The WG was set up because bridges, which are the
most critical (from the
seismic point of view) component of transport
systems, were not covered by existing EAEE
task groups. It is noted that within the European
Union, the motorway network expanded from
39200 km in 1990 to 49200 km in 1999, and the figure
keeps increasing at a fast rate. As an
example, in Greece the most significant expenditure
on road infrastructure is conducted
through the Trans-European Network, which accounted
for €13.6 billion; a large number of
bridges have been constructed in Greece during the
last decade, the majority of which was
along the 680 km Egnatia Motorway that includes 646
bridges. Meanwhile, assessment of
seismic performance of existing bridges, some of
which clearly fail to satisfy the requirements
of modern codes, has been the focus of substantial
research efforts worldwide, particularly
during the last few years. As a result of such
concerns, programmes for retrofitting
seismically deficient bridges have originated in
several European countries, notably in Italy,
and similar efforts are underway in the US and Japan.