Everyday seawalls and bulkheads are affected by natural forces such as hydrostatic pressure, fluctuating tides, and thermal expansion and contraction. When this occurs, small defects can develop over time causing water from the positive side of the seawall to infiltrate into the soils behind the seawall or bulkhead. When water saturates the supporting soils, the soil’s ability to provide support eventually weakens.
As the tide goes in and out, water levels drop, and a vacuum is created causing the saturated soils to travel from the negative side of the seawall into the body of water. This leads to soil erosion, which can often be seen in the form of small sinkholes immediately behind the seawall. The lack of supporting soils will ultimately lead to structural compromise or failure of the seawall.
The use of injection grouts to rehabilitate seawalls and bulkheads is an economical way to stabilize and bind the soil and prevent further erosion of the structure. Doing nothing can cause the problem to intensify leading to costly repair or more expensive replacement.