Examples of construction projects that require professional services of engineering surveyors include projects in which buildings, highways, railways, tunnels for transport systems and utility systems, bridges and harbours are constructed.
Engineering Surveying involves
Project planning and design;
Quality control of construction projects to ensure the projects progress according to their designs and given tolerances; and
Monitoring the performance and health conditions of completed structures and facilities.
Deformation and Settlement monitoring/ Levelling In order to keep track of the designers’ assumptions and predictions and to assess the behavior of the structures for safety reasons, Deformation and settlement monitoring are required. A level essentially comprises a telescope rotatable about a vertical axis; it is used to create a horizontal line of sight so that height differences can be determined and stakeouts can be performed. The basic principle of levelling involves determining the height difference between two points. The height difference is calculated from the difference between the two staff readings. Horizontal Movement – Horizontal movement commonly happens in an upstream – downstream direction in target structure. It involves, the movement of an entire structure relative to its abutments or foundation. Vertical Movement – Vertical movement is commonly a result of consolidation of embankment or foundation materials resulting in settlement of the structure. Another cause is heave caused by external pressure. These two movements can be effectively and accurately measured through Deformation and Settlement monitoring.
Topographic Survey A total station consists of a theodolite with a built-in distance meter (distancer), and so it can measure angles and distances at the same time. Today’s electronic total stations all have an opto-electronic distance meter (EDM) and electronic angle scanning. The coded scales of the horizontal and vertical circles are scanned electronically, and then the angles and distances are displayed digitally. The horizontal distance, the height difference and the coordinates are calculated automatically and all measurements and additional information can be recorded. Total stations are used wherever the positions and heights of points, or merely their positions, need to be determined.