The history and design aspects
of the Eiffel Tower are interesting for engineers even today. Wrought iron was
used for the construction of Eiffel Tower with the employment of scaffolds.
Mathematical formulas were deliberated for numerous calculations for wind
forces and load conditions.
The Eiffel Tower was
constructed in Paris for the World Fair 1889 celebrating the centennial of the
French Revolution. The Prince of Wales inaugurated the tower. The number of
proposals submitted for the design of Eiffel Tower exceeded 700, and Alexandre
Gustave Eiffel was selected for this important task. The Eiffel Tower is an
iron lattice of the 19th century that is considered to be a universal symbol.
It is amongst the Seven Wonders of the World, and one of the most familiar
structures. The Eiffel Tower was initially intended to be built in Barcelona,
but the location was changed since it was considered to be an expensive
proposal. Three hundred workers were employed for this gigantic task that was
completed in 2 years and 2 months. The construction involved extensive risks
since the safety technology was not yet developed adequately in that era. Risks
were severe since neither the modern skyscrapers were available nor the other
modern safety equipment had yet been developed. However, due to the care and
precautions adopted in the construction, only one labor died
during the process.
Soil analysis was conducted to
accurately establish the suitability of soil for the tower with a weight of
approximately 10,000 tonnes. It was discovered that though some of the soil was
firm and suitable for enduring the tower load, a lot was soft soil that could
not resist the heavy load. Additionally, this area was vulnerable to flooding.
Using his engineering genius, Eiffel designed two separate systems for the
tower foundations, namely the dry foundation and the compressed air system. The
foundations near the riverside were dug deeper than those located on the dry
side. These foundations were injected with compressed air and metal components
normally used for the underwater construction. After completion of the digging,
quick drying cement was poured for the provision of the base for the foundation
piers. Massive limestone blocks were placed over the cement and sealed by layers
of cut stone.
The Eiffel Tower was built
utilizing the most modern engineering technology available in the nineteenth
century. Advanced information about the performance of metal trusses and metal
arcs under load, including the calculations related to the wind forces, were
incorporated in the design. The tower was made of wrought iron and was intended
to withstand high wind pressures near the top and throughout the structure.
Many similar structures constructed during that era had much less capability to
resist such high wind pressures, and a few of the bridges failed due to
inaccurate calculations. The design of the Eiffel Tower was not based on a
single mathematical formula. Instead, graphical results were used to determine
the necessary structural strength, and empirical evidence was utilized to
establish the effects of wind on this gigantic structure.