the erected structure arises, which is called monitoring of the state of the structure. This monitoring is carried out by specialized survey and geodesic organizations, both terrestrial and aerospace methods.

By type of work performed, engineering surveying is divided into:

• ground;
• underground (surveying);
• air;
• underwater.