Patent Publication Number: US-6336773-B1

Title: Stabilizing element for mechanically stabilized earthen structure

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This is a continuation application to U.S. patent application Ser. No. 09/153,271, filed on Sep. 14, 1998, which is a continuation of U.S. patent application Ser. No. 08/472,885, filed on Jun. 7, 1995 and issued as U.S. Pat. No. 5,807,030, which is a continuation-in-part of Ser. No. 08/040,904, filed on Mar. 31, 1993 and issued as U.S. Pat. No. 5,507,599, a continuation-in-part of Ser. No. 08/108,933, filed on Aug. 18, 1993 and issued as U.S. Pat. No. 5,487,623, a continuation-in-part of Ser. No. 08/192,801, filed on Feb. 14, 1994 and issued as U.S. Pat. No. 5,624,211, a continuation-in-part of Ser. No. 08/137,585, filed on Oct. 15, 1993 and issued as U.S. Pat. No. 5,474,405, a continuation-in-part of Ser. No. 08/382,985, filed on Feb. 3, 1995 and issued as U.S. Pat. No. 5,586,841. Ser. No. 08/468,633, filed on Jun. 6, 1995 issued as U.S. Pat. No. 5,577,866 is a related case. Related cases are U.S. patent application Ser. No. 08/475,045, filed on Jun. 6, 1995 and issued as U.S. Pat. No. 5,622,455, which is a continuation-in-part of Ser. No. 08/466,806, filed Jun. 6, 1995 and issued as U.S. Pat. No. 5,494,379, which is a continuation of Ser. No. 08/156,053, filed Nov. 22, 1993 and now abandoned. Each of these patents and patent applications are incorporated herein by reference. 
    
    
     BACKGROUND OF THE INVENTION 
     This invention relates to an improved retaining wall construction and, more particularly, to a retaining wall construction comprised of modular blocks, in combination with tie-back and/or mechanically stabilized earth elements and compacted particulate or soil. This invention further relates to the stabilizing elements for mechanically stabilized earthen structures and the combination thereof with various facing elements. 
     In U.S. Pat. Nos. 3,686,873 and 3,421,326, Henri Vidal discloses a constructional work now often referred to as a mechanically stabilized earth or earthen structure. The referenced patents also disclose methods for construction of mechanically stabilized earth structures such as retaining walls, embankment walls, platforms, foundations, etc. In a typical mechanically stabilized earth construction, particulate earthen material interacts with longitudinal elements such as elongated steel strips positioned at appropriately spaced intervals in the earthen material. The elongate elements are generally arrayed for attachment to reinforced precast concrete wall panels and, the combination forms a cohesive embankment and wall construction. The longitudinal or elongate elements, which extend into the earthen work, interact with compacted soil particles principally by frictional interaction and thus mechanically stabilize the earthen work. They are often termed stabilizing elements. The elongate, longitudinal or stabilizing elements may also perform a tie-back or anchor function. 
     Various embodiments of the Vidal development have been commercially available under various trademarks including the trademarks, REINFORCED EARTH embankments and RETAINED EARTH embankments. Moreover, other constructional works of this general nature have been developed. By way of example and not by way of limitation, Hilfiker in U.S. Pat. No. 4,324,508 discloses a retaining wall comprised of elongated panel members with wire grid mats attached to the backside of the panel members projecting into an earthen mass. 
     Vidal, Hilfiker and others generally disclose large precast, reinforced concrete wall panel members cooperative with strips, mats, etc. to provide a mechanically stabilized earth construction. Vidal, Hilfiker and others also disclose or use various shapes of precast concrete wall panel members. It is also noted that in constructions disclosed by Vidal and Hilfiker, the elements interactive with the compacted earth or particulate behind the wall panels or blocks, are typically rigid steel strips or mats which rely upon friction and/or anchoring interaction with the particulate, although ultimately, all interaction between such elements and the earth or particulate is dependent upon friction. Wire mats or mesh are also disclosed as vertical facing elements in place of the concrete panel members. 
     In such circumstances, smaller precast blocks rather than large precast panels may be used to define the wall. Forsberg in U.S. Pat. No. 4,914,876 discloses the use of smaller retaining wall blocks in combination with flexible plastic netting as a mechanically stabilizing earth element to thereby provide a mechanically stabilized earth retaining wall construction. Using flexible plastic netting and smaller, specially constructed blocks arranged in rows superimposed one upon the other, reduces the necessity for large or heavy mechanical lifting equipment during the construction phase of such a wall. 
     Others have also suggested the utilization of facing blocks of various configurations with concrete anchoring and/or frictional netting material to build an embankment and wall. Among the various products of this type commercially available is a product offered by Rockwood Retaining Walls, Inc. of Rochester, Minn. and a product offered by Westblock Products, Inc. and sold under the trade name, Gravity Stone. Common features of these systems appear to be the utilization of various facing elements in combination with backfill, wherein the backfill is interactive with plastic or fabric reinforcing and/or anchoring means which are attached to the facing elements. Thus, there is a great diversity of such combinations available in the marketplace or disclosed in various patents and other references. 
     Nonetheless, there has remained the need to provide an improved system utilizing anchoring and/or frictional interaction of backfill and elements positioned in the backfill wherein the elements are cooperative with and attachable to facing elements, including blocks which are smaller and lighter than large facing panels such as utilized in many installations or with wire mesh facing elements. The present invention comprises an improved combination of elements of this general nature and provides enhanced versatility in the erection of retaining walls and embankments, as well as in the maintenance and cost of such structures. The present invention further comprises various stabilizing elements useful in the construction of such civil engineering structures. 
     SUMMARY OF THE INVENTION 
     Briefly, the present invention comprises a combination of components to provide an improved civil engineering structure including a retaining wall system or construction. The invention also comprises the components or elements from which the civil engineering structure is fabricated. A feature of the invention is a modular wall block which may be used as a facing component for a retaining wall construction. The modular wall block may be unreinforced and dry cast. The block includes a front face which is generally planar, but may be configured in almost any desired finish and shape. The wall block also includes generally converging side walls, generally parallel top and bottom surfaces, a back wall, vertical throughbores or passages through the block specially positioned to enhance the modular character of the block, and counterbores, associated with the throughbores, having a particular shape and configuration which permit the block to be integrated with and cooperative with various types of anchoring and/or earth stabilizing elements. Special corner block and cap block constructions are also disclosed. 
     Various earth stabilizing and/or anchor elements are also disclosed for cooperation with the modular wall or face block and other blocks or facing elements. An embodiment of the earth stabilizing and/or anchoring elements includes first and second generally parallel tensile rods which are designed to extend longitudinally from the modular wall block into compacted soil or an earthen work. The ends of the tensile rods are configured to fit within the counterbores defined in the top or bottom surface of the modular wall or facing block. Angled or transverse cross members connect the parallel tensile rods and are arrayed not only to enhance the anchoring characteristics, but also the frictional characteristics of interaction of the tensile rods with earth or particulate material comprising the civil engineering structure. Numerous alternative stabilizing elements are disclosed as well as various systems and components for attachment of the stabilizing elements to facing elements such as wall blocks, panels, and the like. 
     An alternative stabilizing element cooperative with the modular blocks comprises a harness which includes generally parallel tension arms that fit into the counterbores in the blocks and which cooperate with the vertical anchoring rods so as to attach the tension arms to the blocks. The harness includes a cross member connecting the opposite tension arms adjacent the back face outside of the modular block. The cross member of the harness may be cooperative with a geotextile strip, for example, which extends into the earthen work behind the modular wall block. Again, the harness cooperates with vertical anchoring rods which extend into the passages or throughbores defined in the modular blocks. 
     The described wall construction further includes generally vertical anchoring rods that interact both with the stabilizing elements and also with the described modular blocks by extending vertically through the throughbores in those blocks while simultaneously engaging the stabilizing elements. Various other alternative permutations, combinations and constructions of the described components are set forth. 
     Thus it is an object of the invention to provide an improved retaining wall construction comprised of modular blocks and cooperative stabilizing elements that project into an earthen work or particulate material. 
     It is a further object of the invention to provide an improved and unique modular block construction for utilization in the construction of a improved retaining wall construction. 
     Yet another object of the invention is to provide a modular block construction which may be easily fabricated utilizing known casting or molding techniques. 
     Yet a further object of the invention is to provide a substantially universal modular wall block which is useful in combination with earth retaining or stabilizing elements as well as anchoring elements. 
     Yet another object of the invention is to provide numerous unique earth anchoring and/or stabilizing elements that are cooperative with a modular wall or facing block or other facing elements. 
     Another object of the invention is to provide various stabilizing element designs and also various useful designs for components to attach stabilizing elements to facing elements. 
     Yet a further object of the invention is to provide a combination of components for manufacture of a retaining wall system or construction which is inexpensive, efficient, easy to use and which may be used in designs susceptible to conventional design or engineering techniques. 
     Another object of the invention is to provide a design for a modular block which may be used in a mechanically stabilized earth construction or an anchor wall construction wherein the block may be unreinforced and/or manufactured by dry cast or pre-cast methods, and/or interactive with rigid, metal stabilizing elements as well as flexible stabilizing elements such as geotextiles. 
     These and other objects, advantages and features of the invention will be set forth in the detailed description which follows. 
    
