Abstract:
A retaining wall anchoring system for a segmental retaining wall comprising a plurality of tieback rods adapted to be embedded into soil or rock with a proximal portion extending therefrom, at least one elongated force distribution member positionable directly adjacent the proximal portion of at least one of the tieback rods, a washer positionable about the proximal portions of the tieback rod in abutment with the force distribution member, and a fastener fixedly securable to the proximal portion of the tieback rod to securely clamp the washer against the force distribution member such that tensile forces imposed on the tieback rod are transmitted to the force distribution member so as to distribute these forces throughout a portion of the retaining wall.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
   This application is a continuation of U.S. patent application Ser. No. 09/698,934 filed Oct. 27, 2000, entitled “Retaining Wall Anchoring System”, now U.S. Pat. No. 6,652,196, which is a continuation of U.S. patent application Ser. No. 09/261,420, filed Mar. 3, 1999, now U.S. Pat. No. 6,168,351, entitled “Retaining Wall Anchoring System”, which is a continuation-in-pan of U.S. application Ser. No. 08/846,440, filed Apr. 30, 1997, now U.S. Pat. No. 5,921,715, entitled “Retaining Wall and Method” and which claims the benefit of the filing date of U.S. Provisional Application Ser. No. 60/086,843, filed May 27,1998, entitled “Retaining Wall Anchoring System”, all of which are incorporated herein by reference. 

   FIELD OF THE INVENTION 
   The invention relates generally to earth reinforcement. More particularly, the invention relates to a segmental retaining wall anchoring system for securing segmental retaining walls. 
   BACKGROUND OF THE INVENTION 
   Segmental earth retaining walls are commonly 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 backfill soil typically must be braced with tensile reinforcement members. 
   Often, 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 polymer, while reinforcement fabrics are constructed of woven or nonwoven polymers (e.g., polymer fibers). These reinforcement members typically extend rearwardly from the wall and into the soil. The weight of the soil constrains the fabric from lateral movement to thereby stabilize the retaining wall. 
   SUMMARY OF THE INVENTION 
   Briefly described, the present invention relates to a retaining wall anchoring system for a segmental retaining wall comprising a plurality of tieback rods adapted to be embedded into soil or rock with a proximal portion extending therefrom. The system includes at least one elongated force distribution member positionable directly adjacent the proximal portion of the tieback rods, at least one washer positionable about the proximal portions of at least one tieback rod in abutment with the force distribution member, and at least one fastener fixedly securable to the proximal portion of the tieback rod to securely clamp the washer against the force distribution member such that tensile forces imposed on the tieback rod are transmitted to the distribution member so as to distribute these forces throughout a portion of the retaining wall. 
   The above described apparatus therefore can be used to construct a segmental retaining wall system comprising a retaining wall having a plurality of wall blocks stacked in ascending courses with a plurality of the wall blocks being provided with interior openings that are aligned with each other to form an inner passageway within the retaining wall. The proximal portion of each tieback rod can be extended into the inner passageway formed within the retaining wall with the elongated force distribution member positioned within the inner passageway directly adjacent the proximal portion of at least one of the tieback rods, a washer positioned about the distal portion of the tieback rods in abutment with the force distribution member, and a fastener fixedly secured to the proximal portion of the tieback rods to securely clamp the washer against the force distribution member such that tensile forces imposed on the tieback rods are transmitted to the force distribution member so as to distribute the tensile forces throughout a portion of the retaining wall. 
   In addition, the apparatus can be used to construct a segmental retaining wall system comprising a retaining wall having a plurality of wall blocks stacked in ascending courses to form an interior surface and an exterior surface, a plurality of tieback rods adapted to be embedded into soil or rock with a proximal portion extending therefrom, the proximal portion of each tieback rod extending toward the interior surface of the retaining wall, at least one elongated force distribution member positioned adjacent the interior surface of the retaining wall and directly adjacent the proximal portion of at least one tieback rod, a washer positioned about the distal portion of the tieback rod in abutment with the force distribution member, a fastener fixedly secured to the proximal portion of the tieback rod to securely clamp the washer against the force distribution member, and a reinforcement member connected to the force distribution member and being securely attached to the retaining wall such that tensile forces imposed on the tieback rods are transmitted to the force distribution member and through the reinforcement member to the retaining wall so as to distribute the tensile forces throughout a portion of the retaining wall. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a front view of a retaining wall secured with an anchoring system constructed in accordance with the present invention. 
