Cofferdam are temporary embankments constructed across bodies of water, allowing water to be pumped out from the enclosed area. Once a Cofferdam is in place, workers can carry out excavation, maintenance, concrete pouring, and other tasks.
CHEC GOLD Engineering has an experienced design and construction team that can provide Cofferdam design, material procurement, fabrication, and supply services in the Hong Kong region.
Cofferdam Design
cofferdams, also known as Seawalls, are constructed to expose a water body after water has been pumped out to facilitate the construction of docks or other hydraulic projects. Cofferdam are made by driving piles into the riverbed to form a waterproof barrier. Vertical piles are secured in place by horizontal framing components made of heavy timber, steel, or a combination of both.。
The sides of Cofferdam must be strong and well-supported to withstand the impact of heavy excavation buckets and the lateral forces from surrounding water when internal water is pumped out.
Most Cofferdam are typically categorized into several types
- Cantilever Sheet Pile Cofferdamsrock fill
This type of cofferdam is better suited for smaller depths of water, up to 18 feet. They can be constructed of wood, concrete, or steel. Wooden sheet pile cofferdam is suitable for up to 9 feet, steel sheet pile is suited for up to 18 feet head of water, similar to concrete, which suitable when headroom is limited. They are bored and cast in place and are to be used to avoid noise and vibration.
- An Earth Embankment Cofferdam
This type of cofferdam is suitable for high heads of water with low velocity.The embankment is provided with a free board minimum of 3 feet to prevent overtopping by waves.This type of cofferdam requires large base area and is adopted when an area of excavation is very large.
- Rock-fill Embankment Cofferdams
This cofferdam type is made of rock-fill. A typical section rock-fill cofferdam is better than the earth fill. These are very previous and are usually provided with an impermeable membrane of soil to reduce seepage. The crest and upper part of the impermeable membrane are provided with a rap to protect against the wave action.
- The Double-Wall sheet pile Cofferdam
This type of cofferdam is suitable when it is required to exclude water over 36 feet. This consists of two straight, parallel vertical walls of sheet piling tied to each other, and the space between them is filled with soil. Double-Wall sheet pile cofferdam higher than 7.5 feet should be strutted.
- Cellular Cofferdams
A cellular cofferdam is constructed by driving sheet piles of special shapes to form a series of cells. The cells are interconnected to form a watertight wall. This type of cofferdam is filled with soil and, as a result, provides stability against lateral forces. There are two types of cellular cofferdams, namely diaphragm type, and circular type.
If you are looking for competitive and high-quality contractors for geological structural design and seawall construction in Hong Kong, please send your detailed requests to：contact@checgold.com , we are ready to answer any questions related to your project.