    
     BRIEF DESCRIPTION OF THE DRAWING 
     In the detailed description which follows, reference will be made to the drawing comprised of the following figures: 
     FIG. 1 is an isometric, cut away view of an embodiment and example of the modular block retaining wall construction of the invention incorporating various alternative elements or components; 
     FIG. 2 is an isometric view of the improved standard modular wall block utilized in the retaining wall construction of the invention; 
     FIG. 3 is an isometric view of an earthen stabilizing and/or anchor element which is used in combination with the modular block of FIG.  2  and which cooperates with and interacts with earth or particulate by means of friction and/or anchoring means or both; 
     FIG. 4 is an isometric view of a typical anchoring rod which interacts with the wall block of FIG.  2  and the earth stabilizing element of FIG. 3 in the construction of the improved retaining wall of the invention; 
     FIG. 4A is an alternate construction of the rod of FIG. 4; 
     FIG. 5 is a bottom plan view of the block of FIG. 2; 
     FIG. 6 is a rear elevation of the block of FIG. 5; 
     FIG. 7 is a side elevation of the block of FIG. 5; 
     FIG. 8 is a top plan view of a corner block as contrasted with the wall block of FIG. 5; 
     FIG. 9 is a rear elevation of the block of FIG. 8; 
     FIG. 10 is a side elevation of the block of FIG. 8; 
     FIG. 11 is a top plan view of an alternative corner block construction; 
     FIG. 12 is a rear elevation of the block of FIG. 11; 
     FIG. 13 is a side elevation of the block of FIG. 11; 
     FIG. 13A is a top plan view of an alternate throughbore pattern for a corner block; 
     FIG. 14 is a top plan view of a typical earth stabilizing element or component of the type depicted in FIG. 3; 
     FIG. 15 is a top plan view of a component of an alternative earth stabilizing element; 
     FIG. 15A is an isometric view of an alternative component for the element of FIG. 15; 
     FIG. 16 is a bottom plan view of the element shown in FIG. 14 in combination with a block of the tpe shown in FIG. 2; 
     FIG. 17 is a bottom plan view of the component or element depicted in FIG. 16 in combination with a flexible geotextile material and a block of the type shown in FIG. 2; 
     FIG. 18 is a front elevation of a typical assembly of the modular wall blocks of FIG.  2  and corner blocks such as shown in FIG. 8 in combination with the other components and elements forming a retaining wall; 
     FIG. 19 is a sectional view of the wall of FIG. 18 taken substantially along the line  19 — 19 ; 
     FIG. 20 is a sectional view of the wall of FIG. 18 taken along line  20 — 20  in FIG. 18; 
     FIG. 21 is a cross sectional view of the wall of FIG. 18 taken By along the line  21 — 21 ; 
     FIG. 22 is a side sectional view of a combination of the type depicted in FIG. 17; 
     FIG. 23 is a side sectional view of a combination of elements of the type depicted in FIG. 16; 
     FIG. 24 is a top plan view of a typical retaining wall construction depicting the arrangement of the modular block elements to form an outside curve; 
     FIG. 25 is a top plan view of modular block elements arranged so as to form an inside curve; 
     FIG. 26 is a front elevation depicting a typical retaining wall in accord with the invention; 
     FIG. 27 is an enlarged front elevation of a retaining wall illustrating the manner in which a slip joint may be constructed utilizing the invention; 
     FIG. 28 is a sectional view of the wall shown in FIG. 27 taken substantially along the lines  28 — 28 ; 
     FIG. 29 is a sectional view of the wall of FIG. 27 taken substantially along the line  29 — 29 ; 
     FIG. 30 is a bottom plan view of the modular facing block of the invention as it is initially dry cast in a mold for a pair of facing blocks; 
     FIG. 31 is a bottom plan view similar to FIG. 30 depicting the manner in which the cast blocks of FIG. 30 are separated to provide a pair of separate modular facing blocks; 
     FIG. 32 is a top plan view of the cast formation of the corner blocks; 
     FIG. 33 is a top plan view of the corner blocks of FIG. 32 after they have been split or separated; 
     FIG. 34 is a plan view of an alternative casting array for corner blocks; 
     FIG. 35 is a plan view of corner blocks of FIG. 24 separated; 
     FIG. 36 is a front elevation of a wall construction with a cap block; 
     FIG. 36A is a top plan view of cap blocks forming a corner; 
     FIG. 37 is an isometric view of an alternative stabilizing element; 
     FIG. 38 is a bottom plan view of an alternative stabilizing element and wall block construction; 
     FIG. 39 is a plan view of another alternative stabilizing element and wall block construction. 
     FIG. 40 is a side elevation of an alternative wall construction utilizing anchor type stabilizing elements; 
     FIG. 41 is a bottom plan view of the wall construction of FIG. 40 taken along the line  41 — 41 ; 
     FIG. 42 is a top plan view of an alternative stabilizing element construction; 
     FIG. 43 is a top plan view of another alternative stabilizing element construction; 
     FIG. 44 is a top plan view of another stabilizing element construction; 
     FIG. 45 is a bottom plan view of an alternative cap block construction; 
     FIG. 46 is a cross-sectional view of the alternative cap block construction of FIG. 45 taken along the line  46 — 46 ; 
     FIG. 47 is a side elevation of an alternative construction depicting a stabilizing element in combination with a precast wall panel and further illustrating a fastening assembly for fastening the stabilizing element to the panel; 
     FIG. 48 is a top plan view of an assembly similar to that of FIG. 47; 
     FIG. 49 is a side elevation of a further alternative assembly again similar to that of FIG. 47; 
     FIG. 50 is a side elevation of yet another assembly similar to that of FIG. 47 incorporating a further mechanism for attaching a stabilizing element to a panel, block or wall member; 
     FIG. 51 is a plan view of the fastener element utilized in combination with the assembly of FIG. 50; 
     FIG. 52 is a top plan view of certain component parts of FIG. 50 prior to assembly; 
     FIG. 53 is a side elevation of an assembly similar to that of FIG. 50 utilizing the substantially the same components assembled in a different configuration; 
     FIG. 54 is a side elevation of another stabilizing element construction in combination with a system for fastening the stabilizing element to a panel, a block or the like; 
     FIG. 55 is a top plan view of the assembly FIG. 54; 
     FIG. 56 is a top plan view of an alternative stabilizing element of the type that can be utilized in combination with the assembly of FIG.  54  and various other types of assemblies utilizing wall blocks, precast facing elements and other types of facing elements; 
     FIG. 57 is a side elevation of the stabilizing element of FIG. 56; 
     FIG. 58 is a perspective of a stabilizing element of the type depicted in FIG. 47, for example, and in combination with a wall panel and an alternative connector or tab construction cast in place in the wall panel; 
     FIG. 59 is an isometric view of the tab construction cast in place in the wall panel depicted in FIG. 58; 
     FIG. 60 is a side elevation of an alternative cast in place wall panel and tab construction; 
     FIG. 61 is a perspective view of an alternative stabilizing element configuration in combination with a cast in place fastening construction for attaching the stabilizing element to a wall panel and further for attaching segments or sections of stabilizing elements; and 
     FIG. 62 is a top plan view of the construction of FIG.  61 . 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     General Description 
