Surveying is the science of determining the relative location of objects or points on the earth’s surface. These points can be anything physical, such as highways, culverts, ditches, storm drains, property corners, etc. Distance and direction determine the horizontal location of these points. Vertical location is determined by the difference in elevation measured from a reference location known as the benchmark.
About the Book
This book presents the basic principles and practices of surveying in highway construction and maintenance work. It explains how to measure horizontal distances and vertical elevations, how to measures taking and grades, and covers many examples and exercises.
Accuracy is very important in surveying work. Certain points must be measured to the nearest 0.01 foot. Others may have to be measured to the nearest foot horizontally and to the nearest 0.1 foot vertically. Accuracy may also be expressed as a ratio, such as 1/100 (one-hundredth). This means that a measurement must be accurate to within one footat100 feet, or with in10 feet at a distance of,say,1,000 feet.
Before selecting personnel and choosing surveying equipment, it is important to determine the accuracy required for the task. For example, cut and fill slopes and gutters do not require as much accuracy as drainage inlet grades or finished pavement grades. Surveying is never as accurate as it can be. There is always room for error in surveying, so be sure to check constantly. It is better to take the time to get it right than to run up the time and expense to correct mistakes.