BEBO foundations are designed traditionally as for a normal bridge project. The most common types of foundation for BEBO arches are spread footings, with a small number of bridges being built on slab foundations, and on strip footings supported on reinforced concrete piles.
STRIP FOOTINGS
FOOTING ON PILES
SLAB FOUNDATION
SCOUR PROTECTION
If the BEBO structures are used at a creek crossing, the foundations will be subject to the forces of flowing water. Therefore the design of this type of structure considers the probability of scour or undermining. However, the scouring of foundations is not solely a BEBO foundation problem; it is a problem associated with any type of bridge system .
The wide footings and outward thrust of the structure loading for some profiles is self-protecting. These features combined with protective treatment where necessary greatly reduce the risk of undermining.
JOINTS
BEBO arches are placed with a nominal 10mm gap between each unit. The joint is then sealed with a flexible mastic and covered with a filter geofabric to prevent infiltration of soil.
SKEW ANGLES
Standard arch elements can be used to construct bridges at any skew angle. The arch is extended beyond the road boundary and covered with fill.