       FIG. 2  is a partial cross-sectional view of a retaining wall which shows a tieback connection of an anchoring system constructed in accordance with the present invention. 
       FIG. 3  is a partial cross-sectional view of a retaining wall secured with an anchoring system constructed in accordance with the present invention. 
       FIG. 4  is a partial cross-sectional view of a retaining wall which shows a tieback connection of an anchoring system constructed in accordance with the present invention. 
   

   DETAILED DESCRIPTION 
   Referring now in detail to the drawings, in which like numerals indicate corresponding parts throughout the several views,  FIG. 1  illustrates a modular retaining wall  10  secured with a first embodiment  12  of an anchoring system constructed in accordance with the present invention. As depicted in this figure, the retaining wall  10  comprises a plurality of wall blocks  14  that are stacked atop each other in ascending courses  16 . When stacked in this manner, the wall blocks  14  together form an exterior surface  18  of the wall  10  which faces outwardly away from an earth embankment, and an interior surface  20  of the wall  10  which faces inwardly toward the embankment (FIG.  3 ). Typically, the blocks  14  are stacked in a staggered arrangement as shown in  FIG. 1  to provide greater stability to the wall  10 . 
   Generally speaking, the blocks  14  are substantially identical in size and shape for ease of block fabrication and wall construction, although it will be understood that unidentical blocks could be used, especially for cap blocks or base blocks. In a preferred configuration, each block  14  is configured so as to mate with at least one other block  14  when the blocks are stacked atop one another to form the retaining wall  10 . This mating restricts relative movement between vertically adjacent blocks in at least one horizontal direction. To provide for this mating, the blocks  14  can include locking means  22  that secure the blocks together to further increase wall stability. More particularly, each block  14  can include a lock channel  24  and a lock flange  26  that are configured so as to positively lock with each other when the blocks  14  are stacked on top of each another as disclosed in co-pending U.S. application Ser. No. 09/049,627, which is hereby incorporated by reference into the present disclosure. When the blocks  14  include lock channels  24  and flanges  26 , the individual lock channels typically form a continuous lock channel that extends the length of the lower of two mating courses when the blocks are aligned side-byside within each course  16 . Similarly, the lock flanges  26  form a continuous lock flange that extends the length of the upper of the mating courses  16  which is received by the continuous lock channel of the lower of the mating courses. 
   Although the blocks  14  preferably are provided with such locking means  22 , it will be appreciated that the anchoring system of the present invention can be used with substantially any segmental retaining wall blocks. By way of example, the present system could be used with any of the blocks produced by Anchor Wall Systems, Inc. such as any block of the Anchor Diamond® and/or Anchor Vertica® product lines, or any block disclosed in U.S. Pat. No. 5,827,015, which is hereby incorporated by reference into the present disclosure. Moreover, the present system could be utilized with the segmental blocks produced by other manufacturers such as Keystone, Mesa, Versa-Lok, Newcastle, and Piza. Irrespective of the particular configuration of the wall blocks  14 , each of the wall blocks typically includes an interior opening  32  that either extends through the block horizontally (side-to-side) or vertically (top-to-bottom). When the blocks  14  are correctly aligned in their respective courses  16 , these openings  32  form continuous elongated passageways  34 . In that, as described below, the passageways  34  typically are only used for anchoring system attachment, it is to be appreciated that only the blocks  14  that receive the system&#39;s components need be provided with such openings  32 . 
