Cofferdam Benefits
- Provides water cut-off and allows construction of new structures such as boat ramps, bridge piers, intake structures and drainage pipe within bodies of water.
- Provides water cut-off below mud line to reduce water inflows below base of excavation.
- Sheet Pile can be designed to accommodate project layout, lengths and sizes for a multitude of varying construction requirements.
- Interlock Sealant provides an effective water seal to prohibit the intrusion of water from outside of the cofferdam.
- It can be designed for temporary or permanent use.
Standard Operations
A cofferdam is an enclosure wall built within bodies of water. Once the enclosure is built, it then becomes possible for dewatering of the enclosed work area, making it conducive to begin construction work in a dry area.
These water-tight structures are installed first, and then water removal can begin, and it’s typically done in two phases.
Phase 1: This is your initial phase in which the goal is to remove water from the cofferdam’s interior. It’s during this phase that water can be pumped freely without restrictions, allowing for the development of differential pressure, usually at 15 feet. This is what allows the interlocks to tightly close. If constructing a large cofferdam, you would implement this same process, but after that, the dewatering process would continue but at a five feet rate per day until a dry and stable work area has been achieved.
Phase 2: This is the dewatering process where you’re working to lower and control the groundwater in the foundation. The well-point system is usually done to achieve this, mostly for large cofferdams where the depth of the excavation isn’t beyond 40 feet.
Cofferdams can be made from a variety of materials but typically are comprised of sheet piles that are often made from steel and supported by components including internal braces and wales (but can also be made from natural materials like wood or Timber). Steel sheet piles are preferred because they’re good for heavy-duty projects and are more effective in dewatering a work area to prevent the risk of potential flooding, which would then put workers at risk and cause project delays.
There are many types of cofferdam options to choose from based on your project needs. There are single and double-walled sheet piles, cellular and box-type, braced and earthen, and many more. But regardless of the type of cofferdam you need, you want to make sure you’re choosing one that is structured and designed for stability. This is extremely important because it’s the factor that determines how sturdy and reliable your cofferdam will be in protecting the work area.
Key Features and Benefits
- Materials are cost-effective and eco-friendly due to being reusable
- Easy to install and uninstall
- Provides a safe environment for workers due to dewatering efforts
- Sheet pile can be laid out to meet project design specifications
- Can be installed for short-term or long-term use
- Dewatering allows for the construction of marine-based structures including boat ramps, ship repairs, bridge repair, and building ships
- Allows completion of projects with minimal delays and within the proposed project budget
The Cofferdam Construction Services Solution
Long gone are the days when rocks and earth were used as the sole materials for cofferdams to seal off surrounding water from a specific area. Due to technological advancements in marine construction, cofferdam construction services are your temporary or permanent water control solution.
Company & Overview
Blue Iron Foundations & Shoring, LLC, has been trusted for over a decade to install design build & pre-designed sheet pile systems including temporary earth retention, floodwalls, and cut off walls. We have an extensive equipment fleet that gives us flexibility to install sheet pile using vibratory, impact and/or vibration free methods to suit any project need. Sheet pile is widely used for shoring systems in high ground water, seawalls, retaining walls, floodwalls, basement walls for parking structures, cut off walls and drainage canal walls. Sheet pile are capable of cantilevering but can also include bracing and/or tie backs to allow retention of deeper excavations.