     FIG. 1 generally depicts the combination of components or elements which define the modular block retaining wall construction of the invention. Modular blocks  40  are arranged in courses one upon the other in an overlapping array. Generally rigid earth retaining or stabilizing elements  42  and/or flexible stabilizing elements  44  are cooperative with or interact with the blocks  40 . Also, anchoring elements such as tie back elements may be utilized in cooperation with blocks  40 . The stabilizing or anchoring elements  42 ,  44  are attached to blocks  40  by means of vertical anchoring rods  46 . The elements  42  and/or  44  project from the back face of blocks  40  into compacted soil  48  and interact with the soil  48  as anchors and/or frictionally. 
     It is noted that interaction between the elements  42  and  44  and soil or particulate  48  depends ultimately upon frictional interaction of particulate material comprising the soil  48  with itself and with elements, such as elements  42  and  44 . Conventionally, that interaction may be viewed as an anchoring interaction in many instances rather than a frictional interaction. Thus, for purposes of the disclosure of the present invention, both frictional and anchoring types of interaction of compacted soil  48  with stabilizing and/or anchor elements are considered to be generally within the scope of the invention. 
     The invention comprises a combination of the described components including the blocks  40 , stabilizing elements  42  and/or  44 , anchoring rods  46  and soil  48  as well as the separate described components themselves, the method of assembly thereof, the method of manufacture of the separate components and various ancillary or alternative elements and their combination. Following is a description of these various components, combinations and methods. 
     Facing Block Construction 
     FIG. 2, as well as FIGS. 5 through 13,  13 A,  30  through  36 A,  44  and  45  illustrate in greater detail the construction of standard modular or facing blocks  40  and various other blocks. FIG. 2, as well as FIGS. 5 through 7, depict the basic modular block  40  which is associated with the invention. FIGS. 30 and 31 are also associated with the basic or standard modular block  40  in FIG.  2 . The remaining figures relate to other block constructions. 
     Standard Modular Block 
     As depicted in FIGS. 2 and 5 through  7 , the standard modular block  40  includes a generally planar front face  50 . The front face  50 , in its preferred embodiment, is typically aesthetically textured as a result of the manufacturing process. Texturing is, however, not a limiting characteristic of the front face  50 . The front face  50  may include a precast pattern. It may be convex or concave or some other desired cast or molded shape. Because the block  40  is manufactured principally by casting techniques, the variety of shapes and configurations, surface textures and the like for the front face  50  is not generally a limiting feature of the invention. 
     The front face  50 , however, does define the outline of the modular blocks comprising the wall as shown in FIG.  1 . Thus, the front face  50  defines a generally rectangular front elevation configuration, and because the blocks  40  are typically manufactured by means of casting techniques, the dimensions of the perimeter of front face  50  are typically those associated with a standard concrete block construction. The size or dimension, however, is not a limiting feature of the invention. 
     Spaced from and generally parallel to the front face  50  is a back face  52 . The back face  52  is connected to the front face  50  by means of side walls  54  and  56  which generally converge towards one another from the front face  50 . The convergence is generally uniform and equal on both sides of the block  40 . Convergence may commence from front edges  51 ,  53 , or may commence a distance from front face  50  toward back face  52 . Convergence may be defined by a single flat side surface or multiple flat or curved side surfaces. The convergence angle is generally in the range of 7° to 15° in the preferred embodiment of the invention, though, a range of convergence of 0° to about 30° is useful. 
     The thickness of the block  40 , or in other words the distance between the front face  50  and back face  52 , may be varied in accord with engineering and structural considerations. Again, typical dimensions associated with concrete block constructions are often relied upon by casters and those involved in precast or dry cast operations of block  40 . Thus, for example, if the dimensions of the front face  50  are 16 inches wide by 8 inches high, the width of the back face would be approximately 12 inches and the depth or distance between the faces  50 ,  52  would be approximately 8, 10 or 12 inches. 
     In the embodiment shown, the side walls  54  and  56  are also rectangular as is the back face  52 . Parallel top and bottom surfaces  58  and  60  each have a trapezoidal configuration and intersect the faces  50 ,  52  and walls  54 ,  56 . In the preferred embodiment, the surfaces  58 ,  60  are congruent and parallel to each other and are also at generally right angles with respect to the front face  50  and back face  52 . 
     The block  40  includes a first vertical passage or throughbore  62  and a second vertical passage or throughbore  64 . Throughbores  62 ,  64  are generally parallel to one another and extend between surfaces  58 ,  60 . As depicted in FIG. 5 the cross-sectional configurations of the throughbores  62  and  64  are preferably uniform along their length. The throughbores  62 ,  64  each include a centerline axis  66  and  68 , respectively. The cross-sectional shape of each of the throughbores  62  and  64  is substantially identical and comprises an elongated or elliptical configuration or shape. 
     Each of the throughbores  62  and  64  and, more particularly, the axis  66  and  68  thereof, is precisely positioned relative to the side edges  51  and  53  of the front face  50 . The side edges  51  and  53  are defined by the intersection respectively of the side wall  54  and front face  50  and side wall  56  and front face  50 . The axis  66  is one quarter of the distance between the side edge  53  and the side edge  51 . The axis  68  is one-quarter of the distance between the side edge  51  and the side edge  53 . Thus the axes  66  and  68  are arrayed or spaced one from the other by a distance equal to the sum of the distances that the axes  66 ,  68  are spaced from the side edges  51  and  53 . 
     The throughbores  62  and  64  are positioned intermediate the front face  50  and back face  52  approximately one quarter of the distance from the front face  50  toward the back face  52 , although this distance may be varied depending upon engineering and other structural considerations associated with the block  40 . As explained below, compressive forces on the block  40  result when an anchoring rod  46 , which fits within each one of the throughbores  62  and  64 , engages against a surface of each throughbore  62  or  64  most nearly adjacent the back face  52 . The force is generally a compressive fore on the material comprising the block  40 . Thus, it is necessary, from a structural analysis viewpoint, to ensure that the throughbores  62  and  64  are appropriately positioned to accommodate the compressive forces on block  40  in a manner which will maintain the integrity of the block  40 . 
     A counterbore  70  is provided with the throughbore  62 . Similarly, a counterbore  72  is provided with the throughbore  64 . Referring first to the counterbore  70 , the counterbore  70  is defined in the surface  58  and extends from back face  52  over and around the throughbore  62 . Importantly, the counterbore  70  defines a pathway between the throughbore  62  and the back face  52  wherein a tensile member (described below) may be placed in a manner such that the tensile member may remain generally perpendicular to an element, such as rod  46 , positioned in the throughbore  62 . 
     In a similar fashion, the counterbore  72  extends from the back face  52  in the surface  58  and around the throughbore  64 . In the preferred embodiment, the counterbores  70  and  72  are provided in the top face  58  uniformly for all of the blocks  40 . However, it is possible to provide the counterbores in the bottom face  60  or in both faces  58  and  60 . Note that since the blocks  40  may be inverted, the faces  58  and  60  may be inverted between a top and bottom position. In sum, the counterbores  70  and  72  are aligned with and constitute counterbores for the throughbores  62  and  64 , respectively. 
