FR2569435A1 - Flexible cofferdam - Google Patents

Abstract

The invention relates to a flexible cofferdam making it possible to exclude water from river or offshore works. It consists of a membrane 1 prolonged by a flap 2 and anchored laterally in the side walls by means of folds 3 inserted in recesses and put under pressure in order to obtain mechanical locking and watertightness. This system is more particularly intended for installing cofferdams on locks and dam passages.

Description

 The present invention relates to an improvement made to the cofferdam system.

 Maintenance work on maritime and river works, locks or dams for example, requires putting out of water by installing a removable cofferdam, then exhaustion.

 This cofferdam must be easy to use and easily removable.

It should only require a minimum of manpower and material for the operations of installation or withdrawal.

 Currently it is generally made up of pieces of wood, or metal panels bordered with wood, coming to lean one on the other and sliding at their end in grooves reserved in the bajoyers, abutments, or piles; unless placed vertically, their lower ends engage in a groove and they are supported in the upper part on a beam placed for this purpose, transversely in the pass to be batarded.

 These conventional methods are characterized by heavy and rigid parts, requiring a large staff and very often a pontongrue for the implementation.

 The object of the present invention is to overcome these various drawbacks by offering the possibility of a light cofferdam, easy to set up.

 According to the present invention the cofferdam is composed of a sheet of flexible and resistant material, of common section (1), intended to obstruct the pass, terminated in its lower part by a flap in excess length (2) and in lateral parts by a device (3) for anchoring (4).

 Figure 1 shows a cross section of the cofferdam.

 Figure 2 shows a longitudinal half-section of the bastard pass.

 Figure 3 shows in perspective this bastard pass.

 I, es 4 and 5 show two types of lateral anchoring.

 The membrane (1) is called upon to be waterproof and to resist the mechanical forces due to the pushing of water. It will advantageously be con sectioned as well as the flap (2) from synthetic flexible fabric, polyamide for example, multilayer coated with a mixture of synthetic products, of the elastomer type for example, the fabric giving it mechanical strength, and the coating and protection against external aggressions.

 The flap (2) can be retained by judiciously distributed straps fixed on the one hand to the end of the latter and on the other hand to the body of the membrane, so that during installation, it remains imperatively on the outside of the cofferdam. These straps will be provided with sufficient flexibility so that the deformation of the membrane has no influence on the flap, by means of these.

 The anchoring (3) can be achieved by inserting a tight fold or containing a tight tight seal (4) in an appropriate section reservation made in the bajoyers, then by inflation with a fluid, or filling by any body in order to lock the anchor in the reservation. These elements will advantageously be made from materials similar to the previous ones.

 The system according to the invention is more particularly intended for the bastarding of locks and dam passes.

Claims (5)

1) Flexible cofferdam able to be placed transversely in an obstructing pass, on any water structure, intended to keep part of it out of water; characterized in that it consists of a flexible and resistant Inembrane (1) whose sealing is ensured by gravity by deformation in the lower part, and by lateral fixings. 2) Cofferdam according to claim 1 characterized in that the lower seal can be ensured by the pressure exerted by water on a flap in excess length resting on the submerged raft of the structure, outside the cofferdam. 3) Cofferdam according to claim 2, characterized in that the flap is maintained, during the establishment, of the outer side by flexible straps connecting the end of the latter to the membrane.  t) Cofferdam according to one of claims 1 to 3, characterized in that the lateral tightness, and the resumption of the forces due to the pressure of the water- retained by it can be achieved by lateral anchoring in the bajoyers . 5) Cofferdam according to one of claims 1 to 4 characterized in that the lateral anchors can be made by inserting a fold of the membrane in a reservation of suitable shape made in the bajo- -ers to the right of the cofferdam, and blocking by an appropriate expansive means, 6) Cofferdam according to the one of claims 1 to 5 characterized in that the pleats intended for anchoring can be made waterproof and swollen or filled with a body or a fluid.  ,) Cofferdam according to one of claims 1 to 5 characterized in that the folds intended for anchoring can receive a sealed cylinder intended to be inflated or filled with a body or a fluid, this cylinder locking the fold at the bottom of the reservation, and its pressurization allowing the resumption of mechanical forces dQs at the pressure of the water on the cofferdam. 8) Cofferdam according to one of claims 1 to 7 characterized in that the waterproof anchoring structures can be advantageously inflated with water, and thus pressurized by a fluid known to be incompressible and more widely available near such a work.