DE102005013179A1 - Device for sealing pressure joint in e.g. underground or open water channel, has rigid element embedded into lower sealing sheet overlapping part of upper sealing sheet from its overlapping edge - Google Patents

Abstract

A rigid element (S) of plastic plates is embedded into the lower sealing sheet overlapping part (KB) of an upper sealing sheet (OD) from its overlapping edge (UK). A sealing material is interposed between the overlapping parts of both sealing sheets (OD,UD). An independent claim is also included for a method for sealing overlapping part of upper and lower sealing sheets.

Description

waterproof sheeting are widely used in civil engineering and hydraulic engineering. Amongst other things they are used in landfill construction and in the sealing of basins and canals Commitment. Sealing membranes are usually membrane-like, flexible fabrics. They consist for example of plastics or bentonite. Next the perennial Connecting the individual sealing webs by welds is in a series of Applications for structural and economic reasons, an overlap sought without permanent connection. Also in these cases is the flow of the overlap area preferably to keep low. If possible is over here the overlap a ballast, which for example by a gravel pad or Concrete elements can be achieved arranged. This load overrides the overlap area and increased thus its sealing effect.

In some applications, such as the lining of open channels, is a cover of the Geomembranes with ballast material from technological or economic Not reasons possible. According to current knowledge, this is trying to be through the use one possible Great Sealing material between the underlying and the overlapping upper waterproofing membrane to achieve a good seal. With This method achieved sealing is subject to large fluctuations. The problem with these overlaps is usually too low contact pressure in the contact area of the overlap. The pressure reduction within the contact area is of the actually achieved dependent on local sealing effect, generally not theoretically exact and often due to of interdependence of contact pressure and sealing effect to be regarded as unstable.

The pressure joint described in the present specification ensures a high contact pressure in the region of the overlap, in particular in the contact region (KB). For this purpose, stiffness elements (S) are to be arranged in or on the overlapping, upper sealing sheet (OD) ( 1 ). These stiffness elements must be positively connected in the direction perpendicular to the plane of the geomembranes with the upper geomembrane. The stiffness elements must protrude sufficiently far beyond the region of the overlap, in particular over the contact region (KB), in the direction of the end of the upper sealing web (OD) facing away from the overlap.

In this pressure area (DB) acts on the upper sealing membrane (OD) thus also on the stiffness elements (S) with sufficiently permeable underground and suitable hydraulic boundary conditions of full water pressure. The stiffness elements (S) become reliable within this range pressed down and transfer this force effect over Lateral and momentary forces in the contact area (KB). Prerequisite for this are suitable support conditions, which ensure the pressure concentration within the contact area. This can be done, for example, by a comparison with the pressure range (DB) slightly increased execution of Contact area (KB) or the arrangement of an additional Sealing material (M) within the contact area (KB) achieved become. Due to the usually considerable water load and the power transmission in the contact area (KB) is one compared to previous approaches clearly improved sealing effect achieved. This could be done in experiments in a pressure vessel the research institute for Hydraulic engineering and water management of the Technical University of Munich impressively be occupied. The leachate losses were not even under ideal boundary conditions previous proposals for solutions significantly less than ten percent of the comparative measurements. Based on 1 m joint length in the direction of the overlapping edge (ÜK) showed at a pressure altitude Leakage water losses of significantly less than 80 ml per minute. Without the disturbing ones edge effects of the pressure vessel Significantly lower leachate losses are to be expected. For many hydraulic engineering applications, the pressure joint when properly executed as be considered technically tight.

In the contact area (KB) different sealing materials (M) can be arranged ( 2 ). A swelling or an increase in volume of the sealing material is not necessary. In principle, a largely tight connection between two sealing sheets without additional sealing material can be achieved with the pressure joint ( 1 ).

Of the under the overlap prevailing water pressure must be to ensure the sealing effect the pressure joint is much smaller than the water side of the overlap be attacking water pressure. The material below the overlap, or the subsoil, must be so permeable that by the Sealing water drainage system without significant backwater effects dissipated can be.

To improve the drainage effect in the pressure region (DB), a drainage material (E) can be arranged below the upper sealing membrane (OD). A comparatively high deformability of this material (E) can be the support conditions for the pressure joint, in particular the pressure concentration in the contact area (KB), improve.

Of particular importance is the deformability of the stiffness elements (S) in the direction of the overlapping edge (ÜK) or the joint. Good deformability is necessary in this direction in order to avoid mechanical constraints which would lead to local pressure shields in the pressure joint. This can be achieved, for example, by steel pin rows arranged in parallel in the geomembrane ( 4 ) or on the surface of the upper sealing sheet (OD) located plastic ribs ( 5 ) can be achieved. When using plate-like stiffness elements is to ensure the Querverformbarkeit on a small width of the individual plates.

