PASSAGE FOR RESTORING LONGITUDINAL CONNECTIVITY OF A RIVER

摘要

The invention relates to a passage for restoring the longitudinal connectivity of rivers in front of an obstacle of the type of a submerged crossing or a dam which allows aquatic microorganism migration upstream and downstream in relation to the obstacle built in the river bed and to a process for building the same. According to the invention, the passage is built in the area of an obstacle (A1 or A2), submerged crossing or dam built on a river bed (B) and consists of some submerged channel sections (C) wherein some day light tubes (D) from the outside may be mounted, depending on the ambient suitable to various aquatic organisms, the aquatic organisms being guided towards the inlets and outlets by means of some guiding structures (E and F), i.e. downstream submerged structure and upstream floating structure, respectively, related to the obstacle (A), a section (C) is made of reinforced concrete and comprises a flat invert (1), some lateral walls (2), a cylindrical dome (3), some cross walls (4) which are connected to the walls (2) through cylindrical surfaces (a) and to the dome (3) through spherical surfaces (b), positioned to one another so as to form some rest compartments the inlet and the connection compartment (C1, C2, C3), which communicate to one another through some lower convergent-divergent passage orifices (c) made into the walls (4), at the upper side the compartments (C1) may be provided with some pipes (5) for introducing water jets meant to entrain the slime deposited during the operation if the water of the river bed (B) contains a high suspension percentage, the inlet (C2) may be provided with a cofferdam (6) mounted in a slot (d) driven by means of a mechanism (7) which allows the closing of the orifice (c), when needed, and the dome (3) and the surface (b) may be eliminated, the connection compartment (C3) being provided, at the outside, with a rib (8) by which it is connected to another section (C).