Posted By:Infra Bazaar
The term underwater construction or commercial diving covers a broad arrangement of activities, at the core. Under water construction plays an important role and it’s not so simple as other construction activities happens. Here the complexity of the project is large as the complete construction activities happen under water. Activities vary greatly but primarily include inspection, bridge and building repair, repair of waste water treatment and equipment installation.
In geotechnical engineering, Pneumatic Caissons are sent to the sea floor and pressurized air is pumped from the surface. Caissons are a watertight retaining structure used for various under water constructions like bridge pier, foundations, construction of concrete dams and for repair of ships. These are constructed in such way that water can be pumped out, keeping the working environment dry. When these piers are to be built using an open caisson it is not practical to reach suitable soil. These friction pilings might be driven form a suitable sub-foundation. These piles are linked by foundation pad upon the column pier which is erected.
Cutter Suction Dredgers
A cutter suction dredger is a stationary or self-propelled vessel that uses a rotating cutter head to loosen the material in the water bed (‘cutting’). A suction inlet located beneath the cutter head (known as the suction mouth) is connected by a suction tube directly to one or more centrifugal pumps. The vacuum force at the suction inlet sucks up the loosened material. The suction tube and cutter head are attached to a ladder. The ladder with cutter head is positioned at the fore of the vessel.
This technique is often used to keep waterways navigable, and it’s also used to reload sand on some public beaches, where the sand has been lost because of coastal attrition. This Dredger is mostly used in Americas used to excavate and remove wastage material under the water. For example scoop attached at the end of rope or pole which an operator can draw sediments up from bottom of a dew pond.
The immersed tube is class of underwater tunnel composed of segments, constructed to a different place and floated to tunnel site to be depressed into place and then linked together. The immersed tunnel method has been widely used for about 100 years, and more than 150 immersed tunnels have been constructed worldwide. They mainly serve as road or rail tunnels, but immersed tunnels are also used for water supply and electric cables. Immersed tubes are frequently used in combination with other forms along the tunnel end.
Submarine Multipurpose Excavator "ABYSS"
A remote Hydraulic Excavator also known as Abyss is designed for operation in shallow and deep waters. While the driver can operate from sheltered control room at a distance from the site this excavator can perform under the water up to 100 m depth and can be easily up-graded to reach 1000m depth under the water. This equipment can be easily launched directly from coast or from support vessel. While operation undergoes inside deep waters the excavator requires careful planning and expertise to run it. The applications may vary and have couple of common things while working in environmentally sensitive areas as the machines will be constantly exposed to water.
As per “Einhorn “Under water construction work is a tough field and is a very dangerous job hence, one should follow the safety regulations. It just cannot be compared with a simple construction work. Despite being a tough field to break into, the underwater construction industry can be quite rewarding for those who stick to it. “You either love this business or you hate it – and I’m still in it,” Einhorn says.