     In the preferred embodiment, a rectangular cross-section passage  74  extends parallel to the throughbores  62  and  64  through the block  40  from the top surface  58  to the bottom surface  60 . The passage  74  is provided to eliminate weight and bulk of the block  40  without reducing the structural integrity of the block. It also provides a transverse counterbore connecting counterbores  70  and  72 . The passage  74  is not necessarily required in the block  40 . The particular configuration and orientation, shape and extent of the passage  74  may be varied considerably in order to eliminate bulk and material from the block  40 . 
     The general cross-section of the throughbores  62  and  64  may be varied. Importantly, it is appropriate and preferred that the cross-sectional shape of the throughbores  62  and  64  permits lateral movement of the block  40  relative to anchoring rods  46 , for example, which are inserted in the throughbores  62  and  64 . Thus, the dimension of the throughbores  62  and  64  in the direction parallel to the back face  52  in the embodiment shown is chosen so as to be greater than the diameter of a rod  46 . The transverse (or front to back) dimension of the throughbores  62  and  64  more closely approximates the diameter of the rod  46  so that the blocks  40  will not be movable from front to back into and out of a position. That is, the front face  50  of each of the blocks  40  in separate courses and on top of each other can be maintained in alignment because of the size and configuration of throughbores  62 ,  64 . Consequently, the blocks  40  can be preferably adjusted from side to side as one builds a wall of the type depicted in FIG. 1, though the blocks  40  are not adjustable inwardly or outwardly to any great extent. This maintains the planar integrity of the assembly comprising the retaining wall so that the blocks  40  will be maintained in a desired and generally planar array. Side to side adjustment insures that any gap between the blocks  40  is maintained at a minimum and also permits, as will be explained below, various adjustments such as required for formation of inside and outside curvature of the wall construction. 
     The depth of the counterbores  70  and  72  is variable. It is preferred that the depth be at least adequate to permit the elements  42  and/or  44  to be below or no higher than the level of surface  58 , so that when an additional course of blocks  40  is laid upon a lower course of blocks  40 , the elements  42  and/or  44  are appropriately and properly recessed so as not to interfere with an upper course of blocks  40 . 
     Referring briefly to FIGS. 30 and 31, there is illustrated a manner in which the standard modular blocks of FIGS. 2 and 5 can be manufactured. Typically, such blocks may be cast in pairs using dry casting techniques with the front face of the blocks  40  cast in opposition to each other with a split line such as split line  75  as depicted in FIG.  30 . Then after the blocks  40  are cast, a wedge or shear may be utilized to split or separate blocks  40  one from the other revealing a textured face such as illustrated in FIG.  31 . Appropriate drag and draft angles are incorporated in the molds with respect to such a casting operation as will be understood by those of ordinary skill in the art. Also note, the dry cast blocks  40  are not typically reinforced. However, the dry cast blocks may include reinforcing fibers. Lack of reinforcement and manufacture by dry casting techniques of a block  40  for use with metallic and/or generally rigid stabilizing elements is not known to be depicted or used in the prior art. 
     Corner and/or Split Face Blocks 
     FIGS. 8 through 13A, and  32  through  36 A depict blocks that are used to form corners and/or caps of the improved retaining wall construction of the invention or to define a boundary or split face in such a retaining wall. FIGS. 8,  9  and  10  disclose a first corner block  80  which is similar to, but dimensionally different from the corner blocks of FIGS. 11,  12  and  13  and the corner block  110  of FIG.  13 A. 
     Referring, therefore, to FIGS. 8,  9  and  10 , corner block  80  comprises a front face  82 , a back face  84 , a finished side surface  86  and a unfinished side surface  88 . A top surface  90  is parallel to a bottom surface  92 . The surfaces and faces generally define a rectangular parallelpiped. The front face  82  and the finished side surface  86  are generally planar and may be finished with a texture, color, composition and configuration which is compatible with or identical to the surface treatment of blocks  40 . The corner block  80  includes a first throughbore  94  which extends from the top surface  90  through the bottom surface  92 . The throughbore  94  is generally cylindrical in shape; however, the throughbore  94  may include a funnel shaped or frusto-conical section  96  which facilitates cooperation with a rod, such as rod  46 , as will be explained below. 
     The cross-sectional area of the throughbore  94  is slightly larger than the cross-sectional area and configuration of a compatible rod, such as rod  46 , which is designed to fit through the throughbore  94 . Importantly, the cross-sectional shape of the throughbore  94  and the associated rod, such as rod  46 , are generally congruent to preclude any significant alteration and orientation of a positioned corner block  80  once a rod  46  is inserted through a throughbore  94 . 
     The position of the first throughbore  94  relative to the surfaces  82 ,  84  and  86  is an important factor in the design of the corner block  80 . That is, the throughbore  94  includes a centerline axis  98 . The axis  98  is substantially an equal distance from each of the surfaces  82 ,  84  and  86 , thus rendering the distances x, y and z in FIG. 8 substantially equal, where x is the distance between the axis  98  and the surface  82 , y is the distance between the axis  98  and the surface  84 , and z is the distance between the axis  98  and the surface  86 . 
     The corner block  80  further includes a second throughbore  100  which extends from the top surface  90  through the bottom surface  92 . The second throughbore  100  may also include a funnel shaped or frusto-conical section  104 . The cross-sectional shape of the throughbore  100  generally has an elongated or elliptical form and has a generally central axis  102  which is parallel to the surfaces  82 ,  84 ,  86  and  88 . The longitudinal dimension of the cross-sectional configuration of the second throughbore  100  is generally parallel to the front face  82 . The axis  102  is specially positioned relative to the side surface  88  and the front face  82 . Thus the axis  102  is positioned a distance w from the front face  82  which is substantially equal to the distance w which axis  66  is positioned from front face  50  of the block  40  as depicted in FIG.  5 . The axis  102  is also positioned a distance v from the unfinished side surface  88  which is substantially equal to the distance c which the axis  62  is positioned from the edge  53  of the front face  50  of the block  40  as depicted again in FIG. 5. A counterbore  103  may be provided for throughbore  100 . Counterbore  103  extends from back surface  84  and around bore  100 . The countterbore  103  may be provided in both top and bottom surfaces  90  and  92 . 
     The distance u between the axis  102  and the axis  98  for the corner block  80  is depicted in FIG.  8  and is equal to the distance u between the axis  66  and the axis  68  for the block  40  in FIG.  5 . The distance u is substantially two times the distance v. The distance v between the axis  102  and the side surface  88  is substantially equal to the distance z between the axis  98  and the side surface  86 . The correlation of the various ratios of the distances for the various blocks  40 ,  80  and  110  set forth above is summarized in the following Table No. 1: 
     
