The Cause of Soil Holes Behind a Seawall
As seawalls age, soil often migrates through the vertical panel joints and weep holes. During construction, a geotextile filter fabric is usually installed on the landward side along the vertical panel joints and weep holes to prevent the migration mentioned above. Over time, however, filter fabric begins to deteriorate and becomes ineffective. Soil migration then occurs during every water event (rain, irrigation, daily tide activity, storm surge, etc.).
Holes Behind a Seawall Indicate Structural Stability Issues
Holes forming behind your seawall are a very big deal and should be considered a red flag that cannot be ignored. A slow process initially, soil migration eventually leads to void formations on the landward side of the seawall. Void formations jeopardize the overall stability of the seawall structure. The loss of structural stability can lead to movement of the wall itself. As the structure slips and moves, damage to seawall caps and panels occur. In addition, resulting stress on the supporting seawall tie-rods and deadman anchors can lead to complete failure of the entire seawall.
If you see holes behind your seawall, you should contact a qualified seawall repair contractor as soon as possible.