Patent Application
20250027286
This application is directed to stabilized drainage layer systems that can be adapted for erosion prevention. Applications include, but are not limited to, revetment and erosion prevention systems including a layer of stabilized aggregate material.
Stabilized drainage layers and similar erosion prevention systems can be used to help prevent, reduce or mitigate soil erosion from areas susceptible to water flow. Traditionally, revetment systems have been used to help stabilize the drainage layer, for example in the form of a revetment mat, retaining wall or landscaping system formed of stone, masonry or concrete revetment blocks.
U.S. Pat. No. 6,579,038 B1 to McAllister et al. and assigned to Applicant describes a revetment block system in the form of an articulating revetment mat with a combination of standard blocks and end blocks. The blocks have four sidewalls, each with a vertical portion and a tapered portion, and can be formed of precast concrete or other suitable material. The blocks are formed with a number of interlocking projections and recesses, and a combination of apertures, or openings configured for plant growth and foliage.
A dome structure can be provided on the revetment blocks to help dissipate kinetic energy, reduce shear forces, and encourage settling of particulate matter to help further reduce erosion. A pair of openings can extend from an upper surface or plateau portion of each block to a lower surface of the block. The blocks can be interlocked via cabling extending through a series of ducts defined through the parallel sides, and configured for interlocking the adjacent rows of the revetment mat together. The end blocks have a larger form factor than the standard blocks, providing the mat with evenly aligned edges and improved resistance to upward lift and turning, as compared to using half-blocks in the end locations.
U.S. Pat. No. 6,866,446 B2, also to McAllister et al. and assigned to Applicant, describes a revetment block system where the sidewalls have a first lower vertical surface, first and second upper vertical surfaces, and transitions between the upper and lower surfaces. The sidewalls define interlocking features that extend outward, normal to the upper vertical surfaces, or at an angle. The sidewalls also define corner spaces for communicating with the interlocking features; e.g., extending upward and outward from the first lower vertical surface toward the second. The revetment blocks can also include dome structures, ducts for cabling, and apertures for plant growth and foliage.
U.S. Publication No. 2023/0010848 A1 to Karau et al. and assigned to Applicant describes a revetment block system with top and bottom surfaces and generally parallel, opposing first and second sidewalls, along with a horizontal duct for cabling. The top surface has a non-parallel relationship with respect to the bottom surface, and includes a leveling pad adjacent the first sidewall. The leveling pad is configured so that the horizontal ducts of stacked revetment blocks are parallel.
An erosion prevention system includes a geotextile material applied over a top layer of soil, and a layer of aggregate material applied over the geotextile material. At least some of a top portion of the layer of aggregate is bound together using a binder material (e.g., a polymer binder or polymer resin material) that can be applied during or after installation of the aggregate material, for example by spraying, pouring or flooding. The binder can include an aromatic resin, aliphatic resin or other polymer resin, urethane, polyurethane, per-polymer or pre-polymer (prepolymer) material, or a combination of such materials, as described herein, and as known in the art. The top portion of aggregate that is bound by the binder material extends to a selected depth in the aggregate layer, for example up to two inches (about five centimeters) or more, as measured from the top surface.
A layer of revetment blocks can be installed over the layer of aggregate. The revetment blocks may have a common height along all the sides, domed structures for flow direction, or tapered top surfaces. A method of installing the system is also provided.
Certain details are set forth below to provide a sufficient understanding of various examples and embodiments of the disclosure. It will be clear to one skilled in the art that these examples and embodiments can be practiced with different combinations of the elements that are disclosed in the drawings, and with or without all the particular details that are described in the specification.
This application describes erosion prevention systems and methods to stabilize a drainage layer, for example a drainage layer with aggregate disposed over an underlying layer of earth or soil. A layer of geotextile can be disposed between the aggregate and the soil, and a layer of revetment blocks or a revetment mat can be disposed over the aggregate to help reduce or mitigate erosion. The aggregate can be stabilized with a binder to help inhibit erosion in areas of water flow, for instance along rivers, streams, shorelines, spillways, overflow channels or drainage channels, or at boat ramps and other access points, and in other locations susceptible to surface or groundwater flow.
