Urban Bridges with Precast Prestressed Elements, Mexico

In the last nine years, the Mexico City authorities have constructed more than 30 large urban bridges with very similar characteristics, which differ from the bridges that had been built in previous years. Since 1987, new structures must fulfill tougher seismic requirements and the seismic-resistant structural elements must have more capacity compared with the requirements of older codes. This situation compels engineers to design new forms of structures. The final designs of the bridges had to be adapted to different configurations in order to take into account water and sewage supply facilities, telephone lines, gas and petroleum ducts, electricity lines, existing streets and buildings, etc.