Earthwork Quantities by Random Sampling

Statistical methods are applied to determine earthwork quantities. First, cut and fill areas are delineated and planimetered. Then, a table of random numbers is used to locate sample items of depths of earthwork. The volume of earthwork is the product of the planimetered area and the weighted average of the sampled depths. The precision (error) of the answer is expressed as a function of confidence limit; average depth; contour interval; and number of sample items. This method is rapid and accurate and yields the most meaningful results when compared with any other method in use today for computing earthwork quantities. The distribution of cut and fill areas can also be determined from the sample items used to find the depth of earthwork. This introduces a second kind of error. Errors are quantified.