If you are living near coastal regions or whenever you visit the coastal region, you can see seawalls. Have you ever wondered why they are built there? Here is the answer: Continuous waves are often a threat that erodes the coastline on any beach, causing loose sand and heavy stones to crash against each other. By constructing a seawall, you can achieve shoreline protection.
In today’s Brick & Bolt’s blog, you are going to understand what seawalls are, their types, and other aspects regarding seawalls.
What are Seawalls?
A seawall is a protective wall or barrier that is used to achieve coastal protection by minimising the disruption and damage caused by hurricanes, tsunamis, waves, tides, and other natural catastrophes. Sea walls prevent storm surges and overturning waves. Ultimately, they stop the land from sliding by helping coastal areas hold onto soil that might otherwise be lost or disturbed over time. Additionally, they prevent water damage from occurring to commercial and residential properties as well as other coastal resources.
Benefits of Seawalls
The following are the top advantages of building a seawall:
- Seawalls offer a frontier between the sea and the land.
- The safety provided by a seawall promotes investment within that area.
- Proper maintenance and timely repairs ensure that seawalls remain durable for a long time.
- Seawalls can be easily modified, repaired, or adjusted by professionals to make them suitable for changing weather conditions.
- By lowering and preventing shoreline erosion and flooding, seawalls play a part in coastal stability.
- Seawalls improve safety for residents and visitors spending time closer to the shore.
- These structures help protect the environment by preventing soil damage.
- Seawalls also protect wildlife from being displaced into the water due to erosion.
Types of Seawalls
There are mainly 8 types of seawalls based on the material used to construct them:
1. Timber seawalls
2. Cobblestone seawall
3. Concrete seawall
4. Sheet pile seawalls
5. Steel seawall
6. Riprap
7. Vinyl seawall
8. Composite seawall
1. Timber Seawalls
Timber seawalls are made up of wood. They help to avoid soil erosion around your property. Timber seawalls create an aesthetically natural look but require regular maintenance. The seawall erosion rate depends on the environment and weather conditions; you have to replace them regularly.
2. Cobblestone Seawall
The cobblestone seawall is made up of huge rocks/stones heaped over gravel and small stones, which are included in mortar. They are aesthetically beautiful and are usually constructed in less challenging places where the wave motion is weak.
3. Sheet Pile Seawalls
Sheet pile seawalls are rooted deeply in the soil and reinforced with huge boulders at the base to provide additional strength. While these seawalls may not be as visually appealing as other types, they work incredibly well to stop soil erosion and divert waves. For regions that experience mild to moderate wave action and soil erosion from strong storms, sheet pile seawalls are perfect.
4. Concrete Seawall
Generally, concrete seawalls are constructed with large blocks or with reinforcement concrete. Compared to other types, concrete seawalls are highly durable and require minimal maintenance. Wherever heavy sea waves often cross the shorelines, concrete seawalls are used. The panels that are used to construct this seawall can be made to match the desired appearance or they can be made to reflect the general design of the construction.
5. Steel Seawall
Steel seawalls are a reliable option because steel is resistant to a wide range of weather conditions. Steel seawalls are a smart choice when considering installation costs and life span. But be aware that steel will eventually rust or corrode, particularly if it is exposed to saltwater.
Before building a steel seawall, it’s also crucial to keep in mind that steel can be quite difficult to install and move, and some sensitive regions may need the use of heavy equipment.
6. Riprap Seawall
Riprap seawall is one of the general types of seawall, and it includes small and large stones in its general composition. Sometimes, chunks of concrete can also be used to prepare them. Generally, these types of seawalls are used on river banks or armour coastlines.
Riprap can scatter the waves’ force before reaching the soil behind the rocks. They are also employed to prevent soil erosion and to reinforce the bases of existing seawalls.
7. Vinyl Seawall
Vinyl seawall panels are less susceptible to corrosion and have a lifespan of around 20 years. Hence, they are used most of the time. They avoid erosion throughout the property. They are mainly used during emergency weather conditions. With regular inspection and proper maintenance, you can extend the seawall’s lifespan while preparing financially for its replacement.
8. Composite Seawall
The composite seawall offers the best defence against storm surges and coastal erosion as it combines the most favourable qualities of different materials. They are highly durable and resistant to corrosion.
Composite materials won’t rust, rot, or degrade like wood or concrete when exposed to sea elements because they are constructed from materials like fibre glass-reinforced polymers (FRP). Seawalls, when combined with tie-backs put deep into the soil, need minimum maintenance and may survive direct strikes from floating debris during hurricanes. With a composite seawall in place, homeowners can rest assured that their property and family are safe from even the biggest storms.
Key Factors in Seawall Design
In seawall engineering, there are numerous factors that influence the design of seawalls. The following are some of the most important considerations:
- Wave Energy and Direction: The design of the seawall should consider wave energy and direction. The wall can become damaged by waves that come from the front or begin to erode from waves that have come down from the side.
- Water Depth and Currents: If the water out front is very deep, for example, or if there are strong currents that could undermine a new seawall, the design would be affected. This may require the structure to be more substantial in deeper water or stronger currents and may also need further reinforcement.
- Coastal Geology and Sedimentation: The stability and durability of the seawall depend upon the rock and soil underneath it. Sedimentation, or the accumulation of sand and sediment, will also play a role in designing your seawall.
- Environmental Factors: The seawall design must also consider environmental factors like tides, storms, and sea level rise. A seawall that is unprepared for these powerful forces will crack and eventually collapse.
- Cost and Maintenance: It might cost a fortune to design and erect a seawall, only for it to be in constant need of repair. Seawall design needs to consider these factors, as well as the costs and benefits, far into the future.
- Community and Economic Factors: The demands and concerns of the neighbourhood and local community, as well as any potential economic effects of the project, should be considered in the seawall’s design.
Every single property, which can be a beach house, commercial building, or other building, is a result of the hard work and dedication of people. Seashores have millions of memories. Each life staying near a coastal region deserves a protective and joyful life. Many environmental challenges, like rising sea levels and stronger storms, cause issues for coastal living, and investing in seawalls is a major step in safeguarding coastal regions for future generations.