Abstract: A process for the formation of an artificial seaweed bed comprises depositing a structure as an artificial fish reef in the sea. According to the present invention, the structure is made of a glassy material having a specific composition, or a surface of the structure is covered with the specific glassy material. The glassy material contains silicon in an amount of 30 to 70 wt. % in terms of SiO.sub.2. The glassy material further contains sodium and/or potassium in an amount of 10 to 50 wt. % in terms of Na.sub.2 O and/or K.sub.2 O. The glassy material furthermore contains iron in an amount of 5 to 50 wt. % in terms of Fe.sub.2 O.sub.3. All or a part of the iron is present in a ferrous state. The glassy material contains the ferrous iron in an amount of not less than 1 wt. %.

Abstract: A stair-like revetment structure is formed by using sloping blocks. At the rear end of the block main body having an approximately rectangular and a rearwardly sloping flat step are provided rear engagement pods opening like a wedge at the rear of the main body and front engagement pods having an approximately same shape as the rear engagement pods extending adjacent a concave portion at the center bottom of the front of the main body, the concave portion being provided between the front and the rear engagement pods. This results in a low cost simplified sloping block structure.

Abstract: A wave dissipating wall is formed of a plurality of wave chambers comprising a plurality of horizontal plates and vertical partition walls opening toward the direction from which waves come in. The ends of the walls dividing the chambers are wider than the remaining parts of the walls and the front walls comprise semi-circular curved surfaces extending toward the direction from which the waves come in order to introduce the waves into the chamber having a wider width than the entrance formed between the respective front walls and to let the waves circulate within the chamber by the energy of the waves, thereby increasing the friction resistance between the waves and the walls as much as possible and achieving an efficient diminishing of the wave energy.