Over time, the cumulative stress of speeding boats and excessive wave action can cause a bulkhead’s berm on the waterside to deteriorate. This can allow the bulkhead’s toe to slip outward. Building up the berm and adding riprap can correct this.
Also on the waterside are “weep holes” drilled to facilitate efficient drainage and prevent the buildup of hydrostatic pressure. These should be inspected regularly. Contact Boat Dock Bulkheads now!
Bulkheads are marine structures that protect waterfront properties from erosion, flooding and damage. They serve as an economical shoreline boundary that separates upland marina areas from wet slips for boats. Bulkheads are designed to withstand the forces of nature, but they need consistent monitoring to ensure their longevity and safety.
A berm, or slope of sediment on the water side of the bulkhead, is essential for supporting the toe and stabilizing the structure. The berm also serves as a base for anchor pilings that extend out of the lagoon and serve as the bulkhead’s foundation.
The berm should be kept free of obstructions such as debris, vegetation and sand that could impede the flow of water or restrict hydrostatic pressure buildup in the system. Additionally, the berm should be checked and replenished regularly with rock or gravel fill material to keep it at an optimal level.
Over time, the cumulative stress from speeding boats or excessive wave action can cause the berm on the water side of a bulkhead to deteriorate, potentially allowing the toe to slip outward. Signs of a slipped toe include a visible twisting or rotation of the concrete cap, cracks in the cap and gaps that open up between the bulkhead and dock (if applicable). In minor cases, this may be corrected by building up the berm with riprap or placing bags of dry concrete mix in order to stabilize it again.
Like seawalls, bulkheads can be constructed of a wide variety of materials including stone, wood and concrete. In general, the more durable, longer lasting and attractive marine construction solution is a vinyl bulkhead with interlocking panels that are made of long lasting, heavy duty, exterior grade vinyl that won’t corrode or rust. Many marine construction companies offer this type of bulkhead installation as part of their dock and pier construction services. They’ll perform a full site assessment to determine soil conditions, water depths and current patterns to design the best bulkhead for each property.
The Panels
Bulkheads protect homes, docks and other waterfront structures, as well as the shoreline and natural environment. Their main job is to reduce erosion, flooding and marine growth, while preventing sedimentation from washing into the water. They also keep waterfronts elevated and clear of rocks and other hazards, making them safer for pedestrians.
A bulkhead can be constructed from wood, concrete or steel, depending on the design and materials selected. Construction usually involves securing permits, clearing the site and forming and pouring the bulkhead panels on-site. Some types of marine construction contractors offer precast bulkhead sections that can be installed faster and with less disruption than traditional on-site construction.
In general, a bulkhead can last for decades with regular maintenance. However, there are certain things that can cause its structural integrity to deteriorate over time. Some of these problems are a result of human activity, such as speeding boats or excessive wave action that can affect the berms and sands that hold the bulkhead in place.
Other issues may occur due to natural changes in water levels or storm activity. Poor drainage can lead to the buildup of hydrostatic pressure against panel joints, which could eventually cause them to separate. Diverting stormwater away from the panel joints and keeping weep holes on the water side of the bulkhead clean of soil can prevent this problem.
For additional stabilization, the toe of a bulkhead can be supplemented with large stones known as riprap. A sand or concrete sheathing is often used on the land side of the bulkhead to help reduce erosion and support the berm. On the water side, the bulkhead’s tie rods are anchored at engineered intervals with “wales” or “deadmen” to provide extra resistance.
The Tie Rods
Bulkheads are constructed of a variety of materials. Typically, they consist of a concrete slab at the toe, a berm of earth reinforced with rock or riprap and a series of panels made of concrete, PVC or a combination of natural and synthetic materials. The panels are positioned and connected by a series of “soldier piles” or “wall piles” that are made of wood, steel or concrete. The tie rods extending from these support piles provide the primary structural strength of a bulkhead, and they are often capped with a concrete collar for added durability and a finished appearance.