       
         
           
               
               
               
             
               
                   
                 TABLE 1 
               
               
                   
                   
               
             
            
               
                   
                 For Block 40 
                 2v = u 
               
               
                   
                 For Corner Block 80 
                 x = y = z 
               
               
                   
                   
                 x + y = u 
               
               
                   
                   
                 v + z = u 
               
               
                   
                 For Corner Block 110 
                 a = b = c 
               
               
                   
                   
                 d = v + c 
               
               
                   
                   
               
            
           
         
       
     
     It is to be noted that the corner block  80  of FIGS. 8,  9  and  10  is a corner block  80  wherein the perimeter of the front face  82  is dimensionally substantially a to the front face  50  of the block  40 . FIGS. 11,  12  and  13  illustrate an alternative corner block construction wherein the front face and finished side face or surface are different dimensionally from that of the corner block  80  in FIGS. 8,  9  and  10 . 
     Referring therefore to FIGS. 11,  12  and  13 , a corner block  110  includes a front face  112 , a back face  114 , a finished side surface  116 , an unfinished side surface  118 , top and bottom parallel surfaces  120  and  122 . The block  110  has a rectangular, parallelpiped configuration like the block  80 . The block  110  includes a first throughbore  124 , having a shape and configuration substantially identical to that of the first throughbore  94  previously described including the frusto-conical section  126 , and an axis  128 . Similarly, the block  110  includes a second throughbore  130  having an axis  132  with a cross-sectional configuration substantially identical to that of the second throughbore  100  and also including a frusto-conical or funnel shaped section  134 . Also, counterbores  131  may be provided in the top and bottom surfaces  120 ,  122 . The front face  112  and finished side surface  116  are finished, as previously described with respect to front face  50 , in any desired fashion. The front face  112  has a height dimension as illustrated in FIG. 13 as height h which is substantially equal to the height h of the block  40  in FIG. 7, as well as the height h of the block  80  as illustrated in FIG.  10 . 
     The axis  128  is again equally spaced from the face  112 , surface  116  and surface  114  as illustrated in FIG.  11 . Thus, th distance a from the surface  112  to axis  128  equals the distance b from the face  114  to the axis  128  which also equals the distance c from the surface  116  to the axis  128 . The axis  132  is spaced from the front face  112  by the distance w which again is equal to the distance w of spacing of axis  66  from face  50  of block  40  as shown in FIG.  5 . Similarly, the axis  132  is spaced a distance v from the unfinished side surface  118  which is equal to the distance c associated with the block  40  as depicted in FIG.  5 . The distance between the axis  132  and the axis  128  represented by d in FIG. 11 equals the distance v between axis  132  and surface  118  plus distance C, the distance between axis  128  and finished side surface  116 . Again, these dimensional relationships are set forth in Table 1. 
     FIG. 13A illustrates the configuration of a corner block which is reversible and includes throughbores  99 ,  101  which are shaped with an L shaped cross section so as to function as though they are a combination of throughbores  124 ,  130  of the embodiment of FIG.  11 . Thus, bores  99  and  101  each include an axis  128   a  which is equivalent to axis  128  of the corner block of FIG. 11 and a second axis  132   a  which is equivalent to the axis  132  of the block of FIG.  11 . 
     Other alternative block constructions are possible within the scope of the invention and some modifications and alternatives are discussed below. However, the aforedescribed block  40  as well as the corner blocks  80  and  110  are principal modular blocks to practice the preferred embodiment of the invention. 
     Stabilizing Elements 
     The second major component of the retaining wall construction comprises retaining elements which are interactive with and cooperate with the blocks  40 ,  80 , and  110 , particularly the basic block  40 . FIGS. 14 through 17 illustrate various stabilizing elements. Referring first to FIG. 14, there is illustrated a stabilizing element  42  which is comprised of a first parallel reinforcing bar  140  and a second parallel reinforcing bar  142 . The bars  140  and  142  each have a loop  144  and  146  respectively formed at an inner end thereof. Typically, the bars  140  and  142  are deformed to form the loops  144 ,  146  and the ends of the loops  144 ,  146  are welded back onto the bar  140  and  142 . 
     Importantly, each loop  144  and  146  is connected to a tension arm  148  and  150  defined by the bars  140  and  142 . The tension arms  148  and  150  are parallel to one another and are of such a length so as to extend beyond the back face of any of the blocks previously described. A cross member  152 , positioned beyond the back face of the block  40 , connects the arms  148  and  150  to ensure their appropriate spacing and alignment. A second cross member  154  ensures that the arms  148  and  150 , as well as the bars  140  and  142 , remain generally parallel. 
     There are additional cross members  156  provided along the length of the bars  140  and  142 . The spacing of the cross members  156  is preferably generally uniform along the outer ends of the bars  140  and  142 . The uniformly spaced cross members  156  are associated with the passive or resistive zone of a mechanically stabilized earth structure as will be described in further detail below. The cross members  156  are thus preferably uniformly spaced one from the other at generally closer intervals in the so called passive or resistive zone. However, this is not a limiting feature and uniform spacing may be preferred by a wall engineer. The bars or cross members  154 , as well as cross member  152 , are not necessarily closely spaced or even required so long as the bars  140  and  142  are maintained in a substantially parallel array. 
     It is noted that in the preferred embodiment, that just two bars  140  and  142  are required or are provided. However, stabilizing elements having one or more longitudinal members (e.g. bars  140 ,  142 ) may be utilized. The stabilizing element depicted and described with respect to FIG. 14 relies upon frictional interaction but could be configured to rely, as well, upon anchoring interaction with compacted soil. The cross members  156 , thus, could be configured to act as a collection of anchors. The bars  140  and  142  and cross members  156  in the preferred embodiment provide frictional interaction with compacted soil. 
     FIG. 15 illustrates a component of a further alternative stabilizing element  44 . Specifically referring to FIG. 15, the element depicted includes a harness or connector  160  which includes a first tension bar or arm  162  and a second bar or arm  164 . Arms  162  and  164  are generally parallel to one another and are connected by a cross member  166 , which in this case also includes a cylindrical, tubular member  168  retained thereon. Alternatively, as depicted in FIG. 15A, a C-shaped clamp member  167  may be fitted over the cross member  166 . 
     Each of the parallel tension arms  162  and  164  terminate with a loop  170  and  172 . The loops  170  and  172  are arranged in opposed relationship and aligned with one another as depicted in FIG.  15 . The ends of the loops  170  and  172  are welded at welds  174  and  176 , respectively to the arms  162  and  164 , respectively. 
     The harness or connector  160  is cooperative with the blocks, most particularly block  40 , as will be described in further detail. That detail is illustrated, in part, in FIGS. 16 and 17. Referring first to FIG. 16, there is depicted a stabilizing element  42 . FIG. 17 illustrates the stabilizing element  44 . Referring to FIG. 16 the element  42  and more particularly the tension arms  148  and  150  are positioned in the counterbores  70  and  72  of block  40  with the loops  144  and  146  positioned over the throughbores  64  and  62 , respectively. 
     Referring to FIG. 17, the connector  160 , which comprises a portion of the stabilizing element  44 , includes arms  162  and  164  which are fitted into the counterbores  70  and  72 , respectively of block  40  with loops  170  and  172 , respectively fitted over the throughbores  62  and  64 . Note that connector  160  is sufficiently recessed within the block  40  so as to be below the plane of the top surface  58  thereof. Similarly, the tension arms  148  and  150  of the element  42  are sufficiently recessed within the counterbores  70  and  72  to be below the plane or no higher than the plane of the top surface  58  of the block  40 . 
