In this section we will discuss construction surveying, as it pertains to the stakeout of various types of construction, such as bridges and culverts, sewer lines, airfield runways, and waterfront structures. For a refresher of stakeout surveys for other types of construction, such as buildings and pavements, you should review chapter 14 of the EA3 TRAMAN.

As mentioned early in this chapter, as-built surveying is performed for two purposes: (1) to determine the horizontal and vertical location of points as they are actually constructed in the field and (2) to determine the amount of work accomplished up to a given date. Towards the first of those purposes, little can be said that is not adequately covered in the EA3 TRAMAN; therefore, the below discussion of as-built surveying is geared towards the second purpose.

First, however, lets consider an aspect of both as-built and stakeout surveying that is of particular significance to the party chief; that is, the party chief must maintain close liaison with the other crews working on the project. Survey parties work independently on many types of surveys, such as establishing horizontal and vertical control, running preliminary lines, shooting topo, and gathering engineering data. But in stakeout, the survey party is an integral part of the construction team. Timing and scheduling are important. When line and grade stakes are not set at the right place and at the right time, the work of entire construction crews are delayed. The party chief must also be constantly aware of the need for replacing stakes that have been knocked out by accident or design. Frequently, changes in grade and alignment will be authorized in the field to best meet the conditions encountered. These field-change orders will, in many cases, require immediate computations in the field and revisions to the stakeout. It is best to obtain as-built data as soon as a section of the work is complete. This is particularly true if field changes have been made, since the press of further construction may prevent a timely return to the job to obtain the as-built data. When this data is not obtained, users of the plans may be seriously misled in supposing that the construction conformed to the original drawings.

As-Built Surveys for Monitoring Construction Progress

In the Seabees, the percentage of completion for construction projects is based on a work in place (WIP) concept. To explain this, lets consider a simple example in which Charlie company is required to paint out three rooms totaling 1,100 square feet of wall and ceiling surface. When half of the total square footage is completed, the work in place is 550 square feet and the painting work is 50 percent complete. When all surfaces have been painted, then the work is 100 percent complete.

For projects such as this, the EA surveyor is often required to perform as-built surveys to determine the work in place for each of the construction activities. These surveys are usually performed on a periodic basis, such as biweekly or monthly. The results of these surveys are then used to determine the completion percentage of the project.

When doing as-built surveys for the purpose of monitoring and reporting progress, the techniques, or methods, that you use are nothing unique. Simply use the method that is best suited for the job at hand. Also, for this type of as-built surveying, extreme accuracy is usually not required; for example, if you are determining how much of a total road surface has been paved, measurements to the nearest foot are usually sufficient.