Search results
Results from the WOW.Com Content Network
Schematic cross section of a pressurized caisson. In geotechnical engineering, a caisson (/ ˈ k eɪ s ən,-s ɒ n /; borrowed from French caisson 'box', from Italian cassone 'large box', an augmentative of cassa) is a watertight retaining structure [1] used, for example, to work on the foundations of a bridge pier, for the construction of a concrete dam, [2] or for the repair of ships.
A suction caisson can effectively be described as an inverted bucket that is embedded in the marine sediment.Attachment to the sea bed is achieved either through pushing or by creating a negative pressure inside the caisson skirt by pumping water out of the caisson; both of these techniques have the effect of securing the caisson into the sea bed.
[citation needed] The design typically consists of a large volume caisson based on the sea floor merging into a monolithic structure, which is offering the base for the deck. The single main leg is surrounded by an outer breaker wall perforated with so called Jarlan holes. This wall is intended to break up waves, thus reducing their forces.
A breakwater structure is designed to absorb the energy of the waves that hit it, either by using mass (e.g. with caissons), or by using a revetment slope (e.g. with rock or concrete armour units). In coastal engineering, a revetment is a land-backed structure whilst a breakwater is a sea-backed structure (i.e. water on both sides).
Other key factors in offshore construction are the weather windows which define periods of relatively light weather during which continuous construction or other offshore activity can take place. Safety of personnel is another key construction parameter, an obvious hazard being a fall into the sea from which speedy recovery in cold waters is ...
The wavemaker frequently consists of a translating or rotating rigid wave board. Modern wavemakers are computer controlled, and can generate besides periodic waves also random waves, solitary waves, wave groups or even tsunami-like wave motion. The wavemaker is at one end of the wave flume, and at the other end is the construction being tested ...
When waves travel into areas of shallow water, they begin to be affected by the ocean bottom. [1] The free orbital motion of the water is disrupted, and water particles in orbital motion no longer return to their original position. As the water becomes shallower, the swell becomes higher and steeper, ultimately assuming the familiar sharp ...
Waves can occur on the thermocline, causing the depth of the thermocline as measured at a single location to oscillate (usually as a form of seiche). Alternately, the waves may be induced by flow over a raised bottom, producing a thermocline wave which does not change with time, but varies in depth as one moves into or against the flow.