In some applications, a revetment mat formed of articulated revetment blocks can be disposed over the aggregate. Suitable revetment blocks can be manufactured of materials like concrete and interlocked together to form an erosion prevention system conforming to the specific hydraulic performance characteristics required in a particular location. The revetment blocks can also be formed with substantially flat, generally parallel top and bottom surfaces, domed structures, or a tapered top surface that is not necessarily parallel to the bottom. A suitable layer of revetment blocks can also be formed from interlocking blocks that are coupled together with cables, in order to hold the blocks in place. Adjacent rows and columns of the revetment blocks can also be coupled together with cables, for great system stability.
A method for installing the system can include preparing the drainage layer by grading the top layer of soil to a desired slope or grade, and then installing a geotextile material over the top layer of soil. The geotextile material can be configured to help prevent erosion or washout of the underlying soil, while allowing for water flow. In some examples, the geotextile material can also allow for vegetation to grow through the material.
A layer of aggregate material can be deposited over the geotextile material. In some examples, the layer of aggregate material can have a depth of about 4 inches (about 10 cm) or less, or up to about 6 inches (about 15 cm) or more. For example, the layer of aggregate may have a depth of at least 2 inches (or about 5 cm) up to 12 inches (about 390 cm), or up to 24 inches (about 60 cm), or more.
The aggregate material can include relatively coarse rocks/stones of various shapes and sizes; e.g., from about 0.09-0.10 inches (about 0.2 to.25 cm) or less, up to 2 inches (about 5 cm) or more. In some examples, the aggregate material may generally include rocks, stones or other material with sizes ranging from about 0.75 inches (or about 2 cm) up to about 1.5 inches (or about 4 cm) The aggregate material can be stabilized with a polymer resin or other suitable binder material selected to bind the aggregate together, while maintaining porosity, permeability and void ratio to allow for drainage and helping reduce movement or migration of the aggregate and geotextile, to further prevent erosion of the underlying layer of soil.
The revetment blocks or mat can be installed over the aggregate material. The blocks can be formed using a concrete material, for example a precast concrete material, or a suitable masonry material. The revetment blocks can be configured with a smooth top surface to facilitate runoff and drainage, while holding the underlying layers of aggregate and other materials in place.
Under certain flow conditions, the aggregate material or soil may shift or migrate under the revetment blocks or revetment mat, which can degrade performance of the erosion protection system. To reduce the migration or erosion of the aggregate material and underlying soil, a binder material can be applied to the aggregate layer. Suitable binders can be selected for binding at least an upper portion of the aggregate material together, while maintaining porosity, void ratio and permeability in order to preserve performance of the drainage layer, while reducing or minimizing migration and erosion.
Depending on application, suitable binder materials can include aromatic resins, aliphatic resins or other polymer resin materials, urethane, polyurethane, per-polymer or prepolymer materials, or any combination or derivative thereof, as described herein, and known in the art. In some examples, the binder can be sprayed, poured or flooded over the installed layer of aggregate material, or mixed with the aggregate material, as described herein, and as known in the art. In some examples, the binder can include one or more polymer or polymer resin materials applied to penetrate the layer of aggregate material to a given depth, so that the top layer of the aggregate material is bound together.
For example, the binder can be applied to penetrate, bind and stabilize the top layer of aggregate material to a depth of at least 2 inches (about 5 cm), as defined from the upper surface of the aggregate. In some examples, the binder can be applied to penetrate and bind the layer of aggregate material to a depth of at least 3 inches (about 7 or 8 cm) from the upper surface. In other applications, the binder can be poured onto or flooded over the surface of the aggregate material to allow for deeper penetration; e.g., up to 6 inches (about 15 cm) or more, while retaining drainage properties for water flow.
Alternatively, the binder can be mixed or premixed with the aggregate material, or with a portion of the aggregate material. The mixed binder and aggregate can then be applied to the desired thickness or depth, for example over an unmixed layer of aggregate (without binder), or directly onto a geotextile layer.
The combination of aggregate and binder can also be controlled so that the stabilized layer remains substantially permeable to water flow, without creating a non-porous layer or other substantially non-porous or solid (impervious) barrier. The aggregate and binder can be selected to maintain porosity and void ratio, for example up to 90-95% or higher, so that the volumetric flow rate is substantially the same or similar to that of the unbound aggregate.
An erosion protection system that includes a polymer resin or other binder material applied over the aggregate layer, as described here, can stabilize the drainage layer by preventing migration of the aggregate. The system can thus prevent erosion of the underlying soil and maintain stability of the drainage layer while reducing the tendency for degradation of the system over time, improving service life while reducing or minimizing the risk of failure.
