Pile Driver Usefulness Through History July 23, 2010

In today's massive commercial construction projects,pile drivers and proper pile driving techniques are critical to the establishment of a sound and reliable foundation. Although modern technology has produced fascinatingly efficient machines to insert a variety of pile types into the earth, pile driving techniques and methods have been around for thousands of years.

Likely since the dawn of time man has desired a way to make life easier through the construction of objects designed to overcome natural barriers. Builders of modern marvels such as the Burj Dubai (now the tallest structure in the world) have had the fortune of leveraging the experience and intelligence of architects, designers, and contractors that came before them.

A construction feat that often bewilders individuals that do not work in the construction field is the ability of construction crews to establish foundations for bridges and other structures in water. One of the most fascinating examples of man's ingenuity is the formation of a cofferdam for foundation development in water.

A cofferdam is essentially a damn that holds back water while construction crews develop the foundation of the structure to be built; bridge foundations are an example. Cofferdams are not new to construction; however, the machines by which they are constructed have changed over the centuries. One of the earliest uses of cofferdams dates back to around 103 A.D.
In the Iron Gates Museum in the city of Turnu Severin, Romania is a model of a bridge built during the height of the Roman Empire in honor of Trajan, the thirteenth Roman Emperor. Trajan ordered that a bridge be built across the Danube River (which today would connect Romania and Serbia). The bridge was constructed of wood and the structure's foundation was created out of huge stone piers, according to historians.

To erect the stone piers the Romans utilized a cofferdam made of oak or alder pilings. The piles, which were sharpened on the end, were driven into the riverbed by a rudimentary pile driver. The driving force for the pile driver was a large stone that was hoisted into the air through the use of a pulley and manual labor and then released. Piles were driven side by side into the river in a horseshoe shaped pattern from the shore. Historians state that the Romans often erected double-walled cofferdams for stronger support against the water on the outside.

Today's cofferdams are established much more easily. In a typical installation a vibratory pile driver/extractor can insert specially designed sheet piles into the earth under the water. Vibratory pile drivers utilize eccentric weights to vibrate the sheet pile as it is driven into the ground. The vibration of the pile allows it to move easily into the riverbed, seabed, or lakebed. Some of these piles are designed to interlock to create a water barrier; others require welding operations to secure them fully. As with the Roman methodology, once the perimeter is established the water inside of the cofferdam is then removed to create a dry project site.
 

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