Page 19 - Urban Construction Project Management

xviii Introduction
HISTORY OF CONSTRUCTION

As long as men and women have been on earth, they have had an ongoing quest to
construct buildings of various types to be able to provide housing, shelter, meeting
places, houses of prayer, and workplaces, as well as areas that meet their special
needs and monuments to their empires and cultures. People first found shelter by liv-
ing in caves. However, this became a problem with the invention of fire and animals
wanting to share their abode. As humanity started to explore other venues, the need
for temporary shelters became apparent. At that time, only basic raw materials and
methods were available, so the shelter was built with tree limbs and leaves. The
Great Pyramid at Giza, which was built by the Egyptians over 4500 years ago, is one
of the great wonders of the world. With the use of large stone granite and limestone
blocks (some weighing over 2.5 tons), the Egyptians created a lasting monument to
the Pharaoh. This was accomplished without the use of the wheel, steel tools, or
cranes. The Pyramid at Giza was constructed using very simple surveying tools,
bronze tools, and a huge amount of free labor. Most of the labor was made available
when the Nile overflowed, in that the workers could no longer cultivate the land for
agriculture. When the floods receded and during harvest time these workers went
back to tilling the fertile land. Approximately 5000 people were full-time workers
and were used to cut the granite and limestone slabs. This number also included a
primitive construction management team. It is estimated that approximately another
21,000 were part-time workers. Construction has always been an industry that is
very labor intensive, and uses raw materials that have been readily available.
However, the Egyptians had to go to Aswan (500 miles away) to obtain the granite
for the structurally critical elements of the pyramid. They used boats and human and
animal power to slide large blocks of stone across the desert sand and built slopes of
sand to access elevations and grades. The pyramids were sophisticated structures
with precise axes for their layout (a slope of 51°). They were structurally intricate
and the workers utilized a lot of innovative tools and techniques to accomplish the
construction.

The Egyptians understood geometry, astronomy, and the load-bearing capacity of
materials and the management of people. Then from Roman times to the Dark Ages,
humans learned how to more effectively build structures. They were capable of using
pulleys, cranes, and the wheel to construct massive government buildings and fabu-
lous religious buildings (Notre Dome in Paris as one example). From there humans
discovered the ability to smelt cast iron, allowing buildings to be built to a height of
several stories. The Bessemer steel process allowed for the beginning of steel struc-
tures reaching new heights and the beginning of the modern skyscraper. A skyscraper
would not have been possible without the invention of the elevator and the safety
brake by Mr. Otis to carry people above six stories. Electrical distribution and light-
ing systems developed by Thomas Edison gave people the ability to work in high-rise
buildings during all hours and seasons. The ability to supply water via reservoirs such
as the Croton Reservoir in upstate New York, water from rivers and lakes, such as the
Great Lakes supplying cities like Chicago with water, along with pumps to deliver