Seismic response of bridges with massive foundations

摘要: Abstract The dynamic response of vehicular overpasses with massive foundations built in highly populated earthquake prone regions is studied to assess the foundation potential being a technically sound mean reduce structural during major earthquakes. study consists on numerical simulations using 3-D finite element models. Two typical supports 23 km long overpass recently north east part Mexico City valley were considered this research. This zone characterized by presence stiff soils comprised dense and very silty sands sandy silts, randomly intercalated clays layers variable thickness. Initially, conventional raft structurally connected four precast closed-end concrete piles was considered. Then, beneficial effect depth assessed. Sets models developed systems evaluated for seismic scenario such as that prevailing at zone, assuming 8.1 M w event, hypothetical 8.7 extreme event. Important attenuations about 39% 48% upper deck spectral accelerations 21% 30% maximum lateral displacements achieved soil improvement cases analyzed. Thus, seem be convenient alternative overall response.