HK1080523B - Revetment block and mat - Google Patents

Description

Revetment block and mat

Technical Field

The present invention relates generally to a revetment block. More particularly, the present invention relates to a revetment block for use along the perimeter of a revetment mat and which is sized to eliminate the use of half sized revetment blocks which would raise the edge of the revetment mat as water flows over them. Further, the revetment mat is used to apply the above revetment blocks along its perimeter, thereby preventing upward jacking forces from acting on the mat from the perimeter.

Background

Revetment mats are used, for example, to protect soil along shorelines, spillways, drainage channels, ramps, etc. from the elements of flowing water. Current revetment mats are formed of joined concrete blocks that interlock together and follow specific hydraulic characteristics.

In us patent 4370075 to Scales, fig. 3 shows the common features of revetment mats. For example, the blocks of the top row are offset and not aligned with the blocks of the immediately lower row to form an aligned column. This offset alignment of rows is referred to as a "running bond" and is preferred because the blocks interlock so that each block contacts a greater number of blocks to form a more stable structure. However, since the edges of the revetment mat are not uniform, as best shown in fig. 3 and 5, half-size blocks must be added at the ends of alternating rows of revetment mats to align the ends of the rows uniformly. There are several problems associated with half-sized blocks. First, the half-size blocks have a smaller contact edge or surface than the blocks inside the edges of the pad. Second, half-size blocks are in contact with fewer blocks. These problems lead to the third problem of half-size block movement. Because of their smaller size and reduced contact with adjacent blocks, half-sized blocks will lift and rotate due to upward water thrust. Since the rope links extend transverse to the rows of mats, the raising of the half-size blocks will cause the edges of the revetment mat to bend. This is highly undesirable.

In view of the deficiencies of known revetment blocks, it is apparent that there is a need for a revetment block for a revetment mat that is sized to provide uniform alignment of rows of revetment mat, has improved hydraulic characteristics, and prevents the revetment block from rising.

Disclosure of Invention

It is an object of the present invention to provide a revetment block having dimensions such that when used in a revetment mat, a uniform revetment mat edge is formed.

It is a further object of the present invention to provide a revetment block sized to prevent upward hydraulic thrust.

It is a further object of the present invention to provide a revetment block for forming a revetment mat and preventing edge curling of a revetment mat.

It is a further object of the present invention to provide a revetment block having at least one dome which slows the velocity of water flowing over a revetment mat.

It is a further object of the present invention to provide a revetment block having a plurality of apertures therein for plant growth.

It is a further object of the present invention to provide a revetment block having tapered sidewalls.

A revetment block comprising a substantially rectangular block having two U-shaped vertical notches along each of first and second sides, a third side having a pair of U-shaped notches and three projections, and a fourth side having three U-shaped notches opposite the three projections of the third side and a pair of projections opposite the notches of the third side. The revetment block has a top surface and a bottom surface, the top surface having a dome surrounding first and second tapered wall openings. The third and fourth openings extend from the top surface to the bottom surface of the block. The first and second tapered wall openings extend vertically through the dome down to the bottom surface of the block. The second side has a half dome surrounding a pair of tapered U-shaped notches. The dome and the half dome are formed by curved walls extending from the top surface to the flat upper platform. Preferably, the first, second, third and fourth openings are substantially rectangular. The U-shaped notches of the first and second sides each form one half of an opening.

The revetment block further comprises at least one conduit extending through said revetment block, preferably from one recess to an opposite projection. The at least one conduit extends longitudinally between the third and fourth sides.

The first and second openings are vertically tapered from a wider upper portion toward a narrower lower portion. The U-shaped recess of the second side is tapered. The first, third and fourth sides taper proximate a top surface of the revetment block.

All the above objects are to be understood as examples only and further objects of the invention will be apparent from the description herein. Accordingly, the foregoing non-limiting description of the objects should be understood without further reading of the entire specification, claims and drawings.

Drawings

The aspects and advantages of the invention will become better understood with regard to the following detailed description of a preferred embodiment when considered in conjunction with the accompanying drawings, wherein:

FIG. 1 shows a perspective view of a right hand half-size revetment block of the present invention;

FIG. 2 shows a top view of the right hand half-size revetment block of FIG. 1;

FIG. 3 shows a side view of a right hand half-size revetment block taken along line 3-3 of FIG. 2;

FIG. 4 shows a top view of the revetment mat of the present invention;

FIG. 5 shows a perspective view of a left hand half-sized revetment block of the present invention;

FIG. 6 shows a top view of the left hand block half-size revetment block of FIG. 5;

FIG. 7 shows a side view of the left hand half-sized revetment block along line 3-3 of FIG. 6;

FIG. 8 illustrates a revetment mat using half size revetment mat end blocks;

FIG. 9 shows a plan view of the cords, sleeves and spacers used in the revetment mat of the present invention; and

figure 10 shows a top view of a revetment mat formed from a right hand and left hand block of half-size revetment blocks of figures 1 and 5.

