Disclosed is a concrete cover element for a breakwater or jetty construction. The cover element includes a plate portion and two noses. The plate portion lies in the xy-plane and has a thickness. The two noses project in opposite directions from the plate portion and form a single part with the plate portion. The plate portion is to be imagined as being formed from a quadrangular plate whose two opposite plate edges are incised in the middle to form a plate recess, and whose corners located on the first plate diagonal are both cut off along a first secant. The plate portion has a first dimension measured along the first plate diagonal and a second dimension measured along the second plate diagonal. The first dimension is smaller than the second dimension.

There is described a module for an underwater structure. The module comprises a plurality of walls defining a cavity configured such that at least two walls of said plurality of walls confront one another to provide respective stack support surfaces for supporting said module, said walls are substantially parallel to form complementary stack surfaces, such that one stack surface may rest on a surface and the other complementary stack surface provides a rest surface for another module. Two or more walls of said plurality of walls each comprise an aperture providing a conduit through each two or more walls to said cavity, respective apertures of said two or more walls and said cavity configured to provide a water flow path into, through and from said cavity. The water flow path may be considered unconstrained or at least substantially unconstrained in that water ma flow through the apertures and cavity without deviation or interruption other than by the module or cavity walls. In stacked formation an aperture may be occluded or partially occluded but still the module when on its own may provide water pathways which may be considered unconstrained or substantially unconstrained.

A seawall section includes a central hub having an axis extending in a longitudinal direction and three circumferentially spaced walls extending radially from the central hub. Each of the walls is made of cast concrete reinforced with a rebar cage having a plurality of longitudinally spaced pairs of parallel rebars extending radially from the central hub to an end rebar that extends perpendicularly relative to the parallel rebars. Each end rebar is connected to radially outer ends of one of the pairs of parallel rebars. A seawall comprises a plurality of the seawall sections connected together end-to-end with a cable, and connecting plates fastened to adjacent sections. A form for manufacturing the seawall section encloses connected rebars and is filled with concrete.

A seawall section includes a central hub having an axis extending in a longitudinal direction and three circumferentially spaced walls extending radially from the central hub. Each of the walls is made of cast concrete reinforced with a rebar cage having a plurality of longitudinally spaced pairs of parallel rebars extending radially from the central hub to an end rebar that extends perpendicularly relative to the parallel rebars. Each end rebar is connected to radially outer ends of one of the pairs of parallel rebars. A seawall comprises a plurality of the seawall sections connected together end-to-end with a cable, and connecting plates fastened to adjacent sections. A form for manufacturing the seawall section encloses connected rebars and is filled with concrete.

A lost sand collecting apparatus, according to the present invention, comprises: a filling frame which has a plurality of plates, extends in the lateral direction and forms a plurality of filling spaces; and a collecting means which is provided on the filling frame and is positioned so as to correspond to the filling spaces. The plurality of plates are overlapped so as to be parallel to each other and the plates adjacent with a fixed distance therebetween are partly connected to one another. The collecting means can be formed in a flat structure protruding upward from the filling frame and disposed on the back of the filling spaces with respect to the littoral current toward the sea, and comprises a barrier layer or a web layer. The barrier layer or the web layer is curved toward the littoral current toward the sea. According to the present invention, the collecting means enables inhibition of the flow of the littoral current toward the sea and collection of sand moving with the littoral current flowing from the shore to the sea, thereby regulating coastal erosion. Therefore, coastal beaches can be preserved.

A lost sand collecting apparatus, according to the present invention, comprises: a filling frame which has a plurality of plates, extends in the lateral direction and forms a plurality of filling spaces; and a collecting means which is provided on the filling frame and is positioned so as to correspond to the filling spaces. The plurality of plates are overlapped so as to be parallel to each other and the plates adjacent with a fixed distance therebetween are partly connected to one another. The collecting means can be formed in a flat structure protruding upward from the filling frame and disposed on the back of the filling spaces with respect to the littoral current toward the sea, and comprises a barrier layer or a web layer. The barrier layer or the web layer is curved toward the littoral current toward the sea. According to the present invention, the collecting means enables inhibition of the flow of the littoral current toward the sea and collection of sand moving with the littoral current flowing from the shore to the sea, thereby regulating coastal erosion. Therefore, coastal beaches can be preserved.

