A construction surveyor works in many civil construction projects as well as other engineering projects, such as mechanical machines. Let us look at what a construction surveyor is expected to offer and what he/she should do to get the desired results.
Data furnished to civil engineer for design purposes
Sometimes known as engineering surveyors or topographical surveyors, construction surveyors normally begin work well before site establishment. A topographic survey usually precedes any form of work on a site. Before a civil engineer can come up with a design, he or she requires certain information about the topography of the area of interest.
The single most important product of a topo survey is the contour map. Engineers need contour maps for them to design how the finished structure and ground should look like. Such finished structures such as drainage systems and structure relationship with other utilities. Therefore a topographic survey forms part of the initial data requirements for design. So an engineering surveyor goes out to survey the land first, for two primary reasons. The first one is to map the positions of existing features, such as trees, rivers, streams and any existing man made feature like roads and buildings. The second one is to produce contours to show the existing ground undulations for design purposes
Construction surveyor services on site
Once a civil engineer has completed his or her designs and drawings, construction surveyors can proceed with setting out surveys. Setting out survey refers to the measurements taken by a surveyor to transfer drawing positions to the ground with precision. Let us say, for instance, a drawing suggests that the finished ground levels should slope at 1% gradient, from a certain position to another. The engineering surveyor should survey and mark out positions on the ground that should guide contractors to achieve that.
Setting out surveys are done for ground preparations during earthworks, and during erection of structures to guide contractors with levels and positions of structure. For a steel structure, setting out might involve marking out the positions of holding down bolts, for which steel columns will be fixed. A surveyor on site will typically set out positions of concrete columns and bases, from the position of shuttering to the actual concrete position. Most engineering drawings come with grid lines. Surveyors on site can mark out grid lines to give the contractors a point of reference. All that is part of setting out.
Construction Surveyor : Other Services on site
Site surveyors also provide alignment survey services. These surveys can be either for structural steel, mechanical or civil structures. A good example is the alignment of crane rails on site. It is crucial for erection teams to work closely with engineering surveyors in order to get positional guidance. Surveys also enable to achieve high accuracy and avoid re works due to errors in positioning. Absence of surveyors on site results in unwanted demolitions of portions of structures due to misalignment. Clash of positions of structures is also common or even malfunction of design features. It is more costly to run a construction site without surveyors than to employ surveyors, especially for large projects.
As built surveys
As built surveys are done as the final record of measurement of structures, as a final record keeping. It is important to record and maintain the positions of structures and have a comparison with the design positions. Sometimes it happens that, while erection teams are busy with their work, there can be unwanted movement. Examples are the movement of shuttering during concreting. Such a movement can alter the position of a concrete structure as it dries. An engineering surveyor should record the final positions for analysis. Sometimes it may be necessary to break a portion and have it redone if the engineers sees it fit.
Distinction between professional land surveyor and engineering surveyor
For the general populace, an engineering surveyor can be loosely referred to as a land surveyor. However, this may be misleading in the scope and extent of duties.
In South Africa, a professional land surveyor is a surveyor who is so registered with the South African Geomatics Council (SAGC) formally known as PLATO. Land surveyors in South Africa have a license to perform demarcation surveys and sign off for lodging at the Surveyor General’s Office. These surveys, known as cadastral surveys, form a legal basis for title of properties. Land surveyors therefore, can perform any survey be it engineering or cadastral surveys. On the other hand, however, a construction surveyor may not perform cadastral surveys without supervision by a registered land surveyor.