ENGINEERING AND LAND SURVEYS
This chapter discusses important factors of engineering surveying and is presented from the viewpoint of the party chief. Included in the discussion are de-sign- data surveys, such as route surveys; and construction surveys that include stakeout and as-built surveys.
Also discussed in this chapter is land surveyingwhich is a special type of surveying performed for the purpose of establishing or reestablishing land boundaries, preparing legal property descriptions, and subdividing tracts of land. Although a complete coverage of land surveying is beyond the scope of this TRAMAN, you will be acquainted with the procedures and some of the legal aspects involved.
In the EA3 TRAMAN, you learned that engi-neering surveys are subdivided intodesign-data sur-veys and construction surveys. A design-data survey is an orderly process of obtaining data that is needed for the planning and design of an engineering project. The activities involved in design-data surveying vary according to the type and complexity of the engineer-ing or construction project; for example, the activities might include simply obtaining topographic data for a proposed building site, or they may include extensive route surveying and soils investigation for a highway. Construction surveying is divided into (1) the layout, or stakeout, survey and (2) the as-built survey. The layout, or stakeout, survey consists of locating and marking (staking) horizontal and vertical control points to guide construction crews, and giving line and grade as needed to establish additional control points and to reestablish disturbed stakes. The as-built survey includes making measurements to verify the locations and dimensions of completed elements of a new structure and to determine the amount of work accomplished up to a given date.
Letís begin the subject of engineering surveyswith a discussion of route surveying.
A route survey, as the name implies, is a surveythat deals with the route or course that a highway, road, or utility line will follow. While the end product of a route survey for a highway certainly differs from that for a utility line, it may, nevertheless, be said that the purposes of any route survey are to
1. select one or more tentative general routes forthe roadway or utility,
2. gather enough information about the generalroute to make it possible for designers to select the final location of the route, and
3. mark this final location.
Consistent with these purposes, a route survey is usually broken down into reconnaissance, preliminary, and final-location survey phases that satisfy, respectively, each of the purposes given above. Sometimes, however, circumstances may preclude the requirement to perform all three phases; for example, if a new road or utility line is to be constructed on a military installation having well-marked vertical and horizontal control networks and up-to-date topographic maps and utility maps, then perhaps the reconnaissance and preliminary survey phases would not be required. Chapter 14 of the EA3 TRAMAN discusses each phase of route surveying asapplied to roads and highways. That discussion is presented in sufficient enough depth to preclude the need to further discuss highway route surveying in this TRAMAN. You should, however, review that discussion and read other publications dealing with the subject of route surveying.
Aside from roads and highways, other uses of route surveys are for aboveground utility lines-most commonly power and communication linesóand for underground utilities, such as power, communication, sewer, water, gas, and fuel lines. The character of the route survey for a utility will vary, of course, with different circumstances; for example, a sanitary sewer, water distribution line, or an electrical distribution line in an urban area will generally follow the streets on which the buildings it serves are located. Also, since these areas will, in all likelihood, have other existing utilities, there should be existing utilities maps that can be used in the design of the newutility line. Consequently, in cases such as this, reconnaissance and preliminary surveys are seldom necessary. On the other hand, a power transmission line or other utility running through open country on a large military installation may require reconnaissance and preliminary surveys in addition to the final-location survey.
For discussion purposes, letís consider routesurveys for overhead electrical lines.