The Integrated Drain Gate Seawall System (IDGSS) was designed to mitigate flooding due to rising sea water, severe rain and storm damages at costal area or other various waterfront properties like riverbanks, bay, beach, ocean, lake, marsh and low lying areas. The IDGSS has incorporated two functions simultaneously by separating water and land with a flood resilient fixed water barrier wall, but more importantly, has an automatic drainage system, especially for an unexpected severe and prolonged storms; to address the unintended consequence of trapping water inside the pre-existing water barrier walls. Unfortunately, during these severe storms, the trapped water has created a bathtub like scenario by the manmade fixed wall barriers, and causing an insult to an injury to an already devastated storm conditions, due to a lack of drainage systems. To mitigate this type of severe drainage problem, IDGSS was created with a characteristics of a concrete wall blocks, which includes a one-way valve or flap drain gate inside as a single unified structure, with an adjustable one-way valve or flap drain gate specification; with a various shape, sizes, materials and configurations for both one-way valve or flap gate and wall blocks; and adaptable retrofitting mechanisms to meet the site specific topography and special drainage needs. To protect the one-way valve or flap gate drainage system and to allow for an efficient drainage pathway system, the wall blocks are built to withstand severe wind and unpredictable weather conditions to become storm resilient, pressure reducing mechanism within the unlimited combinations of geometrical wall shape and size arrangements. Thus, the IDGSS is a reinforced wall system that can adapt to a specific drainage problem by allowing the trapped water to be returned back to where it came from as long as the water recedes by gravity.

The Integrated Drain Gate Seawall System (IDGSS) was designed to mitigate flooding due to rising sea water, severe rain and storm damages at costal area or other various waterfront properties like riverbanks, bay, beach, ocean, lake, marsh and low lying areas. The IDGSS has incorporated two functions simultaneously by separating water and land with a flood resilient fixed water barrier wall, but more importantly, has an automatic drainage system, especially for an unexpected severe and prolonged storms; to address the unintended consequence of trapping water inside the pre-existing water barrier walls. Unfortunately, during these severe storms, the trapped water has created a bathtub like scenario by the manmade fixed wall barriers, and causing an insult to an injury to an already devastated storm conditions, due to a lack of drainage systems. To mitigate this type of severe drainage problem, IDGSS was created with a characteristics of a concrete wall blocks, which includes a one-way valve or flap drain gate inside as a single unified structure, with an adjustable one-way valve or flap drain gate specification; with a various shape, sizes, materials and configurations for both one-way valve or flap gate and wall blocks; and adaptable retrofitting mechanisms to meet the site specific topography and special drainage needs. To protect the one-way valve or flap gate drainage system and to allow for an efficient drainage pathway system, the wall blocks are built to withstand severe wind and unpredictable weather conditions to become storm resilient, pressure reducing mechanism within the unlimited combinations of geometrical wall shape and size arrangements. Thus, the IDGSS is a reinforced wall system that can adapt to a specific drainage problem by allowing the trapped water to be returned back to where it came from as long as the water recedes by gravity.

A caisson block construction method, including: manufacturing a plurality of bottom caisson blocks having a plurality of first unit compartments disposed consecutively in a horizontal direction; manufacturing a plurality of upper caisson blocks having a plurality of second unit compartments; forming a bottom caisson block structure by installing the plurality of bottom caisson blocks side by side in the horizontal direction; installing the plurality of upper caisson blocks above the installed bottom caisson blocks; filling with rubble the second unit compartment of the upper caisson block positioned above the first unit compartment for rubble and exposed upward; inserting a vertical reinforcing bar module after the upper caisson blocks are installed; and forming a vertical concrete column for joining by casting concrete into the upper part of the second unit compartment in which the vertical reinforcing bar module is inserted.

Disclosed is a crest element in an armor layer assembly of a breakwater. The crest element includes: a central part; two wings extending from the central part in opposing directions along, when placed on a breakwater, the length direction of the breakwater; and a nose extending from the central part in a forward direction transverse to the length direction of the breakwater. The backside of the central part is a vertically oriented, back face facing in a backward direction opposite to the forward direction. The crest element may in particular be used as crest element for armor layers including armor elements of the type having a central part from which: two wings extend in opposing directions, and a tail and nose extend in opposing directions transverse to the direction of extension of the wings. Also disclosed is an armor layer, a breakwater and methods using the crest elements.