Annular monoblock foundations are increasingly used in bridge pillar construction, where they guarantee high bearing capacities, safety, speed and ease of execution.
Here we illustrate their main design and calculation features as well as the constructive modalities from some recent examples of Italian road bridges.
The advantage of this foundational typology is evident in the realization of high and medium span bridges in water, where the cost of construction is particularly optimized.
The facilitation is significant since the construction operations are all from above and dry compared to the classic foundations of piles and pile cap that require the construction of provisional sheet pilings in water or other shafts, to allow the construction of the pile cap under the water level. These last elements generally interact negatively on hydraulic behavior around the pillar; this interaction is considerably reduced with annular monoblock foundations.