These benefits are exemplary, and do not limit the scope of the claims except as expressly recited therein. The erosion prevention system also has other advantages, as described herein, and as understood by a person of skill having reviewed the specification, drawings and claims.
As shown in
The combination of aggregate 135 and binder 145 in layer 140 produces a bound complex, stabilizing the aggregate layer 130 over the geotextile 120 and soil layer 110. A revetment block layer 150 can also be included; e.g., a layer 150 of revetment blocks 155 disposed over aggregate layer 130, on top of the stabilized layer 140.
The binder 145 can be applied to penetrate the aggregate 135 to a selected depth d, measured from the top surface of aggregate layer 130. Depending on application, the depth of the stabilized layer 140 can be defined as a fraction of the total depth of the aggregate layer 130, disposed over the geotextile 120. For example, the stabilized layer depth d can be about one tenth, one fifth, one sixth, or one fourth of the total aggregate layer depth D, or up to one third or one half of the aggregate layer depth D. In these examples, an “unbound” region 146 of aggregate layer 130 may extend between the bottom of the stabilized layer 140 and the geotextile 120. The binder 145 does not substantially penetrate into this unbound region 146, and the aggregate 135 is not combined with binder 145 in this region.
The stabilized layer depth d can also extend over more than half of the aggregate layer depth D, or to substantially the entire depth D of the aggregate layer 130. For example, the binder 145 can penetrate more than half or substantially all of the aggregate layer 130, down to the geotextile 120. In some of these applications, substantially all of the aggregate 135 is bound together with binder 145, and the stabilized layer depth d and aggregate layer depth D are substantially the same.
The binder 145 can also selectively applied to aggregate layer 130 in order to maintain water permeability and drainage properties through the stabilized layer 140, and into the lower (unbound) region 146 of aggregate 135, extending down to the geotextile 120 disposed over soil layer 110. At the same time, binder 145 binds the aggregate 135 together in the stabilized layer 140, reducing migration or movement of the aggregate 135 in both stabilized layer 140 and in the lower unbound region 146, in order to help prevent erosion of the underlying earth or soil 115 in soil layer 110.
A layer 150 of revetment blocks 155 can be installed over the aggregate layer 130, on top of the stabilized layer 140. Revetment blocks 155 can be configured to direct water flow over the aggregate layer 130, further stabilizing system 100 by reducing migration or movement of the aggregate 135 in both stabilized layer 140 and unbound region 146, above the geotextile 120, and further reducing erosion of soil layer 110, below the geotextile 120.
As illustrated in the section view of
A layer 150 of revetment blocks 155 can also be disposed over the aggregate layer 130. Each of these layers 120, 130, 140 and 150 can be formed from a range of suitable materials, described in turn.
As shown in
The aggregate layer 130 is deposited over the geotextile material 120. The aggregate 135 making up the aggregate layer 130 can include relatively coarse rocks/stones of various shapes and sizes; e.g., from about 0.09-0.10 inches (about 0.2 cm) or less to about 2 inches (about 5 cm) or more. In particular examples, the aggregate material can include average material sizes with mean (D50), median or average particle sizes ranging from about 0.75 inches (or about 2 cm) or less to about 1.5 inches (or about 4 cm) or more.
The layer 130 of aggregate 135 provides a relatively porous structure that allows for water flow and drainage, while also helping to prevent erosion of the underlying earth or soil 115 in soil layer 110. In some examples, the aggregate 135 in layer 130 can have a depth D of 4 to 6 inches (or about 10 to 15 cm). In some examples, the aggregate layer 130 can have a depth of at least 2 inches (or about 5 cm) up to about 12 to 24 inches (about 30-60 cm), or more.
In some examples a layer 150 of revetment blocks 155 can be installed over the layer 130 of aggregate 135; e.g., forming a revetment mat or similar revetment structure to direct water flow F along system 100. Suitable revetment blocks 155 can be formed using durable materials such as concrete (e.g., precast concrete), or a composite masonry material. The individual blocks 155 can be provided with interlocking features to improve structural performance, and one or more dome structures 160 extending from the upper surface 162, generally parallel to the lower, bottom surface 164.
