Pressures on Gabion Boxes as Artificial Reef Units

Naturally occurring shoals and near-shore reefs act as good wave attenuators. Artificial reefs have been looked into as potential solutions for creation of surf waves. Recently, artificial reefs are being examined as soft solutions for coastal protection. Conventional hard approaches like construction of sea wall, groins, revetments, bulkheads and break waters have been successful over the past. However, they may sometimes create adverse impacts on the coastal environment. Thus, employing artificial reefs for shore protection would yield multiple benefits as they attenuate the waves away from shoreline and does not interact with the shoreline directly. Because of this, they are often called multipurpose reefs. Construction of reefs has been primarily based on geo bags and geo tubes. Sometimes, rubble mound construction has been used. However, there are construction and handling difficulties. Hence, gabions may be considered in artificial reefs due to their ease of construction and porous nature. Gabions also reduce the construction time, hence making it suitable to construct during adverse weather window. The porosity of gabions may also add favorable effects on the near shore environment. On the other hand, several installations of artificial reefs over the past decade have faced severe stability issues. Since literatures relevant to artificial reef are scanty, the present study brings out the experimental measurement of pressures on Gabion Boxes as artificial reefs. In order to relate the pressure to stability, pressures are measured over units at critical locations. An attempt has been made to use the measured pressures to obtain forces and thus stability factors of Gabion Box units in reef applications. The pressure measurement is made varying, the reef parameters and wave parameters. The purpose of varying the reef parameters (width of reef and height of the reef) is to come out with the optimum configuration of reef for a given wave climate. The pressure measurement corresponding to a particular reef configuration is presented in the paper.