Construction survey provides horizontal and vertical layout for Project's key components. They involve with horizontal and vertical control and the placement of stakes to establish a framework for the construction site.
From this control, lines and grades are established by means of stakes and strings. CPP/IBCI applies these stakes and strings to place supplemental stakes that may be necessary to guide the construction activities.
In summary, construction surveying is the process of drawing the design plans on the actual construction site at the designated location and at a scale of 1:1.
Construction surveying techniques are also used for verifying the location and quantities of completed work (as-built).
Traditionally, "station/offset" method is used for establishing construction control. The introduction of computers, total stations and GPS in surveying have revolutionized the way construction surveys are done now. Construction surveys are now based on the three dimensional (X,Y,Z) coordinate system with which the design was made. From the three dimensional coordinates, angles and distances are computed to facilitate radial stakeout. Radial stakeout data can be downloaded into many total stations or electronic data collectors. This data guides the surveyor to the location of the points to be staked out. Three dimensional coordinates of the construction plan can also be downloaded into a GPS receiver and used in a real time kinematics mode to stake out the site.