A Surveying Abstract
Site surveys are conducted for a number of reasons. These include the need to produce a map of an area, to determine the exact dimensions of an area, and to establish the parameters of a building zone. The process of surveying an unimproved site is one of the first things to be done prior to construction, whether one is planning an office building, a stretch of retail stores, or a housing development. Surveyors are called upon to capture an as-is picture of the site in question, noting natural features such as hills and slopes, valleys and rifts, and bodies of water. Once land developers have completed an initial site plan that will accommodate the structure(s) to be built, a survey team is again dispatched to mark out areas that require alteration.
Types of Surveys
Several different kinds of surveys are employed when preparing a site for construction. The first is known as the control survey. Specific points are identified within the site and used to calculate the proper positioning of all other required elements. Several known points are logged; these days a GPS sensor is used to note exact positions in longitude, latitude and altitude. Assuming the building site is unobstructed from above-lacking a heavy tree canopy, for example-sufficient GPS data can be collected to pinpoint these locations to within just a few millimeters. Next is the detail survey, which is constructed by radiating lines from and between the control points. Surveyors use instruments to measure angles and distances and, with that data, construct an accurate map of the site in question.
Site Leveling
No matter what sort of building or group of buildings is being constructed, they must rest on a perfectly level site. The prospect of finding a naturally level stretch of ground exactly where you want it is highly unlikely, so some amount of excavation is almost always necessary. Surveyors will plot sight lines, stake out the area that requires leveling, and then perform regular checks as the work progresses. Precision is important, as a building site must be as close to level as possible-a tolerance of one percent or less is preferred. Using computer software especially created for the purpose, surveyors can import data and calculate the volume of material that must be moved from one place to another in order to create a level site.
Foundation Placement
The first step in constructing a building involves finding the proper location for the foundation. In home construction, this generally involves digging a hole for the basement (if one is to be included) or else pouring a slab of concrete upon which the house rests. In commercial construction, especially for a multi-story building, footers are set in place at prearranged distances in order to distribute the weight of the structure evenly. No matter which method is used, a surveyor is needed to ensure that everything is precisely situated. By using the previously pegged controls, all other pertinent points are transferred from the site drawing to the actual ground. As construction continues, the survey team continuously checks to see that the placement has not gone awry.
The Role of the Project Engineer
A project engineer acts as the liaison between the survey crew and the building crew. He or she uses the site survey to keep track of the process as construction continues. In the event there are discrepancies between the original survey and what is taking place on the ground, the project engineer has the responsibility to make it right.
See Also : Buy Cheapest Best Discounts Buy Best Price Buy Best Price Piles and Foundation