     Referring again to FIG. 17, the element  44  further includes a geotextile material comprising a lattice of polymeric strips, such as strip  180 , which is generally flexible and wherein an elongated length thereof is wrapped around or fitted over the tube or cylinder  168  or clamp  167  so that the opposite ends of the strips  180  extend outwardly and away from the block  40 . Thus, FIG. 16 illustrates a generally rigid element. FIG. 17 illustrates a generally flexible element. In each event, the elements  42  and  44  are cooperative with a block  40  as described. 
     Connectors 
     Depicted in FIG. 4 is a typical connector which comprises a reinforcing rod or bar, normally a steel reinforcing bar  46 , which is generally cylindrical in shape and which is fitted through loops, for example loops  170  and  172  in FIG.  17  and associated throughbores  62  and  64  of block  40  to thereby serve to retain the element  44  and more particularly the connector  160  cooperatively engaged with block  40 . The rod  46 , which is depicted as the preferred embodiment, is cylindrical as previously mentioned. However, any desired size may be utilized. It is to be noted that the steel reinforcing bars, which are recommended in order to practice the invention, are also utilized in cooperation with the specially configured first throughbores  94 ,  124  of the corner blocks  80 ,  110 . For example first throughbore  124  of the corner block  110  illustrated in FIG. 12 cooperates with a rod such as rod  46  illustrated in FIG.  4 . The rods  46  are of a sufficient length so that they will project through at least two adjacent blocks  40  which are stacked one on top of the other thus distributing the compressive forces resulting from the elements  44  interacting with the blocks  40  to blocks of adjacent courses forming a wall. 
     As depicted in FIG. 4A, the rod  46  may include a small stop or cross bar  47  welded or attached at its midpoint. Cross bar  47  insures that the rod  46  will be positioned properly and retained in position to engage blocks  40  above and below the block  40  in which rod  46  is positioned to cooperate with elements  42 ,  44 . Thus, the rod  46  will not fall or slip downward into throughbores  62 ,  64 . 
     Retaining Wall System 
     FIGS. 18 through 29 illustrate the manner of assembly of the components heretofore described to provide a retaining wall. Referring first to FIG. 18, there is depicted an array of three courses of modular blocks  40  and corner blocks  80  to define a section or portion of a wall using the components of the invention. Note that each of the courses provide that the blocks  40  are overlapping. Note further that the front face dimensions of the corner block  80  are equal to the front face dimensions of the modular blocks  40 . The side face or surface dimensions of the corner blocks  80  are equal to one half of the dimensions of the basic blocks  40 . 
     FIG. 19, which is a sectional view of the wall of FIG. 18, illustrates the manner of positioning the corner blocks  80  and modular basic building blocks  40  with respect to each other to define the first course of the wall depicted in FIG.  18 . Note that elements  42 , which are the rigid stabilizing elements, are cooperatively positioned for interaction with the blocks  40 . In the preferred embodiment, stabilizing elements  42  are provided for use in association with each and every one of the modular blocks  40  and the elements  42  include only two parallel reinforcing bars. It is possible to provide for constructions which would have a multiple number of reinforcing bars or special anchoring elements attached to the bars. The preferred embodiment is to use just two bars in order to conserve with respect to cost, and further, the two bar construction provides for efficient distribution of tensile forces and anchoring forces on the element  42 , and torsional forces are significantly reduced. 
     FIG. 20 illustrates the manner in which the corner block  80  may be positioned in order to define an edge or corner of the wall depicted in FIG.  18 . Thus, the block  80 , which is a very symmetrical block as previously described, may be alternated between positions shown in FIGS. 19 and 20. Moreover, the corner blocks  80  may be further oriented as depicted and described with respect to FIGS. 27 through 29 below. The element  44 , which is a stabilizing element utilizing a flexible polymeric or geotextile material, is depicted as being used with respect to the course or layer of blocks  40  defining or depicted in FIG.  20 . 
     FIG. 21 is a side sectional view of the wall construction of FIG.  18 . It is to be noted that the wall is designed so that the cross elements  156  are retained in the so-called resistive zone associated with such mechanically stabilized earth structure. As known to those of ordinary skill in the art, construction of such walls and the analysis thereof calls for the defining of a resistive zone  190  and an active zone  192 . The elements  42  are designed so that the cross members  156  are preferably more numerous in the resistive zone thus improving the efficiency of the anchoring features associated with the elements  42 . However, this is not a limiting feature. FIG. 21 illustrates also the use of the polymeric grid material  180 . It is to be noted that all of the elements  42  and/or  44  arm retained in a compacted soil or compacted earth in a manner described in the previously Fen prior art patents. Reference is made to the American Association of State Highway and Transportation Officials “Standard Specification for Highway Bridges”, Fourteenth Edition as amended (1990, 1991) and incorporated herewith by reference, for an explanation of design calculation procedures applicable for such constructions. 
     In FIG. 21, there is illustrated the placement of a stabilizing element, such as elements  42  or  44 , in association with each and every course of blocks  40 ,  80 . In actual practice, however, the stabilizing elements  42  and/or  44  may be utilized in association with separate layers or courses, e.g. every second, third or fourth course of blocks  40 ,  80  and/or at separate blocks, eg. every second or third block horizontally in accord with good design principles. This does not, however, preclude utilization of the stabilizing elements  42 ,  44  in association with each and every course and each and every block  40 ,  80 . Thus, it has been found that the mechanically stabilized earth reinforcement does not necessarily require stabilizing elements at every possible block position. Again, calculations with respect to this can be provided using techniques known to those of ordinary skill in the art such as referenced herein. 
     During construction, a course of blocks  40  are initially positioned in a line on a desired footing  200 , which may consist of granular fill, earthen fill, concrete or other leveling material. Earthen backfill material  202  is then placed behind the blocks  40 . An element, such as stabilizing element  42 , may then be positioned in the special counterbores  70 ,  72  in a manner previously described and defined in the blocks  40 ,  80 . Rods  46  may then be inserted to maintain the elements  42  in position with respect to the blocks  40 . The rods  46  should, as previously described, interact with at least two adjacent courses of blocks  40 . A layer of sealant, fabric or other material (not shown) may be placed on the blocks. Subsequently, a further layer of blocks  40  is positioned onto the rods  46 . Additional soil or backfill  202  is placed behind the blocks  40 , and the process continues as the wall is erected. In practice, it has been found preferable to orient the counterbores  70 ,  72  facing downward rather than upward during construction. This orientation facilitates keeping the counterbores  70 ,  72  free of debris, etc. during construction. 
     FIGS. 22 and 23 illustrate side elevations of the construction utilizing a flexible stabilizing element  44  in FIG. 22 and a rigid stabilizing element  42  in FIG.  23 . In each instance, the elements  42  and/or  44  are cooperative with blocks  40 , rods  46  and compacted soil  202  as previously described. 
     Referring next to FIGS. 24 and 25, as previously noted, the throughbores  62 ,  64  in the blocks  40  have an elongated cross-sectional configuration. Such elongation permits a slight adjustable movement of the blocks  40  laterally with respect to each other to ensure that any tolerances associated with the manufacture of the blocks  40  are accommodated. It was further noted that the blocks  40  are defined to include converging side surfaces  54 ,  56 . Because the side surfaces  54 ,  56  are converging, it is possible to form a wall having an outside curve as depicted in FIG. 24 or an inside curve as depicted in FIG.  25 . In each instance, the mode of assembly and the cooperative interaction of the stabilizing elements  42 ,  44  and rods  46  as well as blocks  40  are substantially as previously described with respect to a wall having a flat front surface. 
