between stations 1 + 00 and 3 + 50 would be dumped
into the adjacent fill space between stations 3 + 50 and
6 + 00. The fill space between stations 6 + 00 and 8 +
00 would be filled with borrow; that is, material taken
from a nearby borrow pit. The fill space between
stations 8 + 00 and 10 + 50 would be filled with the
cut between 10 + 50 and 13 + 00, and the space
between stations 16 + 50 and 19 + 00 would be filled
with the cut lying between stations 14 + 00 and 16 +
50. You will notice that the haul limit on the last
section of the mass diagram (between stations 14 + 00
and 19 + 00) is almost on the line of zero yardage. This
haul-limit distance also is called the balance line,
because the volume of cut is equal to the volume of
fill. If, for example, the balance line on the last section
of the mass diagram in figure 10-10 is only about 400
feet, then instead of wasting the cut between stations
13 + 00 and 14 + 00, you would use that to fill the
hollow between stations 19 + 00 and 20 + 00. Surplus
cut remaining would naturally be wasted after
allowing for shrinkage in the filled spaces.
CONSTRUCTION SURVEYS
In this section we will discuss construction
surveying, as it pertains to the stakeout of various
types of construction, such as bridges and culverts,
sewer lines, airfield runways, and waterfront
structures. For a refresher of stakeout surveys for other
types of construction, such as buildings and
pavements, you should review chapter 14 of the EA3
TRAMAN.
As mentioned early in this chapter, as-built
surveying is performed for two purposes: (1) to
determine the horizontal and vertical location of
points as they are actually constructed in the field and
(2) to determine the amount of work accomplished up
to a given date. Towards the first of those purposes,
little can be said that is not adequately covered in the
EA3 TRAMAN; therefore, the below discussion of
as-built surveying is geared towards the second
purpose.
First, however, let’s consider an aspect of both
as-built and stakeout surveying that is of particular
significance to the party chief; that is, the party chief
must maintain close liaison with the other crews
working on the project. Survey parties work
independently on many types of surveys, such as
establishing horizontal and vertical control, running
preliminary lines, shooting topo, and gathering
engineering data. But in stakeout, the survey party is
an integral part of the construction team. Timing and
scheduling are important. When line and grade stakes
are not set at the right place and at the right time, the
work of entire construction crews are delayed. The
party chief must also be constantly aware of the need
for replacing stakes that have been knocked out by
accident or design. Frequently, changes in grade and
alignment will be authorized in the field to best meet
the conditions encountered. These field-change orders
will, in many cases, require immediate computations
in the field and revisions to the stakeout. It is best to
obtain as-built data as soon as a section of the work is
complete. This is particularly true if field changes
have been made, since the press of further construction
may prevent a timely return to the job to obtain the
as-built data. When this data is not obtained, users of
the plans may be seriously misled in supposing that
the construction conformed to the original drawings.
As-Built Surveys for Monitoring
Construction Progress
In the Seabees, the percentage of completion for
construction projects is based on a work in place
(WIP) concept. To explain this, let’s consider a simple
example in which Charlie company is required to paint
out three rooms totaling 1,100 square feet of wall and
ceiling surface. When half of the total square footage
is completed, the work in place is 550 square feet and
the painting work is 50 percent complete. When all
surfaces have been painted, then the work is 100
percent complete.
Now let’s assume that a construction battalion is
tasked with the construction of 15 miles of
bituminous-paved road. As you know from your study
of chapter 3 of this TRAMAN, the construction of this
road will include construction activities, such as
clearing, excavation for base and subbase courses,
installation of drainage structures, placement of base
and subbase courses, prime coating, and laying the
bituminous-surface course. Each of those activities
represents a certain percentage of the total project.
Let’s assume that the construction activity for clearing
is estimated to be 5 percent of the total project and that
this activity involves the removal of 528,000 square
yards of brush and overburden. When all of the
clearing is completed and no other work has been
accomplished, then the project is 5 percent complete;
however, if only 130,000 square yards has been
removed and no other work has been accomplished,
then about 25 percent of the clearing activity has been
completed and the project is .05 x .25 = 1 percent
complete.
10-14