Detailed Description

Bank protection block

The invention will now be described with reference to the drawings, and with reference first to fig. 1, a revetment block 10 is shown having a "block and a half" size and right hand design. The one-half design is shown as either right-hand or left-hand because it will be disposed either right or left of the row of revetment mats.

According to a first embodiment of the invention, the revetment block 10 is formed of precast concrete. The revetment block 10 has a substantially planar upper or top surface 12 and a bottom or lower surface 15 and has a plurality of sides extending between the upper and bottom surfaces 12, 15: a first side 24a, a second side 24b, a third side 25a and a fourth side 25 b. The revetment block 10 is typically substantially rectangular but may have any other suitable shape. The height of the block 10 may vary depending on the application and the appropriate hydraulic characteristics, but is typically between 70 and 240 millimeters. The height of the block 10 may be increased as more hydraulic force is involved.

As shown in fig. 3 and 4, the bottom or lower surface 15 of the revetment block 10 may preferably be substantially flat or planar for substantially continuous contact with the substrate soil 210 or filter media 200, which filter media 200 may preferably be disposed between the substrate soil 210 and the revetment mat 100. The upper surface 12 of the revetment block 10 is preferably parallel to the bottom surface 15 but may be designed differently depending on the application. In addition, the block 10 may have some catching features formed in the bottom surface 15 in order to increase the catching efficiency of the block 10 with the filter medium 200 or the matrix soil 210.

As shown in fig. 2 and 3, the upper surface 12 has at least one hole or opening 20 extending beyond the block 10 to the bottom surface 15. The at least one hole or opening 20 allows plants to grow through the block 10 from the substrate soil beneath the revetment mat 100 as shown in figure 4. In other words, the vegetation provides an anchor for the mat 100 and has a second advantage of making the appearance of the waterway aesthetically pleasing. Another advantage of the openings 20 is that the openings 20 release water pressure under the revetment mat 100. The openings 20 allow water to flow through the blocks, thereby relieving hydrostatic pressure below and reducing uplift forces on the revetment mat 100. A final advantage of the perforations or holes 20 is that they dissipate energy generated by, for example, waves that may impact the revetment mat 100. The at least one aperture 20 is preferably in equal proportion to the apertures 20 of the other revetment blocks 10 to provide an aesthetically pleasing appearance when forming a revetment mat.

The sidewalls 24a, 24b, 25a, 25b may taper entirely, but preferably include at least partially vertical sidewalls. The opposing side walls 24a, 24b are parallel and the opposing side walls 25a, 25b are parallel. In combination, the sidewalls 24a, 24b, 25a, 25b are preferably quadrilateral formed between the upper surface 12 and the bottom surface 15. In this embodiment, the side walls 24a, 25b have a vertical portion 21 and a tapered portion 22, the tapered portion 22 extending above the vertical portion 21 towards the upper surface 12 such that the surface area of the upper surface 12 is smaller than the bottom surface 15. In addition, the tapered section 22 also facilitates connection of the revetment block 10 to a matrix on a non-planar surface. The tapered portion 22 provides an aesthetically pleasing appearance and also serves to settle and fill the gaps between the blocks 10 with particles in the water. The sidewall 24b is a vertical sidewall and does not have a tapered portion similar to the sidewalls 24a, 25 b. Sidewall 24b has no tapered portion because its half dome 30 may abut an adjacent block having a half dome. In the opposite side walls 25a, 25b there are a number of recesses 26 and projections 28. The recess 26 is preferably U-shaped. As shown in fig. 2 and 3, the side 24a of the revetment block 10 preferably has three protrusions 28, the three protrusions 28 having a vertical portion 21 and a tapered portion 22 as previously described. Preferably, the side 24a also has a pair of U-shaped notches 23. Unlike the projections 28, however, the recesses 23 do not have tapered portions of the side walls. The recess 23 is actually half of the opening or hole 20 which is completely formed by the placement of adjacent blocks 10 in the revetment mat. As shown in fig. 2, the hole 20 has no tapered walls and therefore the recess 23 is not tapered. Also, the holes 20 and 18 are the same size on the bottom surface 15 of the block, but may be larger in size than the holes 18 on the top surface 12. Thus, the tapered sidewalls cause the size to decrease as the hole moves from the top surface 12 to the bottom surface 15.

