Spillway liner and method

Abstract

A liner is formed in an excavated spillway by providing a plurality of rectangular flexible liner sections with each liner section having a parallel series of elongated continuous and adjacent tubular pockets pre-filled with a dry cementitious material or a fine granular material. The liner sections are provided with a surrounding generally flat perimeter boarder. The liner sections are laid into the spillway with their boarders overlapping and the boarders are secured together with the tubular pockets aligned in the same direction to form a continuous liner blanketing the spillway. The tubular pockets are arranged in the spillway with their elongated sides presented to the expected direction of water flow in the spillway. The liner sections may be anchored to the spillway with anchor pins.

Description

FIELD OF THE INVENTION

The present invention relates generally to erosion control and more specifically to a method of lining spillways and ditches.

BACKGROUND OF THE INVENTION

Two current methods of lining spillways are placing stone in the spillway trench or pouring a concrete trench liner. Placing stone in the spillway can take days and requires several different pieces of equipment, which allows a window of time for erosion of the spillway during placement of the stone. Pouring cement from the mixing truck requires not only transporting cement, but also a considerable amount of water in the mix. If the cement must be pumped, then both a mixing and a pumping truck are required.

As increasing emphasis is exerted on erosion control and the cost of the current methods of placing stone in the spillway or lining the spillway with poured concrete are expensive. It is accordingly an object of the present invention to provide a method for forming a spillway liner which can be deployed quickly and at a reduced cost compared to the present methods of placing stone in the spillway or pumping concrete.

SUMMARY OF THE INVENTION

The spillway liner of the present invention is formed by providing a plurality of rectangular (4 sided, including square) flexible liner sections, each having a parallel series of elongated continuous and adjacent tubular pockets containing a dry cementitious material or a fine granular material, and having a surrounding generally flat perimeter boarder. A plurality of the liner sections are laid in the spillway with their boarders overlapping. The overlapping boarders are secured together with the tubular pockets aligned in the same direction to form a continuous liner blanketing the spillway. The tubular pockets are arranged in the spillway with their elongated sides presented to the expected direction of water flow in the spillway. Presenting the filled pockets generally perpendicular to the fluid flow creates an energy dissipating effect.

When the tubular pockets are pre-filled with a dry cementitious material, such as a rapid setting cement, the upper sheet surface of the liner sections are constructed of a water permeable material so that after the liner sections have been laid, they are saturated with water in order to cure the cementitious material. The bottom sheet of the liner sections in this instance are made of a sheet material which is non-permeable to water.

The overlapping boarders are provided with aligned grommets for securing the liner sections to the spillway with anchor pins. The overlapping boarders of the liner sections may also be secured together with hook and loop fasteners.

The pre-filled liner system of the present invention can be deployed quickly and at a reduced cost compared to the present methods of placing stone in the spillway or pumping concrete.

The spillway liner sections are pre-filled with rapid setting cement or fine ground aggregate before transporting them to the work site. Pre-filling of the liner sections in an assembly line generates cost savings and less waste of the filling material. The liner sections may be filled by different methods. One method is to hang the liner sections and allow the dry filler material to be gravity fed into the individual pockets of the section to be filled from a silo or from a screw feed. Alternatively, cement can be blown into the pockets while the liner section is in a horizontal or vertical position. The filled liner sections can vary in length and width to accommodate different site requirements, and the liner sections can be delivered to the work site on reels or lying flat on pallets.

BRIEF DESCRIPTION OF THE DRAWINGS

Other objects and advantages appear hereinafter in the following description and claims. The accompanying drawings show, for the purpose of exemplification, without limiting the scope of the invention or appended claims, certain practical embodiments of the present invention wherein:

FIG. 1 is a schematic plan view of a single liner section for incorporation into the spillway liner of the present invention;

FIG. 2A is a schematic end view of the liner section of FIG. 1 with the pockets unfilled as seen along section line A-A;

FIG'S. 2B and 2C are schematic end views of the spillway liner section as shown along section line A-A of FIG. 1 with the pockets filled but prior to closure of the end to close the pockets in FIG. 2B and after closure of the end in FIG. 2C;

FIG. 3 is a schematic plan view of two spillway liner sections having overlapping boarders secured together illustrating the combining of liner sections to form the spillway liner of the present invention;

FIG. 4 is an end view of a liner section for the spillway liner of the present invention illustrating an embodiment wherein the top layer sheet is water permeable and the water layer sheet comprising the liner section is water impermeable; and

FIG. 5 is a perspective view illustrating the spillway liner of the present invention as deployed in a spillway.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring to the drawings, the spillway liner 10 of the present invention (see FIGS. 3 and 5) is comprised of a plurality of rectangular flexible liner sections 11. Each liner section 11 is provided with a parallel series of elongated continuous and adjacent tubular pockets 12 which contain a dry cementitious material or a fine granular material designated as 13 in FIG. 2B. Each liner section 11 is surrounded by a generally flat perimeter boarder 14.

