Rock Bulkheads / Sea Wall
Type: Man Made, Natural
Stone displays superb structural integrity with the ability to quickly evacuate large quantities of water reducing the pressure placed on the seawall. The space between the stones allows water to escape rapidly to reduce the weight behind and within the structure. The exchange, caused by tidal and ground water movement is a major consideration in any bulkhead application. Rocks are placed in an interlocking pattern which further increases structural integrity. As water inundates a solid concrete wall at high tide, piped drainage systems may not be able to release water quickly enough to avoid “hydraulic push out” or total wall failure. Blocks, laid up in rows may create “hinge-points“ where the wall may be bent forward along a straight line between rows. During times of extreme back-pressure from tidal drop or heavy rains, “hinge points” may contribute to the collapse of the wall. Another reason is that rocks dissipate wave energy much better than a flat surface. This helps to prevent “scour” a major cause of bulkhead failure.