Topographical Surveying
Topographical surveys determining the three-dimensional position, of natural and man-made features on or beneath the surface of the Earth. These features may be represented in analogue form as a contoured map, plan or chart, or in digital form such as a Digital Ground Model.
Either or both of the above formats may be used for planning, design and construction of works.
Setting out
In engineering the production of an accurate large-scale plan is usually the first step in the planning and design of a construction project.
Thereafter the project, as designed on the plan, must be set out on the ground in the correct absolute and relative position and to its correct dimensions, using a Total Station or GPS for 2D and 3D setting out, or maybe a Level for vertical positioning only.
Laser scanning
Laser scanning is the process of analysing a real-world environment to collect data on its shape and its appearance. It can be used along with (or as a complete alternative to) conventional survey methods.
It collects a large amount of data over a short period of time. The collected information transforms in the form of point cloud data, which than can be used to construct maps or digital 3D models.
Monitoring
Monitoring surveys are a precise method of surveying where structures or features, such as railway tracks, bridges, retaining walls or embankments, which are thought to be moving or have the possibility of moving are repeatedly checked to determine the amount of movement or deflection, in 3D, on the level of millimetres if required.
Survey Control Networks
Control survey provides a framework of survey points, in two or three dimensions, to specified degrees of accuracy. The areas covered by these points, form the basis for maps.
The methods used for establishing and maintaining control networks are: Traversing, levelling, GNSS position fixing and network adjustment calculations, such as least square estimation.
As-Built Surveys
Most of the surveys are carried out before the actual construction, but as-built surveys are showing the state of a site at a particular point during or after the works, as well as recording any variations from engineering plans provided and verifying contract compliance.
These types of surveys are usually presented in digital format as a CAD drawing or as a list of coded coordinates.
Volumetric Surveys
Volume measurements are essential in many different processes of a construction, such as earthworks, concreting or asphalting, to provide an independent measure on the quantity of materials.
Whilst most volumetric surveys are done by conventional survey methods, larger scale surveys (e.g., opencast mining) are often carried out using terrestrial or aerial laser scanning or photogrammetry.
Surface Regularity Surveys
Surface profiles of industrial concrete floors must be controlled so that departures from theoretically perfectly flat plane are limited to an extent appropriate to the planned use of the floor.
Engineering supervision during concrete pouring can minimise surface irregularities, whilst surface regularity surveys are verifying compliance with the relevant floor classification standards.
