Page 210 - Urban Construction Project Management

Layouts and Surveying

7 (We are only off by 1 foot. Big deal!)

SURVEYING

Building surveyors have been around before the great pyramids of Egypt were built.
For the great pyramid at Giza, the surveyors understood how to calculate angles (52° on
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all sides), level the base within / in. and measure lengths (750 feet on all four sides
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with an error of only 8 in.). This is quite an accomplishment considering the fact that
they had no sophisticated surveying equipment or the use of GPS. There are no indica-
tions that corrections were made for heat, tension of the measuring rope, or for keeping
the measuring rope from sagging. The need for surveyors became more prominent in
history as land was divided by the various monarchs of the time. The need to measure
property areas and boundaries became the requirement for not only indicating land
ownership but for tax purposes as well. During the Middle Ages, the surveyor had to
lay out fortifications, castles, religious buildings, municipal buildings, and other struc-
tures. This all gave rise to the modern building urban surveyor who is responsible for
the layout of the building site, location of the footings, determination of the floor ele-
vations, and the complete alignment of the building being constructed. Due to limited
access to sites in the urban environment, the surveyor has to deal with vibration from
traffic and mass transit, the set up of equipment with pedestrian traffic (potential for
knocking over the equipment), and trying to obtain line of sight with numerous imped-
iments in the way (buildings, trucks, cars, cranes, construction equipment, etc.). See
Exhibit 7-1 for the surveyor setting up within an urban environment. The surveyor uses
several bench marks for setting up the instrument and for determining elevations.
Exhibits 7-2, 7-3, and 7-4 show markers in the sidewalk that are used by the surveyor.
However, the surveyor prevails, and the work is accomplished with the utmost accuracy.
See Exhibit 7-5 for the site survey flowchart.

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