US RE39922 E1
A segmental retaining wall system comprising a plurality of wall blocks. Each wall block comprises an interior face for forming an interior surface of a segmental retaining wall, an exterior face for forming an exterior surface of the segmental retaining wall, first and second sides that extend from said exterior face to said interior face, a top surface, and a bottom surface. In addition, a plurality of wall blocks include apparatus for retaining a reinforcement member to the segmental retaining wall. In one arrangement, this apparatus comprises a channel that is defined by a front wall, a rear wall, and a channel bottom surface. This channel is provided in one of the faces and surfaces, and includes an inwardly extending shoulder.
1. A wall block for use in a segmental retaining wall system, said wall block comprising:
an interior block face for forming an interior surface of a segmental retaining wall;
an exterior block face for forming an exterior surface of the segmental retaining wall;
first and second block sides that extend from said exterior block face to said interior block face;
a block top surface and having a lock channel formed therein, the lock channel being defined by a channel front wall, a channel rear wall, and a channel bottom surface, the lock channel extending transversely across the block top surface from the first block side to the second block side, wherein the channel front wall forms a first shoulder that extends towards the interior block face so as to overhang a portion of the channel front wall, wherein the channel rear wall forms a second shoulder that extends towards the exterior block face so as to overhang a portion of the channel rear wall, and wherein the shoulders are spaced apart and run generally parallel to each other along the lock channel;
a block bottom surface; and
a channel defined by a front wall, a rear wall, and a channel bottom surface and extending across one of said faces and surfaces, said rear wall including an inwardly extending shoulder.a lock flange on the bottom surface of the block, the lock flange being defined by a flange front surface extending from the block bottom surface, a flange rear surface extending from the block bottom surface, and a flange bottom surface extending between the flange front and rear surfaces, the lock flange extending transversely across the block bottom surface in substantially the same direction as the lock channel, the lock flange being sized, shaped, and positioned so that the flange will fit into the lock channel of a similarly configured wall block in an adjacent lower course when the lock flange is passed downwardly through the space between the first and second shoulders of the similarly configured wall block and into the lock channel of that wall block from above, and wherein the flange front surface includes a portion that is sized and shaped so as to engage the first shoulder of the lock channel of the similarly configured block either directly, or indirectly if a portion of a soil reinforcement member is interposed between the flange front and the first shoulder, such that when the wall block is stacked atop the similarly configured block the wall block is properly aligned thereon.
2. The wall block of
3. The wall block of
4. The wall block of
5. The wall block of
6. The wall block of
7. The wall block of claim 6 1, wherein said front wall the first shoulder is formed as a curved lip.
8. The wall block of
9. The wall block of
10. The wall block of
11. A segmental retaining wall system comprising:
a wall block including:
an interior face for forming an interior surface of a segmental retaining wall;
an exterior face for forming an exterior surface of the segmental retaining wall;
first and second sides that extend from said exterior face to said interior face;
a top surface and a bottom surface; and
retaining means for retaining a reinforcement member to the wall block, said retaining means including a channel defined by a front wall, a rear wall, and a channel bottom surface and extending across one of said wall block faces and surfaces, at least one of said front wall and rear wall having an inwardly extending shoulder associated therewith.
12. The system of
13. The system of
14. The system of
15. The system of
16. The system of
17. The system of claims 11, 14, or 16 wherein said inwardly extending shoulder is integrally formed with its associated channel wall.
18. The system of
19. The system of
20. The system of
21. A method for forming a segmental retaining wall, said method comprising the steps of:
stacking a plurality of wall blocks in aligned courses, a plurality of said wall blocks having a channel formed therein, the channel including at least one inwardly extending shoulder; and
securing at least one reinforcement member to the wall with a retaining bar that overlaps the reinforcement member within the channel;
wherein the retaining bar in cooperation with the channel secures the reinforcement member to the wall when tensile forces are imposed upon the reinforcement member.
22. The method of
This is a continuation-in-part of U.S. patent application Ser. No. 09/049,627, filed Mar. 27, 1998 now U.S. Pat. No. 6,089,793.
The invention relates generally to earth retaining walls. More particularly, the invention relates to a segmental retaining wall system comprising retaining means for attaching reinforcement members to the retaining wall.