Preferably, the opposing side walls 24b have a pair of recesses 38, the pair of recesses 38 having side walls 38a and tapered walls 39. Preferably, the opposing side wall 24b also has three projections 36. The projection 36 comprises a half dome 30, which half dome 30 can cooperate with an adjacent block 10 to form a full dome, as will be described in more detail below.

The opposite side wall 25a has at least one recess 26. Preferably, the two notches 26 are U-shaped channels and have curved corners 26 a. The U-shaped notches 26 provide for easy installation of adjacent interlocking blocks 10 of the revetment mat 100 and also provide for secure installation. Between the recesses 26 there are projections 28, which projections 28 also serve to interlock with adjacent blocks 10. In addition, the projections 28 and recesses 26 enable an offset running bond fit, which allows contact with at least four adjacent blocks. The protrusion 28 may be curved, U-shaped, angled, or otherwise shaped, so long as the recess 26 has a mating shape. Corner 27a is at the end of side 25 a. The corner 27a is recessed or truncated to form a half notch. When another adjacent revetment block 10 having an adjacent truncated corner is deployed, the entire channel or recess is formed by adjacent corner 27a into which protrusion 28 can easily fit to interlock revetment blocks 10 and stabilize revetment mat 100. The recesses 26 and projections 28 are preferably of equal proportions so that the block 10 can be interchanged with other blocks 10 of different manufacturing batches.

As shown in fig. 1, 3 and 4, at least one conduit or duct 40 extends between opposing sidewalls 25a and 25 b. The duct 40 extends through the side walls 25a and 25b so that the cords 42 can pass through to interlock the rows 102, 106 forming the revetment mat 100. Preferably, the conduit 40 is located in each recess 26 along the opposing sidewall 25b and extends through the protrusion 28 of the opposing sidewall 25 a. In this way, the conduit 40 is arranged not to pass through the apertures 18, 20, plants growing within the apertures 18, 20. The conduit 40 also allows water to flow through the block 10, thereby relieving hydrostatic pressure.

The opposite side wall 25b also has a plurality of projections 28 and recesses 26. Since preferably three conduits 40 extend from the protrusion 28 of the side wall 25a to the recess 26 of the side wall 25b, preferably three recesses 26 are provided along the side wall 25 b. The recess 26 is preferably channel shaped and has equal proportions to the recess 26 and the protrusion 28 along the side wall 25 a. This allows the blocks to be interchangeable and to interlock in both parallel bond and the preferred running bond scheme. Corner 27b is at the end of side wall 25 b. Unlike the truncated corners 27a, each corner 27b forms a half-lobe 28. This interlocks the revetment blocks 10 of a first row, e.g. row 102, with an adjacent row, e.g. row 106, and forms a mat, as best shown in fig. 4. When using a running joint lay-up, as shown in fig. 4, the standard size blocks 104, one half-size revetment block 10, and blocks 110 described below of the present invention may be in contact with at least four other blocks. This results in a more stable interlock and a stronger pad 100.

Referring again to fig. 2 and 3, at least one dome 13 extends upwardly from the upper surface 12 of the revetment block 10. The dome 13 is formed of precast concrete and may have a curved or tapered wall 14 extending from the upper surface 12 to a dome top or flat upper platform 16. The dome top 16 is generally planar and has at least one aperture 18, the aperture 18 extending from the dome top 16 through the bottom surface 15. The at least one aperture 18 is preferably substantially rectangular in shape, but may be any suitable shape that enables the plant to grow and release hydrostatic pressure. The holes 18 have: a pair of vertical walls 18a, the pair of vertical walls 18a being parallel to the side walls 25a and 25 b; and a pair of tapered walls 19, the pair of tapered walls 19 extending parallel to walls 24a and 24 b. The at least one aperture 18 also has the advantages described with respect to the at least one aperture 20, such as dissipating energy and releasing hydrostatic pressure. The dome 13 reduces the velocity of water flowing over the revetment mat 100 to prevent corrosion and dissipate energy. The dome 13 also reduces shear forces caused by water moving over the revetment mat 100. In addition, the slower flow rate through the pad 100 causes some particles to deposit on the pad and in its joints, thereby increasing its stability.

A half dome 30 also extends from upper surface 12. The dome 30 is formed from a curved wall 34, however, the curved wall 34 may alternatively be a tapered wall. Half dome 30 has at least one, and preferably two, recesses 38 formed by tapered wall 39 and recess wall 38 a. The tapered wall 39 tapers from a wider top portion to a narrower lower portion. Tapered wall 39 extends from dome top 36 to bottom surface 15 of revetment block 10. When revetment blocks having half-domes are arranged adjacently on end-adjacent half-domes 30, the half-domes 30 form the entire dome, for example dome 13. The half-dome 30 also slows the water flow rate over the revetment mat 100 and promotes the settling of particles in the apertures 18, 20 of the mat 100.

