This contribution addresses the seat length required to avoid unseating of bridge girders under strong earthquakes. In the investigation simulated ground motions according to the Japanese design spectrum for soft soil site are applied. The analysis of two adjacent bridge structures is performed using a combined finite element and boundary element method. The results reveal that current design specifications can strongly underestimate the required seat length, especially when the adjacent bridge structures interact unequally with their common ground.
Unequal soil-structure interaction effect on seismic response of adjacent structures