Segmental retaining walls commonly are used for architectural and site development applications. Such walls are subjected to very high pressures exerted by lateral movements of the soil, temperature and shrinkage effects, and seismic loads. Therefore, the wall is often tied into the backfill soil, typically with tensile reinforcement members. Usually, elongated structures, commonly referred to as geogrids or reinforcement fabrics, are used to provide this reinforcement. Geogrids often are configured in a lattice arrangement and are constructed of a metal or plastic, while reinforcement fabrics are constructed of a woven or non-woven polymer fibers or plastics. These reinforcement members typically extend rearwardly from the wall and into the soil to stabilize the soil against movement and thereby create a more stable soil mass which results in a more structurally secure retaining wall.
Although several different forms of reinforcement members have been developed, difficulties remain with respect to attachment of the members to retaining walls. In particular, the reinforcement members can shift out of position and be pulled away from the retaining wall due to movement of the soil. This difficulty especially can be problematic in areas of high seismic activity where a poorly secured gravity wall can topple. In response to this problem, several current retaining wall systems have been developed to retain geogrid reinforcement members. In one such system, rake shaped connector bars are positioned transversely in the center of the contact area between adjacent stacked blocks with the prongs of the connector bars extending through elongated apertures provided in the geogrid in position under normal conditions, this system of attachment provides a substantial drawback. Specifically, the geogrids of this system only extend along the back halves of the contact areas between the blocks. Although the geogrids are relatively thin, this partial insertion of the geogrids can cause the retaining wall to bow outwardly due to the aggregate thickness of the geogrids. As can be appreciated, this outward bowing can be substantial with tall retaining walls that require a multiplicity of geogrids. Aside from creating the impression of instability, this condition increases the likelihood of wall failure, particularly in response to seismic activity.
From the above, it can be appreciated that it would be desirable to have a mechanically stable wall system having secure retaining means for maintaining connection of reinforcement members to the retaining wall.
Briefly described, the present invention relates to a segmental retaining wall system. This system comprises a plurality of wall blocks. Each wall block comprise an interior face for forming an interior surface of a segmental retaining wall, an exterior face for forming an exterior surface of the segmental retaining wall, first and second sides that extend from said exterior face to said interior face, a top surface, and a bottom surface. In addition, the wall block includes retaining means for retaining a reinforcement member to the segmental retaining wall. In one arrangement, these retaining means comprises a channel that is defined by a front wall, a rear wall, and a channel bottom surface. This channel is provided in one of the faces and surfaces of the block, and preferably includes at least one inwardly extending shoulder.
The objects, features, and advantages of this invention will become apparent upon reading the following specification, when taken in conjunction with the accompanying drawings.
Referring now in more detail to the drawings, in which like numerals indicate corresponding parts throughout the several views,
Generally speaking, the wall blocks 12 are substantially identical in size and shape for ease of block fabrication and wall construction. Accordingly, each block 12 typically is configured so as to mate with vertically adjacent blocks when the blocks are stacked atop one another to form the retaining wall 10. Referring to
The top and bottom surfaces 28 and 30 of each block 12 typically are parallel to each other so that, when stacked on top of one another, an upright wall 10 is formed. Similarly, the opposed sides 32 typically are parallel to each other. However, the opposed sides 32 can be inwardly or outwardly tapered from the exterior face 24 of the block 12 to the interior face 26 of the block to form curved walls of nearly any shape. Preferably, the wall blocks 12 further include interior openings 34 which reduce the amount of concrete or other materials needed to fabricate the blocks and reduce the weight of the blocks to simplify wall construction. Although depicted in the figures as being arranged in a horizontal orientation, these openings could be arranged in a vertical orientation, if desired.
As mentioned above, the wall blocks 12 typically comprise retaining means for attaching reinforcement members (e.g., geogrid) to the retaining wall 10. These retaining means include a channel 16. Typically, each block 12 has a channel 16 provided in its top surface 28, although alternative placement is feasible. By way of example, the channel 16 alternatively could be provided in the bottom surface 30 or the interior face 26 of the wall block 12. When provided in the interior face 26 of the block 12, the channel 16 can be arranged either horizontally or vertically therein, although horizontal placement is preferred. When the channel 16 is provided in the top surface 28, however, the channel normally extends transversely across the block 12 from one side 32 of the block to the other, usually parallel to the exterior surface 15 of the block 12. As illustrated in
Positioned opposite the front wall 36, the rear wall 38 of the channel 16 preferably similarly includes an inwardly extending shoulder 45. The rear wall shoulder 45 preferably is arranged as a curved lip so as to form a second substantially arcuate edge 46 of the channel 16. Although the shoulders 42, 45 have been described herein as being arranged as curved lips, it will be apparent from the present disclosure that these shoulders alternatively could be arranged as inwardly extending flanges or other such protrusions. Furthermore, depending upon the particular implements used to retain the reinforcement members, the placement of the channel 16, and the degree of block-to-block locking desired, the walls 36, 38 can be formed without such shoulders 42, 45 to simplify block construction. For example, if the channel 16 is not used to facilitate block-to-block locking, the front wall 36 can be substantially planar in shape in that it does not serve the retaining function that the rear wall 38 serves (see FIG. 9).
