1st Croatian Conference on Earthquake Engineering 1CroCEE 2021

The knowledge of earthquake load in the last 50 years has been changing according to the results of the research. In national codes and provisions of European Union, Japan, U.S., duration of most bridges is supposed to be 50 years. Thus, bridges built 30 or more years ago are designed to load that is different from today's knowledge of earthquake load. Many bridges which were built before 1970s which are still in use in either Europe or Japan or the U.S. have been designed with little or with no any consideration for seismic demand. Majority of these bridges lack the ductility and strength to resist earthquakes. Meanwhile strong earthquakes have revealed all vulnerable places and wrong detailing on almost all bridges built in seismic regions more than fifty years ago. After the 1971 San Fernando earthquake the U.S. for the first time in the world started seismic retrofit programs for bridges. Japan also started similar programs, especially after the 1995 Kobe earthquake. European Union may not be out of this global problem and must have own retrofit programs for bridges. Thousands of existing bridges all over the word built more than fifty years ago in earthquake zones are still in operation waiting to be retrofitted in order to withstand earthquake loading defined as a result of up to data of research. In this sense in this paper some solutions, recommendations and comments for retrofitting and rapid recovery of bridges after earthquake using the latest concepts for structural upgrading is presented as the main goal to contribute to the knowledge for an earthquake resilient society.