![]() These eddies also develop in the case of oblique wave approach.īy modifying hydrodynamic conditions, the breakwaters mainly affect the morphological conditions in two ways ( Vaselali and Azarmsa, 2009): 1) The littoral transport in the lee side of the breakwater decreases due to wave attenuation and weakened tidal currents in the area sheltered by the breakwater, which causes trapping of sand behind the breakwater depending on the local setting. The wave set-up on the foreshore is less in the sheltered area than outside, which generates local currents towards the sheltered area along the foreshore from both sides of the breakwater so that two eddies develop ( Thomalla and Vincent, 2004). Wave-overtopping of submerged or low breakwaters will cause an additional supply of water in the area behind the breakwater, and consequently some compensation currents running out the sheltered area. However, as the waves diffract into the sheltered area, a complete shelter cannot be obtained. The breakwater shelters partly from the waves. Thus it is vital that the coastal impact of breakwaters is taken into account when carrying out an environmental impact assessment for a port ( Thomalla and Vincent, 2003 Sane et al., 2007). Breakwaters often cause accumulation in the lee zone and results in erosion effects in adjacent regions. There is a wide variety of breakwaters, including detached breakwater, emerged breakwater, submerged or low-crested breakwater, floating breakwater and so on. Generally, breakwater is a coast-parallel structure close to the surfzone. The breakwaters slow down the northward current during ebb tide, which causes the accumulation of pollutants.īreakwaters are widely used to protect coastal areas, such as ports and ship wharf, from wave action. However, the self-purification ability of Laizhou Bay is significantly reduced according to the conservative substance transport model, especially in the southwest (about 100 km from the Guangli Port to the estuary of Xiaoqinghe River), where the water exchange rate decreases by 10% – 20%. The directions of currents during flood tide and ebb tide veer less than 20 degrees, and a maximum change in speed of (0.87 ± 0.1) m s −1 occurs in between the breakwaters during ebb tide. ![]() The changes mainly occur in the region near the port (about 20 km 2 in area). The results show that the construction has minor influences on the tidal currents. Tidal flow field and conservative substance transport are simulated by a two-dimensional hydrodynamic model MIKE21 to assess the impact of breakwaters on the hydrodynamic environment. Inspection plans, therefore, should take into consideration the critical elements of frequency of inspections and the thoroughness, completeness, and quality of work.Abstract: The construction of two sand breakwaters in Guangli Port might cause changes to the marine environment of Laizhou Bay. The importance of these inspections cannot be overemphasized because the effectiveness of any maintenance program will always depend on how often and how well these checks and services are performed. The detection technologies that comprise the waterside breakwater system are also subject to the harshness of weather which can affect performance.Īll floating breakwater mooring components, either in use or in storage, must be periodically inspected to determine their current material condition and their future maintenance requirements. Metal components of a breakwater system are subject to corrosion. These connections are subject to continuous movement, possibly resulting in fatigue damage and failure of the connections. Floating breakwater usually consists of a line of individual floating dock system elements connected by cables or other devices.
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