Construction is All Around Us
No matter where in the civilized world you go, construction crews are bound to follow-or else they have already been there. Buildings, highways, bridges, pipe or high-tension lines, plus countless other manmade structures, all require construction crews to create or modify them. And where you find construction, you will invariably find one or more construction surveyors.

Starting Off on the Right Foot
Before any construction job can proceed, the project area must be surveyed. The drawings created by the engineering team must be oriented to the actual lie of the land. Measurements of the building site are taken using surveying equipment, which are then compared to the set of master blueprints. These initial measurements will serve as the basis for all events that take place throughout the construction process.

The Total Station-The Surveyor's Top Tool
Prior to the electronic age, surveyors used something called a transit to help mark locations and perform other surveying-type tasks, such as defining angles. The total station is the modern update of that vital tool, and it is the prime piece of equipment in any construction surveyor's bag of tricks. Sitting on a tripod, the total station uses trigonometry, triangulation, and coordinates (x-y-z in a three-dimensional plane) to measure angles and distances in the field. Points are marked and noted in the total station's software, and all data can be downloaded to any number of computing-type devices in order to create a map, modify an existing map, or simply confirm that map data are correct. These days, GPS data are also incorporated into the total station's computing ability. In outdoor locations where sky visibility is adequate-urban canyons or heavy tree canopy conditions can be problematic-it is not unusual for a construction surveyor to achieve sub-centimeter accuracy.

Highway Construction Surveying
The placement and construction of highways is one area where the involvement of a construction surveyor is especially valuable. First, the existing terrain is surveyed. Areas are noted where dirt must be excavated, especially to what level and grade. Once the material is moved, the surveyor will double-check that everything matches the plans. One goal is to reduce the distance excavated material travels, so engineers take the surveyor's computations and create something called a "mass diagram" to figure out optimal relocation sites. In other words, they will take dirt from Spot A that requires reduction and move it to Spot B that requires build-up. In the old days, wooden stakes were driven into the ground to mark road edges in the highway alignment stage, but the accuracy and widespread usage of GPS has eliminated this laborious process.

Building Construction Surveying
A construction surveyor controls the location of everything from foundation lines to footings to ancillary items such as sidewalks and driveways. Using a total station and observed GPS data in a manner similar to highway construction, every spot and corner is noted in the field and then compared to the master plan. One specialized job for the construction engineer is to ascertain the proper placement of anchor bolts on structural steel and pre-cast concrete. Because of the nature of the item-these bolts, after all, are responsible for holding the building components together-the exact placement of each bolt is critical to structural integrity. Since there is such a wide variety of design in buildings, anchor bolts can be placed anywhere within or without the building's footprint. They may not fall in a straight line, so a construction surveyor must be ever vigilant to follow exactly the architectural and engineering plans when marking anchor bolt locations on individual structural components.