Suitable revetment blocks 155 can be provided in an untapered configuration, with a common thickness, depth or height H defined between the top and bottom (or upper and lower) surfaces 162, 164, along each of the respective sides. The individual blocks 155 can be further configured with smooth domed structures 160 and upper surfaces 162 to facilitate runoff and drainage, while holding the layer 130 of aggregate 135 in place over the geotextile 120 and underlying soil layer 110. Blocks 155 can also include one or more apertures configured for plant growth or foliage, and to relieve hydraulic pressure.
Additional openings, ducts or channels can be provided for coupling blocks 155 together; e.g., using cables or cabling 170. In some applications the blocks 155 can be coupled together to form the revetment block layer 150 as one or more revetment mat structures, which can be installed over the aggregate layer 130 as a unit, or in modular form.
Erosion prevention systems 100 can be used in or along flow channels, levees, shorelines, bridge abutments, downchutes, pipe outlets, dams, spillways, weirs, boat ramps, basins, retention ponds, low water crossings, ditches, slopes, and other environmental applications subject to water flow. Under certain flow conditions, notwithstanding the additional erosion reduction provided by the upper layer 150 of revetment blocks 155, some material in the layer 130 of aggregate 135 may shift, erode or migrate over time. If this issue is not addressed, it can ultimately lead to degradation or failure of the erosion protection system 100.
To address this problem and further reduce erosion, a polymer resin or other suitable binder material 145 can be applied to aggregate layer 130; e.g., after installation of the aggregate 135 over the geotextile 120. The material of binder 145 can be selected from stable, non-toxic, environmentally suitable organic polymers, copolymers, prepolymers, urethanes and polyurethanes, or any combination or derivative thereof, as described herein, and known in the art. The binder 145 can be applied over the top surface of the aggregate layer 130, so that the binder 145 penetrates the aggregate 135 to a selected depth d, forming a stabilized layer 140 of aggregate 135 mixed with binder 145.
The binder 145 can be selected and applied to the aggregate layer 130 to have the effect of binding at least an upper portion of the aggregate 135 to form a stabilized layer 140 of aggregate 135 that is bound together with binder 145, as defined along the top portion of the aggregate layer 130. The stabilized layer 140 of aggregate 135 combined with binder 145 can reduce or minimize erosion of the aggregate 135, not only in stabilized layer 140 but also in the unbound region 146 between stabilized layer 140 and geotextile 120, above soil layer 110.
In some examples, the binder 145 can be applied by spraying onto the top surface of the aggregate layer 130, or by other suitable application technique. The binder 145 penetrates the top surface of the aggregate layer 130, binding the aggregate 135 together to form a stabilized layer 140 extending to a depth d of (e.g.) at least 2 inches (about 5 cm), as defined from the top surface of aggregate layer 130. In some examples, the stabilized layer 140 extends to a depth d of at least 3 or four inches (or about 7-10 cm), or more, where the depth d is measured from the upper surface of aggregate layer 130, as shown in
In other examples, the binder 145 can be mixed with aggregate 135 before application, or poured onto or flooded over the top surface of the aggregate 135 to provide for deeper penetration into the aggregate layer 130. The binder concentration can also be controlled to maintain drainage and water permeability through the stabilized layer 140 and into the unbound region 146 of aggregate 135, avoiding formation of a substantially non-porous or relatively non-permeable (solid) barrier to water flow.
The stabilized layer 140 stabilizes aggregate layer 130, helping to prevent migration or movement of aggregate 135 in both stabilized layer 140 and in the unbound region 146, below stabilized layer 140. The multi-layered configuration of system 100 can also help prevent erosion or degradation of the underlying earth or soil 115 in soil layer 110, below geotextile 120, increasing the service life of system 100 while reducing the risk of partial or substantial failure.
Revetment blocks 155 can formed of durable materials such as precast concrete and composite masonry materials, and adapted to direct water flow F in a stabilized drainage layer implementation of system 100. Apertures can be provided in the individual blocks 155 for vegetation and plant growth, and to relieve hydraulic pressure, as described above. In this particular example, the blocks 155 can be provided in a tapered or overlapping form, in one or more overlapping or offset rows or revetment mat structures tied together with cabling 170.