     FIG. 26 illustrates the versatility of the construction of the present invention. Walls of various shapes, dimensions and heights may be constructed. It is to be noted that with the combination of the present invention the front face of the wall may be substantially planar and may rise substantially vertically from a footing. Though it is possible to set back the wall or tilt the he wall as it ascends, that requirement is not necessary with the retaining wall system of the present invention. Also, the footing may be tiered. Also, the block  40  may be dry cast and is useful in combination with a rigid stabilizing element, such as element  42 , as contrasted with geotextile materials. 
     FIGS. 27,  28  and  29  illustrate the utilization of corner blocks to provide for a slip joint in a conventional wall of the type depicted in FIG.  26 . As shown in FIG. 27, a slip joint or vertical slot  210  is defined between wall sections  212  and  214 . Sectional views of the walls  212  and  214  are depicted in FIGS. 28 and 29. There it will be seen that the corner blocks  80 , which may be turned in either a right handed or left handed direction, may be spaced from one another or positioned as closely adjacent as desired or required. A fabric or other flexible material  216  may be positioned along the back side of the blocks  80  and then backfill  202  positioned against the flexible material  216 . 
     FIG. 29 illustrates the arrangement of these elements including the flexible barrier  216  and the blocks  80  for the next course of materials. It is to be noted that the first throughbore  94  of the corner blocks  80  as well as for the corner block  110  always align vertically over one another as each of the courses are laid. Thus, a rod  46  may be passed directly through the first throughbores  94  to form a rigidly held corner which does not include the capacity for adjustment which is built into the throughbores  62 ,  64  associated with the blocks  40  or the second throughbore  100  associated with corner blocks  80 . The positioning of the throughbores  94  facilitates the described assembly. The blocks  80  may include a molded split line  81  during manufacture. The line  81  facilitates fracture of the block  80  and removal of the inside half  83  as shown in FIG.  28 . 
     FIGS. 32,  33  and  34  illustrate a possible method for casting corner blocks  80 . Corner blocks  80  may be cast in an assembly comprising four corner blocks wherein the mold provides that the faces  82 ,  85  of the corner blocks  80  will be in opposition along split lines  182 ,  185  so that, as depicted in FIG. 32, four corner blocks  80  may be simultaneously cast, or as shown in FIG. 34, two corner blocks  80  may be cast. Then as depicted in FIG. 33, the corner blocks may be split from one another along the molded split lines to provide four (or two) corner blocks  80 . 
     The stabilizing elements  42 ,  44 , may also be cooperative with the counterbores  103 ,  131  of the corner blocks  80 ,  110 . In practice, such construction is suggested to stabilize corners of a wall. The elements  42 ,  44  would thus simultaneously cooperate with counterbores  103 ,  131  of a corner block  80 ,  110  and counterbores  70  or  72  of a modular block  40 . 
     The described components and the mode of assembly of those components constitutes a preferred embodiment of the invention. It is to be noted that the corner blocks  80  as well as the standard modular blocks  40  may be combined in a retaining wall having various types of stabilizing elements and utilizing various types of analysis in calculating the bill of materials. That is, the stabilizing elements have both anchoring capabilities as well as frictional interactive capabilities with compacted soil or the like. Thus, there is a great variety of stabilizing elements beyond those specifically described which are useful in combination with the invention. 
     For example, the stabilizing elements may comprise a mat of reinforcing bars comprised of two or more parallel bars which are designed to extend into compacted soil. Rather than forming the loops on the ends of those bars to interact with vertical rods  46 , it is possible to merely bend the ends of such rods at a right angle so that they will fit into the throughbores  62 ,  64  through the blocks  40  thereby holding mats or reinforcing bars in position. Additionally, the rods  46  may be directly welded to longitudinal tensile arms in the throughbores, thus, eliminating the necessity of forming a loop in the ends of the tension arms. 
     Though two tensions arms and thus two reinforcing bars are the preferred embodiment, a multiplicity of tension arms may be utilized. Additionally, as pointed out in the description above, the relative size of the corner blocks may be varied and the dimensional alternatives in that regard were described. The shapes of the rods  46  may be varied. The attachment to the rods  46  may be varied. 
     Also, cap blocks  250  may be provided as illustrated in FIG. 35 and 36. Such blocks  250  could have a plan profile like that of modular blocks  40  but with a longer lateral dimension and four throughbores  252 , which could be aligned in pairs with throughbores  62 ,  64 . The cap blocks  250  may then be alternated in orientation, as depicted in FIG. 35, with rods  46  fitting in proper pairs of openings  252 . Mortar in openings  252  would lock the cap blocks  250  in place. Cap blocks  250  could also be split into halves  254 ,  256 , as shown in FIG. 35, to form a corner. An alternative cap block construction comprises a rectangular shaped cap with a longitudinal slot on the underside for receipt of the ends of rods  46  projecting from the top course of a row of blocks  40 . Other constructions are also possible. 
     Another alternative construction for a stabilizing element is illustrated in FIG.  37 . There, tension arms  260 ,  262  and cross members  264  cooperate with a clamp  266  which receives a bolt  268  to retain a metal strip  270 . Strip  270  is designed to act as a friction strip or connect to an anchor (not shown). 
     FIG. 38 depicts another alternative construction for a stabilizing element  280  and the connection thereof to block  40 . Element  280  includes parallel tension arms  281 ,  283  with a cross member  282  which fits in the space between counterbores  70 ,  72  defied by page  74 . The shape of the walls defining the passage  74  may thus be molded to maximize the efficient interaction of the stabilizing element  280  and block  40 . 
     FIG. 39 depicts yet another alternative construction wherein block  40  includes a passage  290  from internal passage  74  through the back face  52  of block  40 . A stabilizing element such as a strip  292  fits through passage  290  and is retained by a pin  294  through an opening in strip  292 . Strip  292  may be tied to an anchor (not shown) or may be a friction strip. Rods  46  still are utilized to join blocks  40 . 
     FIGS. 40 and 41 depict a wall construction comprised of blocks  40  in combination with anchor type stabilizing elements. The anchor type stabilizing elements are, in turn, comprised of double ended tensile elements  300  analogous to elements  42  previously described. The elements  300  are fastened to blocks  40  at each end by means of vertical rods  46 . The blocks  40  form an outer wall  302  and an inner anchor  304  connected by elements  300 . Anchors  304  are imbedded in compacted soil  305 . The inside surface of the outer wall  302  may be lined with a fabric liner  306  to prevent soil erosion. This design for a wall construction utilizes the basic components previously described and may have certain advantages especially for low wall constructions. 
     FIGS. 42,  43  and  44  illustrate further alternative constructions for a stabilizing element  302  and a connection thereof to block  40 . Reference is also directed to FIG. 38 which is related functionally to FIGS. 42,  43 , and  44 . Referring to FIG. 42, there is depicted a block  40  with a stabilizing element  302  comprised of first and second parallel arms  304  and  305  which are formed from a continuous reinforcing bar to thereby define an end loop  306  which fits over a formed rib  308  defined between the connected counterbores  70  and  72 . This is analogous to the construction depicted in FIG.  38 . The parallel arms or bars  304  and  305  are connected one to the other by cross members  307  and  309  which are connected to the arms  304  and  305  at an angle to thereby define a truss type construction. The ends of the arms  304  and  305  may be connected by a transverse, perpendicular cross member or cross brace  310 . 
