Page 95 - Moving the Earth_ The Workbook of Excavation

SURVEYS AND MEASUREMENTS

SURVEYS AND MEASUREMENTS 2.45

FIGURE 2.41 Measuring a bank.

The same procedure is followed each time the bank is measured. On all calculations after the
first it is usual to determine both the amount removed since the previous measurement, and the
total amount removed since the job began.

Pile. An experienced estimator can often judge the volume of a pile quite accurately by inspec-
tion, without measurement. However, appearances are often deceptive, and most people are safer
if they make at least approximate measurements as a check.
Piles can often be conveniently measured by calculating the volume of regular masses of sim-
ilar outline, and making plus or minus adjustments for differences.
A pile of clean, dry sand may have a conical shape, or be a ridge with a triangular cross section,
ending in half cones. Measurements should be taken to determine base size and height. See Fig. 2.42.
The area of the circular base of a cone is found approximately from the circumference by the
formula
circumference 2 (2 r) 2
Area
12.6 12.6
and from one-half the diameter by

Area 3.14 radius 2

The volume of a cone is the height times one-third the base area.
The long part of the pile is figured by the formula
height width length
Volume
2
A long pile will have the volume of the center section, plus the volume of one cone, as each of
the ends is a half cone.
When the pile shape is flattened, different, or irregular, profiles and cross sections are taken in
the same manner described for banks.