The Stiffness elements can also later, especially directly on the construction site, frictionally with the geomembrane get connected. This can be especially true with regard to handling the Gasket web rolls of large Be an advantage. Within the geomembrane, for example, suitable Pockets or quiver-like Structures are arranged, in which subsequently the stiffness elements introduced become. these can secured for example by Velcro straps against slipping out become. The insertion of the stiffness elements can by a conical shaping of these elements are facilitated.

The Function of the stiffness elements can also be a special rigid geomembrane met become. Also in this case is on a sufficient deformability in the transverse direction. This can be done for example by vertical to the overlapping edge arranged shallow cuts in the surface of the upper geomembrane will be realized.

Existing protective rights relate, inter alia, to the superficial protection of geomembranes ( DE 43 08 341 A1 ) or on the mechanical reinforcement of plastic roofing membranes and geomembranes ( DE 43 34 306 A1 ). However, the deliberate integration of particularly rigid structures for pressure transmission is not described in any of these documents.

In a particularly simple variant of the pressure joint, the upper geomembrane is turned back down around the stiffness elements in such a way that the embossed end of the upper geomembrane extends underneath the stiffness elements over the entire contact region ( 6 ). The advantage of this method lies in the fact that the geomembranes do not have to be prepared for the use of the pressure joint. To simplify the assembly, simple mechanical auxiliary fixtures, which can be realized for example by Velcro fasteners, may be advantageous. The stiffness elements can also be prepared with regard to their positional stability. Thus, a plurality of bars can be connected by simple links to windable, mat-like structures, which are characterized by a high Querverformbarkeit and sufficient rigidity in the longitudinal direction.

In the direction perpendicular to the overlapping edge (ÜK) is the pressure range (DB) is typically equal to or longer than the contact area (KB). Typical lengths of pressure range and contact area are a few decimeters. Under special boundary conditions, in particular in difficult support conditions or very high pressure levels, too lengths from clearly above One meter will be appropriate.

Several embodiments The invention will be described below with reference to various drawings explained in more detail. she each show highly simplified representations.

DB

pressure range

e

drainage material

KB

contact area

M

Sealing material, sealing material

OD

Upper geomembrane

S

stiffness element

U

underground

UD

Lower geomembrane

W

water

Claims (14)

Device for sealing overlaps an upper sealing sheet (OD) and a lower sealing sheet (UD), with one or more stiffness elements (S), which with the upper sealing sheet (OD) are positively connected and both over the contact area (KB) as well as a sufficiently long pressure range (DB) in the from the overlap edge (ÜK) facing away Extend direction. Device according to claim 1, characterized in that that within the contact area (KB) between the upper geomembrane (OD) and the lower sealing sheet (UD) suitable sealing material (M) is arranged. Device according to Claim 1 or 2, characterized that the sealing material (M) either on the upper geomembrane (OD) or the lower waterproofing membrane (UD) is permanently attached. Device according to one of claims 1 to 3, characterized in that the stiffness elements (S) are arranged perpendicular to the overlapping edge (ÜK) Steel or plastic plates exist. Device according to one of claims 1 to 4, characterized that the stiffness element (S) by a particularly rigid design the upper sealing membrane (OD) in the pressure and contact area replaced becomes. Device according to one of claims 1 to 5, characterized that the stiffness elements (S) perpendicular to the overlapping edge (ÜK) a considerably higher Possess stiffness than towards this edge. Device according to claim 6, characterized that the stiffness elements (S) from perpendicular to the overlapping edge (ÜK) arranged rod-shaped steel or plastic elements. Device according to claim 6, characterized that the stiffness elements (S) from perpendicular to the overlapping edge (ÜK) arranged narrow Steel or plastic plates exist. Device according to claim 7 or 8, characterized that the stiffness elements (S) are mechanically detachable, in particular in quiver-like or pocket-like structures, connected to the upper geomembrane (OD) are. Device according to claim 6, characterized that the stiffness elements (S) by one in the direction of the overlapping edge (ÜK) wavy structure the surface the upper geomembrane (OD) or through perpendicular to the direction the overlap edge (ÜK) the upper sealing sheet (OD) arranged rib-like reinforcements be replaced. Device according to one of claims 1 to 9, characterized in that a particularly permeable material (E) is arranged in the pressure region (DB) becomes. Device according to claim 10, characterized that in the pressure region (DB) arranged particularly permeable material (E) has a lower rigidity than the adjacent elements the construction and the underground. Method for sealing an overlap of an upper geomembrane (OD) and a lower geomembrane (UD), characterized in that that the water pressure which is within a long enough Pressure range (DB) outside the area of the overlap on non-positive with the upper sealing sheet (OD) connected stiffness elements acts, of these in the contact area with the lower geomembrane (UD) transmitted and thereby the sealing effect of the overlap is improved. Method according to claim 13, characterized that the upper sealing sheet (OD) so around the stiffness elements (S) pushed back down that will be beaten back End of this path under the stiffness elements (S) over the entire contact area (KB).