Where block-to-block locking is desired, the front wall 36 typically includes a shoulder 42 that is adapted to receive a flange 18 that extends from the block 12. In a preferred embodiment, the flange 18 is provided on the bottom surface 30 of the block 12 and, like the channel 16, extends transversely from one side 32 of the block to the other side 32. As is illustrated in
The retaining means of the disclosed system typically further include a reinforcement member retaining bar 22, shown most clearly in FIG. 6. As indicated in this figure, the retaining bar 22 specifically is sized and configured to fit within the channel 16. In a preferred arrangement, the retaining bar 22 has a plurality of different surfaces: a top surface 54, a bottom surface 56, a first upright surface 58, a second upright surface 60, a first oblique surface 62, and a second oblique surface 64. Normally, the top surface 54 and the bottom surface 56 are parallel to each other as are the first oblique surface 62 and the second oblique surface 64. Similarly, the first upright surface 58 and the second upright surface 60 typically are parallel to each other such that the first upright surface extends perpendicular from the top surface 54 and the second upright surface extends perpendicularly from the bottom surface 56. Configured in this manner, the retaining bar 22 can be positioned on top of a reinforcement member 20 in the channels 16 by inserting the retaining bar into the channels with the second upright surface 60 forward, and twisting the bar downwardly into place as depicted in FIG. 7. In that the bar 22 is designed to fit closely between the front and rear walls 36 and 38 of the channels 16 when in place, a longitudinal notch 46 is provided in the channel 16 to accommodate the second upright surface 60 during the twisting and downward insertion of the bar.
Once correctly inserted within the channel 16, the first upright surface 58 and the second oblique surface 64 of the retaining bar 22 hold the reinforcement member 20 against the front and rear walls 36 and 38 of the channel, respectively, as shown in FIG. 7. In embodiments in which the flange 18 is not provided, the channel 16 can have a relatively shallow depth dimension. The retaining bar 22 prevents the reinforcement member 20 from being pulled out from the retaining wall 10. Specifically, when a tensile force is applied to the reinforcement member 20 from the soil side of the retaining wall 10, the retaining bar 22 is rotated within the channel 16 to cause the reinforcement member to be clamped by member 20 to the sides of the channel, locking the reinforcement member in place. In that the amount of pressure that is applied on the retaining bar 22 is not large, the retaining bar can be constructed of a polymeric material such as nylon 6,6 or high density polyethylene. Use of such a polymeric material provides the additional advantage of providing for a lightweight, inert retaining bar.
The system of the present invention can be used to construct any number of different configurations of segmental retaining walls.
After the starting course has been formed with either the starting blocks 70 or wall blocks 12, the next course of blocks can be laid. The wall blocks 12 are placed on top of the blocks of the starting course with the flanges 18, if provided, extending into the channels 16 of the lower blocks. As can be appreciated from
Once the first wall course has been formed atop the starting course, backfill soil, S, can be placed behind the blocks 12. Typically, a non-woven filter fabric 72 is provided between the wall 66 and the backfill soils to prevent the introduction of particulate matter between the courses of blocks due to water migration within the soil. Alternatively, a layer of gravel aggregate can be provided between the wall and the soil to serve the same function. Additional ascending courses thereafter are laid in the manner described above. Although alternative configurations are possible, a reinforcement member 20 typically is laid between every other course of blocks 12 as indicated in FIG. 8. It will be appreciated, however, that greater or fewer reinforcement members 20 can be provided depending upon the particular reinforcment needs of the construction site. Preferably, these reinforcement members 20 are composed of a flexible polymeric fabric. As described above, the reinforcment members 20 are positioned so that they extend from the exterior surface 15 of the retaining wall, into the channel 16, and past the exterior surface 17 of the retaining wall to extend into the soil. As shown most clearly in
Construction of the retaining wall 66 continues in this manner until the desired height is attained. As indicated in
While preferred embodiments of the invention have been disclosed in detail in the foregoing description and drawings, it will be understood by those skilled in the art that variations and modifications thereof can be made without departing from the spirit and scope of the invention as set forth in the following claims. For instance, although particular block configurations have been identified herein, persons having ordinary skill in the art will appreciate that the concepts disclosed herein, in particular the retaining means described herein, are applicable to prior and future wall block designs.