Seament Shoreline Systems, Inc.
8229 Lighthouse Lane
King George, VA 22485
L walls were designed by Ed Veazey to protect his property along
the Potomac River that was facing waves from a 14 mile fetch over
the Potomac River. Large waves were undercutting the 40 foot high
bank and causing repeated landslides that were then washed away
by the waves and the process repeated.
Living on the water all his life he had seen the standard wooden
bulkheads used to protect banks consistently fail from the pressure
of the soil pushing against the walls and snapping the deadman or
tiebacks that were used to prevent this. He designed the L wall with
a cantilevered return "shelf" acting to prevent the wall from tipping
out, it's center of gravity is such that it wants to lean back into the
slope even without the weight of the dirt on the wall.
Above are views of an L wall being installed, showing the large
excavator need to move and install them, a corner wall butted up
against a neighbors wooden wall, and the back shelf of the wall
before backfilling with a roll of filter cloth about to be spread against
the back of the wall. A finished installation with steps down to the
beach show how an L wall can protect your property from Nature's
worst and still leave a beach in front of the wall that a rock revetment
would otherwise cover with stone and filter cloth.
Here a view of a rock revetment which covers 10 to 15' of the beach
and is vulnerable to slumping from high tides liquefying the graded
slope it rests on or from large waves moving the rocks about as they
do not support their neighbors like an L wall.
The next picture shows a vinyl wall being installed in front of a rotten
wooden wall. They both use tie back seen above to stop the
pressure of earth and water from pushing them outward. They are
also both limited in their lifespan as treated wooden boards and post
are used as structural members which rot over time.
L wall bulkhead/ retaining wall:
Each wall is attached to it's neighbors with steel channel bars and
tongue and groove joints in the concrete along the horizontal and
vertical edges. The Eight thousand pounds units act as one large
unified mass that withstand the huge force of the waves that slam
into them. A splash plate that extends out near the base of the wall
helps deflect out the reflected wave energy to lower scour at the
base of the wall. A buried key down below the beach stops the wall
from moving out from the pressure of the slope behind it.
The L wall bulkhead system installations have weathered over 14
years of stormy weather and hurricanes in the Chesapeake Bay
area. Over a mile and a half of walls have been installed over that
time. Each installation has been hit by storms that caused major
damage and failure to neighboring rock revetments and wood and
vinyl bulkheads while the L walls have come through unscathed.
L Walls are made at the Oldcastle precast concrete plant. They are
made of VDOT bridge grade concrete with a minimum of 6000 psi
concrete with fiber and rebar support inside.
They are set in place, bolted together, backed with filter cloth and
back-filled with sand, gravel and soil to act as a run-off filter for
surface water pollutants.
The outcome is magnificent! The large integrated mass of concrete
and sand resists destructive storms and floods, following Newton's
Law of force equals mass times acceleration ( F= MA ).
Copyright 2009 Seament Shoreline Systems, Inc. All rights Reserved.