Tie rods can oxidize and corrode over time, weakening the structure of a bulkhead or seawall. Signs of this include a deteriorating cap, wavy or sagging panels, and settlement of the backfill on the upland side of the wall. Marine construction contractors can often correct the problem by adding supplemental helical tiebacks to keep the bulkhead in place and prevent premature deterioration and failure.
The area behind a bulkhead or seawall is often backfilled with soil or gravel to add support and stability to the structure. In addition, drainage systems are installed to prevent water buildup behind the bulkhead and reduce hydrostatic pressure that can cause it to fail.
A well-constructed bulkhead or seawall safeguards waterfront property from erosion by water and may also mark a boundary line between two properties. Like other waterfront structures, however, bulkheads and seawalls require periodic repairs to maintain their functionality and withstand environmental conditions. For the most part, these repair projects are relatively inexpensive and can be performed by a qualified marine contractor. For more information about repairing or replacing your bulkhead, please download our free guide.
The Anchor Pilings
The main function of a bulkhead is to maintain water depths and provide stability to the shoreline. In order to do this, they are designed based on the soil conditions found both on and behind the wall as well as the expected load that is placed upon it over its expected service life. If these conditions change significantly it can impact how effectively a bulkhead functions.
As with any structure that is subject to a large amount of lateral forces, it is important for bulkheads to be regularly monitored and assessed. Generally this will be done by a marine construction contractor. The contractor should inspect the bulkheads on a regular basis to ensure that they remain structurally sound and that they meet the intended load capacity.
Marine construction contractors are able to install bulkheads with various materials depending on the clients needs and budget. Some options include CCA (pressure treated lumber), concrete or composite piles. All of these have benefits over traditional timber piles. The use of concrete and composite piles also help to minimize environmental impacts compared with traditional timber.
A typical dock piling installation involves jetting, where a high-pressure water pump is used to create holes in the bottom of the lake or river to set the pilings. The jetting process is much faster than the hammering method of installing timber piles.
A dead man piling is then installed behind every support piling in a bulkhead to anchor the back of the structure. A 5/8” galvanized sag rod is then installed from the support piling to the dead man to connect them together. Many larger seawalls and bulkhead projects are moving away from traditional dead-man anchors to screw pile tiebacks as these have the added benefit of being able to be driven beneath existing hardscapes, mature landscaping and underground utilities greatly reducing remedial costs.
The Cap
Over time, the cumulative stress from speeding boats and excessive wave action can cause a bulkhead’s berm on the water side to deteriorate and give way, allowing the toe of the structure to slip outward. Signs that this has happened include visible twisting or rotation of the concrete cap, cracks in the berm and gaps that open between the toe and rest of the bulkhead. If the movement is minor, a marine construction contractor can correct it by building up the berm and supplementing it with riprap.
Bulkheads are vital components for waterfront property owners, decelerating erosion and facilitating the construction of docks, piers, and homes. However, these structures are not without their challenges and are often subject to a number of common problems that could lead to costly repairs or replacements. By learning more about the common issues that can affect bulkheads and taking steps to prevent them, property owners will be able to preserve their investment and protect their lakefront living spaces for years to come.
When it comes to the material that is used to construct a bulkhead, there are many options available, each with its own set of pros and cons. The most commonly used material is CCA (Chemically Treated Wood), which has been pressure-impregnated with a preservative that makes it resistant to marine organisms that can cause decay. While this type of lumber is generally cost-effective and has a service life of 30+ years, it does have some disadvantages, including limitations on its use in hard substrates and reduced strength characteristics at higher wall heights. A more recent, alternative option is vinyl sheet piling. This product is extruded from a weatherable, UV-resistant polyvinyl chloride and has been rated to resist rot, termites, marine borers, fungus and ultraviolet deterioration on a pro-rata basis for a minimum of 50 years.