   As indicated in  FIGS. 1-3 , the retaining wall  10  is secured in several predetermined points with tieback connections  36 . Typically, each tieback connection  36  is spaced approximately 10 feet apart horizontally from each other to form rows of tieback connections that are approximately 2.5 feet apart vertically from each other. Accordingly, each tieback rod  38  is embedded into the soil and/or rock in these intervals. As shown in  FIG. 2 , each tieback rod  38  extends through an opening  39  formed in the rear surface of its respective wall block  14  such that a proximal portion  40  of the rod  38  extends into the continuous elongated passageway. Also positioned within the passageway  34  is a tieback rod attachment mechanism  42 . The attachment mechanism  42  normally includes a pair of elongated force distribution members  44 ,  46  that extend from one tieback rod  26  to the next along the passageway  34  and which are positioned above and below the tieback rods  38  as indicated in FIG.  1 . Typically, each force distribution member  44 ,  46  comprises an elongated channel beam that is flanged so as to cooperate more readily with washers described below. Arranged in this manner, each passageway  34  having tieback rods  38  extending therein includes a plurality of force distribution members  44 ,  46  aligned end to end both above and below the rods. To maintain parallel spacing between the force distribution members  44 ,  46 , the attachment mechanism  42  can include spacers  47  that are positioned adjacent each rod  38  on both sides of the rod as indicated in FIG.  1 . Normally, the height of these spacers  47  generally approximates the diameter of the tieback rods  38 . 
   As shown in  FIG. 2 , a pair of flanged washers  48 ,  50  partially surround the upper and lower pairs of force distribution members  44  and  46 , and are fitted about each tieback bar  38 . To accommodate the rearmost  50  of the washers, each wall block  14  accommodating a tieback rod  38  normally is provided with an inner channel  54  that is sized and configured for receipt of the washer  50 . Threaded onto each tieback rod  38  is a conventional threaded fastener  56  such as a nut which, when fully tightened, urges the washers  48 ,  50  inwardly to securely hold the force distribution members  44 ,  46  in position, thereby securing the rod to the wall  10 . Normally, this tightening is achieved by accessing the interior of the block  14  by removing a face covering portion  57  of the block. Once fully tightened, the fastener  56  can be bonded in place with epoxy to prevent its inadvertent loosening. After the fastener  56  has been fixed in place, the face covering portion  57  of the block  14  can be secured to the block so that it matches the other blocks forming the wall. Configured in this manner, each tieback connection  36  evenly distributes any forces exerted on the tieback rods  38  throughout the wall  10  to greatly improve wall integrity. 
     FIG. 4  illustrates a second embodiment  58  of an anchoring system constructed in accordance with the present invention. This embodiment is structurally similar to the system depicted in  FIGS. 1-3  and described above. Accordingly, the force distribution members  44 ,  46 , flanged washers  48 ,  50 , as well as the fastener  56 , are used to secure the tieback rods  38  to the wall  10 . However, in this embodiment, the rods  38  are secured with a reinforcement member  60  such as a geogrid wrap instead of directly to a wall block  14  such that the reinforcement member  60  is positioned outside of but adjacent to the interior surface  20  of the wall. Because of this arrangement, the blocks  14  need not comprise interior openings  32 , as in the first embodiment. Preferred for the construction of the reinforcement member  60  is geogrid material that comprises flexible fabric composed of a polymeric material such as polypropylene or high tenacity polyester. As shown most clearly in  FIG. 4 , the reinforcement member  60  extends from the exterior surface  18  of the retaining wall  10 , into a lock channel  24  of the lower adjacent wall block  14 , out from the wall and into a portion of the stone fill  62  formed between the wall and the soil and/or rock, wraps around the force distribution members  44 ,  46 , and then extends back underneath the upper adjacent block  14  (into the wall), into the lock channel  24  of the upper adjacent block, and back to the exterior surface of the wall  18 , tracing a substantially C-shaped path. 
   In the wall system illustrated in  FIG. 4 , the reinforcement member  60  is locked to the wall  10  with a pair of retaining bars  64  that are positioned in the two lock channels  24  adjacent the tieback rod  38 . These retaining bars  64  lie atop the reinforcement member  60  and holds it against the rear walls of the locking channels  24  to prevent the reinforcement member from being pulled out from the retaining wall  10 . Although such retaining means are preferred, it will be understood that other types of retaining means could be used. When a tensile force is applied to the tieback rod  38  and translated to the reinforcement member  60 , the retaining bars  64  are urged towards the rear wall of the channels  24 , locking the reinforcement member in place. Thus, like the system of the first embodiment, the anchoring system of the second embodiment similarly distributes the forces exerted by the soil and/or rock of the embankment throughout the retaining wall  10 . 
   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. For instance, although the anchoring system of the first embodiment herein is described and shown in use with a retaining wall having horizontal inner passageways, it is to be appreciated that this systems easily could be adapted for use with a retaining wall having vertical inner passageways.