As best shown in fig. 4, there must be one half end block of both types. The right-hand block 10 has a matching left-hand block 110, the structure of the left-hand block 110 corresponding to a mirror image of the right-hand block 10. The main difference is that dome 13 and half-dome 30 are reversed such that half-dome 130 is on the left side of block 110 and full dome 113 is on the right side of block 110. As best shown in fig. 4, when block 10 is used in place of block 110, it is not properly aligned with the adjacent block of row 106. Thus, the left-hand block 110 is used to complete the revetment mat 100 having aligned edges.

As shown in fig. 5, 6 and 7, the left-hand block 110 is shown as a mirror image of block 10. The left hand revetment block 110 has a top surface 112, a bottom surface 115 and four sidewalls 124a, 124b, 125a, 125 b. Referring to fig. 6, full dome 113 is shown on the right side of block 110, and half dome 130 is shown on the left side of block 110, as opposed to the configuration of block 10. The block 110 includes apertures 118, 120 corresponding to the apertures 18, 20 of the block 10. The block 110 also includes three notches 126 along side 125b and three opposing projections 128 along side 125 a. This configuration allows proper alignment of the openings and domes in the revetment mat 100. Moreover, it is also possible to properly align the ducts 40 so that the cords 42 can extend through the entire revetment mat 100.

Bank protection pad

The plurality of interlocked revetment blocks 10,110 form a revetment mat, matrix or mat 100 as shown in figure 4. The pad 100 may be formed from only the blocks 10, 110, but is preferably formed using smaller standard size blocks 104, the standard size blocks 104 also having two protrusions on the top side wall and two recesses on the bottom side wall. As shown in fig. 4, the preferred method of forming the mat 100 is running bond. The running bond is formed by offset rows of revetment blocks such that the pads interlock and the blocks 10,104, 110 are in contact with at least four other blocks. However, when the same number of blocks are used in each row, running bond results in rows that are not uniformly aligned. More specifically, alternating rows are short halves at each end, requiring half blocks to be added. However, as mentioned above, this presents problems associated with using half-size blocks, as shown in FIG. 8.

The mat 100 may be formed from revetment blocks 10, 104, 110. In alternate rows, the revetment blocks 10, 110 use revetment blocks 10, 110 at the ends of row 106 to provide uniform alignment of the rows of mats 100 without using half-sized blocks. Thus, problems associated with half-sized blocks, such as lifting and twisting of the half-block and curling of the pad edges, are prevented due to the shear resistance provided by the blocks 10, 110.

The revetment mat 100 comprises a first row 102 of standard size revetment blocks 104. The first row 102 may be any suitable length for a given application, while the mat 100 may include any suitable number of rows. A second row 106 is formed with a left hand half-size revetment block 110 at the left end of row 106, a plurality of standard size blocks 104 and a right hand half-size revetment block 10 at the right end of second row 106 to align row 106 evenly with row 102.

The revetment mat 100 is constructed in rows until a square matrix of suitable dimensions is obtained. The structure of the mat 100 may preferably be formed at the manufacturing facility, but may also be formed at the mat installation site. When the rows 102, 106 are complete, the cord 42 is disposed through the conduit 40. Alignment of the notches 26 and protrusions 28 of adjacent rows aligns the conduits 40 of the plurality of blocks 10. By using revetment blocks 10,110 at each end of alternating rows, mat 100 is formed with aligned edges without using half-sized blocks, as shown in fig. 8.

Alternatively, the revetment mat 300 may be formed from the blocks 10,110 only, as shown in figure 10. The rows 306 of revetment mats 300 are formed by arranging the right hand blocks 10 and left hand blocks 110 in an alternating manner. The interlocking form of the blocks 10, 110 also enables the conduits 40 to be aligned so that the cable 42 can be used to interlock the blocks 10, 110. As shown in fig. 10, the revetment mat 300 may be bonded in parallel so that the edges of the revetment mat are aligned.