As shown in
The tapered configuration of revetment blocks 155 can help dissipate kinetic energy in the water flow, and create a shingling effect to direct flow over or along the upper surfaces 162 of the adjacent blocks 155. An erosion prevention system 100 with a layer 150 of tapered revetment blocks 155 can be used, for example, in channels, levees, shorelines, bridge abutments, downchutes, pipe outlets, dams, spillways, weirs, boat ramps, basins, retention ponds, low water crossings, ditches, slopes, or other environment application subject to water flow, as described above for system 100 of
The stabilized layer 140 can be formed by applying binder 145 onto or over the aggregate layer 130. The binder 145 can be applied to penetrate a top portion of the aggregate 135, forming the stabilized layer 140 of mixed aggregate 135 and binder 145. The binder 145 combines with the aggregate 135 to stabilize aggregate layer 130, helping prevent erosion and migration of aggregate 135 in both stabilized layer 140 and in the unbound region 146, between stabilized layer 140 and geotextile 120. Stabilized layer 140 can also help prevent erosion of the underlying earth or soil 115 in soil layer 110, below geotextile 120, reducing the rate of degradation in system 100 over time, and increasing service life while lowering the risk of partial or substantial failure.
Taken together,
Suitable erosion protections systems 100 can also include common elements, or a combination of different elements according to
The binder 145 can be applied to any suitable depth d in aggregate layer 130, leaving an unbound region 146 between stabilized layer 140 and geotextile 120, or substantially all of the aggregate 135 can be mixed with binder 145, so that the stabilized layer depth d is substantially the same as the total depth D of aggregate 135. The earth or soil 115 in the underlying soil layer 110 can also be graded to any selected slope S, with a layer of geotextile material 120 disposed between the soil layer 110 and aggregate layer 130, or the geotextile material 120 may be absent, depending on the slope S and rate of flow F, the condition of soil layer 110, and other environmental considerations.
As illustrated in
In some examples, the layer of aggregate material can be installed over the geotextile material to a total depth of at least 2 inches (or about 5 cm), or to a total depth of at least 6 inches (about 15 cm), or to a depth in the range of 12 to 24 inches (30-60 cm) or more. In some examples, the geotextile material may be absent, and the aggregate can be disposed directly onto or adjacent the top surface of the underlying soil layer.
The method 200 can include applying a polymer resin or other suitable binder material onto or over the layer of aggregate material, for example to create a stabilized layer 140 of aggregate 135 that is mixed with binder 145, as described herein (step 230). For example, the binder can be sprayed over the top surface of the aggregate layer, or the binder can be mixed with the aggregate or poured or flooded over the top surface to penetrate the aggregate layer to a selected depth, as described herein, so that at least some of the aggregate material in a top portion of the aggregate layer is bound together with the binder (step 235).
Applying the binder can be performed after installation of the aggregate layer, or contemporaneously. For example, the binder can be sprayed or flooded onto the top surface of the aggregate layer after the aggregate has been applied to a desired depth and slope. The aggregate and binder can also be applied in sequence to selected regions of the system, or the binder can be premixed with some or all of the aggregate.
The binder material can include aromatic resins, aliphatic resins and other organic polymer or polymer resin materials, urethanes, polyurethanes, per-polymers or prepolymers, or a combination or derivative thereof, as known in the art, and as described herein. The binder can be applied to penetrate the aggregate to a depth of at least 2 inches (about 5 cm), as measured from the top surface of the aggregate layer. The binder can also be applied to depth of up to 2 to 4 inches (or about 5-10 cm), or to a depth of up to six inches (about 15 cm) or more.
Depending on application, method 200 can also include installing a layer of revetment blocks over the layer of aggregate material; e.g., a layer 150 of revetment blocks 155, as described herein (step 240). At least some of the blocks may have domed structures or an untapered profile with a common, substantially uniform height or thickness along each of the sides, for example according to
This description is provided to enable a person skilled in the art to make or use the disclosed examples and embodiments. Various modifications can be made, as apparent to those of skill in the art, and the techniques described here can be applied to other erosion protection systems, and under other environmental condition, without departing from the scope of the disclosure. The invention is thus not limited to the particular examples and embodiments that are shown and described, and also encompasses all of embodiments falling within the language of the appended claims, except as expressly recited therein.
This application claim priority to U.S. Provisional Patent Application No. 63/527,880, filed Jul. 20, 2023, “Stabilized Drainage Layer for Erosion Prevention System,” which is incorporated by reference herein, in the entirety and for all purposes.
| Number | Date | Country | |
|---|---|---|---|
| 63527880 | Jul 2023 | US |