The spillway liner 10 is constructed in the spillway 15, which is excavated in the underlying earth 16 (see FIG. 5), by laying a plurality of the liner sections 11 in the spillway 15 with their boarders overlapping. The overlapping boarders 11 are preferably secured together by placing weights or rocks thereon or by hook and loop securement strips (not shown). The tubular pockets 12 of each liner section 11 are all aligned in the same direction to form a continuous liner 10 blanketing the spillway 15 as shown in FIG. 5. The tubular pockets 12 are arranged in the spillway 15 with their elongated sides 17 presented to the expected direction of water flow as indicated by arrows 18 in FIG. 5 in the spillway 15. The liner sections 11 are deployed into spillway 15 from the bottom 20 to the top 21 allowing overlap of the top or upper liner section 11 over the lower liner section 11 in similar fashion to shingles being laid upon a roof to thereby prevent water from going under the liner sections 11.

The overlying boarders 14 have aligned grommets 22 for securing the liner sections to the spillway 15 with T-head anchor pins 19 (FIG. 3).

Each liner section 11 is constructed of an upper flexible sheet 24 and a bottom flexible sheet 25 forming pockets 12 therebetween. See in particular FIG. 2B. The series of elongated pockets 12 are either formed by providing flexible partitions 26 therebetween or by simply directly stitching upper sheet 24 to lower sheet 25 as illustrating in FIG. 2C.

The elongated pockets 12 are fillable from end 30 of liner sections 11. Upper sheets 24 and lower sheets 25 are separable at end 30 to provide access to the interior of the individual pockets 12 for filling. After filling of the pockets 12 with a cementitious or fine granular material, the pockets 12 are closed off by closing the open end 30 which is sealed together with hook and loop securement strips or sewn together at the edge 32.

The spillway liner sections 11 are preferably pre-filled with rapid setting cement or fine ground aggregate 13 before deploying the sections to the work site. Liner sections 11 may be filled by any number of different methods. One suggested method is to hang the liner section 11 with one end 30 or 31 positioned at the top and allow the dry cement to be gravity fed into the individual pockets 12 for filling from a silo or a screw feed. Alternatively, the dry cement can be blown into the pockets while the liner section is in a horizontal or vertical orientation.

With particular reference to FIGS. 2B and 2C, the upper sheet 24 at the bottom sheet 25, are usually constructed of a water permeable fabric when the filler material 13 is selected as a fine aggregate.

FIG. 4 illustrates a liner section 11 of the present invention with the pockets 12 formed into a slightly different shape or configuration. In this embodiment, the pockets 12 are filled with a dry fast setting cement and the pocket shapes are given a slightly different configuration from that illustrated in the other figures to illustrate a possible variation. In addition, since the pockets 12 are filled with a dry fast setting cement, the upper sheet 24 is a UV resistant water permeable fabric and the lower sheet 24 is a plastic sheet or a plastic impregnated fabric which is non-permeable to water. Accordingly, once the liner sections 11 are deployed, water is sprayed on the top sheets 24 of the liner sections blanketing the spillway 15 in order to allow the cement to begin curing. Alternatively the liner section may be submerged in fluid just prior to being laid. The result is that within a few hours of spraying water on the laid spillway liner 10, the spillway is capable of handling water flow. Also, the thickness of the liner sections 11 may be varied in order to change the resistance of the completed spillway liner 10 to water flow and to also accommodate greater flow in the spillway.

Claims

1. A method of forming a spillway liner comprising: providing a plurality of rectangular flexible liner sections, each having a parallel series of elongated continuous and adjacent tubular pockets containing a dry cementitious material or a fine granular material and having a surrounding generally flat perimeter border;laying a plurality of said liner sections in a spillway with said borders thereof overlapping and securing said borders together with said tubular pockets aligned in the same direction to form a continuous liner blanketing at least a portion of said spillway;said tubular pockets arranged in the spillway with their elongated sides presented to the expected direction of water flow in said spillway.

2. The method of claim 1, said liner sections provided with an upper sheet surface which is water permeable, and filling said tubular pockets with dry cementitious material and saturating said liner sections with water after being laid to cure said cementitious material.

3. The method of claim 1, securing said liner sections to the spillway with anchor pins.

4. A spillway liner for erosion control in spillways and ditches, comprising: a plurality of rectangular flexible liner sections, each having a parallel series of elongated continuous and adjacent tubular pockets and a surrounding generally flat perimeter border;said pockets having closable access fill openings along one edge of each liner section;said pockets filled with dry cementitious material or fine granular material;said liner sections arranged in a spillway with adjacent of said borders overlapping and secured together with said tubular pockets aligned in the same direction to form a continuous liner blanketing at least a portion of said spillway with the elongated sides of said filled pockets presented to the expected direction of water flow in said spillway.

5. The spillway liner of claim 4, said liner sections having an upper water permeable sheet and said pockets filled with cementitious material.

6. The spillway liner of claim 5, said liner sections having a bottom sheet which is non-permeable to water.

7. The spillway liner of claim 4, said overlapping borders having aligned grommets for securing the liner sections to said spillway with anchor pins.

8. The spillway liner of claim 4, said overlapping borders secured together with hook and loop fasteners.