Once the precast blocks are constructed into mats 100 or 300, cords 42 are used to interlock the rows of mats 100. Preferably, the rope is stainless steel, but may alternatively be made of galvanized stainless steel or high strength polyester rope. In addition, the rope or rope has good properties against most acids, alkalis and solvents and should also be impervious to rot, mildew, microbes and marine environments. The cord 42 preferably extends through the conduit 40 when the mat 100 is fully formed. For example, the rope 42 may begin at the sidewall 25b of the first row and extend through the duct 40 for the length of the revetment mat 100. At an opposite end of the mat 100, the cord may exit the conduit 40, for example at side 25 a. In each duct 40, a pad 46 or sleeve 44 may be disposed on the rope 42 at the point where the rope 42 enters and exits the revetment mat 100, as shown in fig. 9. Preferably, the sleeve 44 snaps over the cord 42 near the conduit aperture 40, thereby preventing the cord 42 from moving freely through the mat 100. This process continues until the pad 100 is fully constructed.

Once completed, the filter media or filter fabric 200 is placed over the substrate soil at the location where the mat 100 will be placed. The filter fabric 200 prevents the substrate soil 210 from being corroded and is preferably made of a geotextile comprising a synthetic polymer such as propylene, ethylene, ester, or amide and an inhibitor in order to prevent deterioration due to ultraviolet rays and heat. Once the filter fabric 200 is placed, the mat 100 is moved (preferably by a trowel) by a crane or other lifting motion device to be placed on the filter fabric 200. Finally, pad 100 is lowered into the water course, ramp, or channel and placed on top of filter fabric 200. In an alternative embodiment, the mat 100 may be constructed on-site, rather than at a manufacturing facility. As previously described, the blocks comprising mat 100 may have projections on bottom surface 15 to increase the shear force resistance to flowing water.

The foregoing description is given primarily for clearness of understanding and no unnecessary limitations are to be understood therefrom for modifications will become obvious to those skilled in the art upon reading this disclosure and may be made without departing from the spirit of the invention and scope of the appended claims.

Claims (8)

1. A revetment mat comprising:

at least one first row of standard-sized blocks;

at least one second row of said standard-sized blocks having a half-sized end block at the end of the second row that is about one and one-half times larger than said standard-sized blocks;

the revetment mat is defined by alternating the at least one first and second rows in a running bond with evenly aligned edges.

2. The revetment mat of claim 1, wherein the end block comprises:

two U-shaped notches in first and second opposing parallel sides;

a third side having three protrusions;

a fourth side having three U-shaped notches opposite the three protrusions of the third side;

said third and fourth sides being opposed parallel sides each having an upper portion and a lower portion, said upper portions of said third and fourth sides tapering inwardly;

each end of the third side defines a half-sized U-shaped notch and each end of the fourth side defines a half-sized protrusion;

the top surface of the at least one block having a dome with first and second openings extending downwardly through the dome;

a half dome disposed on the top surface opposite the dome;

wherein two of said U-shaped notches extend through said half dome;

said top surface including third and fourth openings extending downwardly and located between said dome and said half-dome;

the two U-shaped notches of the half dome are about half the size of the first and second openings;

the notch extends through the half dome and is sized to be about half of the opening extending through the dome.

3. The revetment mat of claim 1, wherein the standard size block has: first and second sides comprising two notches; a third side having two protrusions; and a fourth side having two notches.

4. The revetment mat of claim 6, wherein: the standard-sized block and the end block further include adjacent partially tapered sidewalls.

5. The revetment mat of claim 1, further comprising: a cord that interlocks the blocks.

6. The revetment mat of claim 1, wherein: the at least one end block prevents the edge of the revetment mat from curling.

7. The revetment mat of claim 1, wherein: the pad is formed of precast concrete.

8. A revetment mat having at least one half-size end block comprising:

a plurality of alternating first and second rows of blocks forming a pad;

the first row comprises a plurality of first sized blocks having first and second sides with two notches, a third side with two projections, and a fourth side with two notches;

the second row includes: a right hand half size block at the right end of the second row and a left hand half size block at the left end of the second row; and a plurality of standard size blocks extending between the right hand block and the left hand block;

the first and second rows of bricks are bonded by pressure joints;

the pad having a right hand side edge and a left hand side edge that are substantially uniformly aligned;

the one half-size block is about one and one-half times larger than the first-size block;

wherein the one half-size block comprises:

two U-shaped notches in first and second opposing parallel sides;

a third side having two U-shaped notches defined by projections;

a fourth side having three U-shaped notches defined by projections;

said third and fourth sides being opposed parallel sides each having an upper portion and a lower portion, said upper portion tapering inwardly;

each end of the third side defines a half-sized U-shaped notch and each end of the fourth side defines a half-sized protrusion;

the top surface of the block having a dome with first and second openings extending downwardly through the dome;

a half dome disposed on the top surface opposite the dome;

said half dome having two of said U-shaped notches extending therethrough;

said top surface including third and fourth openings extending downwardly and located between said dome and said half-dome;

the notch of the half dome has a size of about half of the first and second openings.