Construction Surveying is the practice of working hands on with construction crews and guiding them through the construction phase of a project.
Contractual documents, consulting engineer, or local bylaw may all have specifications that must be adhered to or the project may be rejected. To meet these requirements of the project various instruments may be employed for Construction Surveying including Total Stations, RTK GPS, Static GPS, Digital levels and terrestrial scanners. Tolerances vary greatly from 2mm on a bridge or building to 30mm on a road subgrade. It is the Construction Surveyors job to asses the task at hand and use the instruments and procedures that will meet the required accuracies with the highest efficiency.
Construction Surveyors analyze, interpret, and implement engineering and architecture drawings into a form that construction crews can use in the field. Construction Surveyors are responsible for the layout of streets, highways, bridges, superstructures, buildings, manholes, pipe mainline, hydrants, catch basins, streetlights, and shallow utilities such as gas and electrical. We have even been hired to layout placement of trees and grapes in orchards and vineyards.
Field layout typically includes leaving a nail or marker at the centre of a feature such as manhole or bridge abutment corner. The stake will also provide a geodetic elevation and a grade to set the feature to the proper elevations. Construction Surveyors also typically offset the construction feature so that construction crews can accurately place the feature once the centre is removed by excavation.
It is also the Construction Surveyors job to protect and if necessary relocate horizontal and vertical control points throughout a construction project. Most projects are designed based on a preliminary topographic survey and the same control must be used referenced throughout the duration of the project.
Once construction is complete an as built survey is typically required and the Engineer will produce “As Constructed Drawings” to verify the project has been built to meet the requirements and specification’s.