     Referring to FIG. 43, there is illustrated yet another alternative construction wherein a stabilizing element  312  is again comprised of parallel arms  314  and  316  which form a symmetrical closed loop construction including an end  318  having a generally V shape as depicted in FIG. 43 cooperative with a rib  320  defied in the block  40 . Note that the cross members  322  are at an angle to define a truss type configuration. Further note that the V-shaped end  318  includes an opposite end counterpart  328  so that the entire stabilizing element  312  is generally symmetrical. It may or may not be symmetrical, depending upon desires. 
     FIG. 44 illustrates a variation on the theme of FIG. 43 wherein a stabilizing element  324  is comprised of arms  326  and  328  which cooperate with reinforcing bars  46  positioned in block  40  in the manner previously described. Crossing members  328  are again configured to define a generally truss shaped pattern analogous to the construction shown in FIGS. 42 and 43. Thus it can be seen that the construction of the stabilizing element may be varied significantly while still providing a rather rigid stabilizing element cooperative with blocks  40  and corner blocks as previously described. 
     FIGS. 45 and 46 illustrate an alternative to the cap block construction previously described. In FIG. 45, the bottom plan view of the cap block has substantially the same configuration as a face block  40 . Thus cap block  340  includes counterbores  70  and  72  which are designed to be cooperative with stabilizing elements in the manner previously described. The passageways through the cap block  340 , however, do not pass entirely through the block. Thus, as illustrated in FIG. 46, the cap block  340  includes counterbores  72  and  70  as previously described. A passageway for the reinforcing bars  46 ; namely, passage  342  and  344  extends only partially through the block  340 . Similarly, the passage  346  extends only partially through the cap block  340 . In this manner, the cap block  340  will define a cap that does not have any openings at the top thereof. The cap block  340  as depicted in FIGS. 45 and 46 may, when in a position on the top of the wall, have gaps between the sides of the blocks because of their tapered shape. Thus it may be appropriate and desirable to mold or cast the cap blocks in a rectangular, parallelpiped configuration as illustrated in dotted lines in FIG.  45 . Alternatively, the space between the blocks  340  forming the cap may be filled with mortar or earthen fill or other fill. 
     Alternative Stabilizing Elements and Combinations 
     Referring to FIG. 47, an alternative stabilizing element is depicted in combination with a precast wall panel. Specifically a stabilizing element  400 , which is similar to such elements previously disclosed, includes a first horizontal run  402  and a second, coplanar, horizontal parallel run  404 . Runs  402 ,  404  are spaced from one another by means of a crossbar  406  welded thereto. A series of cross bars  406  at spaced intervals are provided as with the construction of stabilizing elements previously described. Inner ends  408  and  409  of the stabilizing element  400  are formed as closed loops  410  and  412 , again, as previously disclosed. These loops  410 ,  412 , however, are positioned one over the other so that they define a vertical passage or opening  414 . Thus the runs  402 ,  404  are bent toward one another so that loops  410 ,  412  overlie one another to define the opening  414 . 
     A precast panel or block member or the like such as panel  416 , includes a cast-in-place connecting member  418  projecting from the backside thereof as projecting tabs  420  and  422  having aligned, vertical passageways  424  and  426  therethrough. The passage or opening  414  associated with the looped ends  410  and  412  is aligned with the passageways  424  and  426 . A bolt  428  is then vertically inserted through the aligned passage  414  and passageways  424 ,  426 , and a nut  430  is attached to the threaded end of bolt  428 . Washers, such as washers  432 , may be positioned on bolt  428 , as depicted, in order to ensure that the bolt  428  and nut  430  will not accidentally fall through the passage  414  or passageways,  424 ,  426 . Attachment of the stabilizing element  400  to the member  418  is thus effected. 
     This same stabilizing element  400  may be attached to a strip or element such as an element  266  in FIG. 37 extending from a block  40  of the type previously described as in FIG.  2 . Thus stabilizing element may be utilized in combination with a myriad of fading elements, including but not limited to, precast panels, blocks, wire grids and other facing elements. 
     Referring to FIG. 48, another alternative configuration of a stabilizing element is depicted. In FIG. 48, a stabilizing element  452  includes spaced generally parallel horizontal runs or rebars  454  and  456 . The runs  454 ,  456  are spaced from one another and connected together by spaced generally parallel, horizontal cross members  458 ,  460  and  462 . The cross members of  458 ,  460  and  462  are typically rods or reinforcing bars and are welded to the horizontal bars or longitudinal bars  454  and  456 . The cross bars, such as cross bar  458 , may extend laterally beyond the longitudinal bars  454  and  456 , thereby defining projecting ends such as ends  464  and  466  in FIG.  48 . The runs  454  and  456  connect or otherwise constitute a single, connected, reinforcing bar which defines a loop  468 . The loop  468  in FIG. 48 is defined by the reinforcing bar which is bent and crosses over itself as depicted in FIG.  48 . It is possible, however, to have the loop  468  open ended, i.e., parallel runs  454 ,  456  connected by a crown or cross member. 
     The stabilizing element  452  is attached to a panel  470  having a cast in place connecting element  472  and one or more projecting tabs  474  in a manner similar to the connection construction in the embodiment depicted in FIG.  47 . Thus, a bolt  476  co-acts with one or more of the tabs or elements  474 . Also, the stabilizing element  452  of FIG. 48 may be utilized in combination with a strip or element such as element  266  in FIG. 37 for cooperative engagement with a block  40  of the type described and depicted in FIG.  2 . 
     FIG. 49 depicts another alternative or variant of the embodiment disclosed in FIG.  47 . Referring to FIG. 49, the stabilizing element  400  is designed with the looped ends  410  and  412  abutting or adjacent to one another so that the bolt  428  and cooperative nut  430  may be fitted through the tabs  420  and  422  and ends  410 ,  412  retained between those tabs  420  and  422 . Alignment of the looped ends  410  and  412  and co-action thereof with the bolt  428  and nut  430  is somewhat simplified by this arrangement relative to that of FIG. 47 inasmuch as the tabs  420  and  422  assume the role of the washers such as the washers  432  in FIG.  47 . Fewer parts are required for the preferred embodiment of this assembly. 
     FIGS. 50 through 52 illustrate an alternative variation or configuration of the means and assembly for connecting a stabilizing element, such as stabilizing element  400 , to a connecting member such as connecting member  418  and, more particularly to the tabs  420  and  422 . Thus, referring to FIG. 50, the stabilizing element  400  is attached to or co-acts with the connecting element  418  and more particularly the tabs  420  and  422  by means of a U-shaped fastener or clip  480  which is also made of a metal material. For example, the clip  480  may be a steel, U-shaped or horseshoe-shaped member as depicted in FIG.  51 . The clip  480  thus includes generally parallel, spaced legs  482  and  484  connected by an arcuate or curved crown  486 . 
     The clip or fastener or connector  480  fits through the openings or passageways  424  and  426  in the projecting tabs  420  and  422  as well as through the looped ends  410  and  412  as depicted in FIG.  50 . The preferred final orientation of the fastener  480  is depicted in FIG.  50 . FIG. 52 is a top-plan view depicting the manner by which the stabilizing element  400  may be positioned in cooperation with the projecting tabs  420  and  422  so as to align passage  414  with passageways  424  and  426 . FIG. 53 depicts the first step when connecting the element  400  to the member  418  by means of the fastener or connector  480 . Thus a leg  482  of the connector  480  may be initially inserted through the associated passage  414  and passageways  424 ,  426 . The connector  480  may then be left in the position depicted in FIG. 53 or alternatively further manipulated so as to assume the configuration of FIG.  50 . The configuration of the connector  480  may also be altered to facilitate assembly. For example, it may be more U-shaped than depicted in the FIG.  53 . Also, the crown  486  may be flatter or more arcuate. Many variants of the shape of the clip  480  may be provided. 
     FIG. 54 discloses yet another variant of a stabilizing element. Stabilizing element  490  is comprised, as depicted in FIGS. 54 and 55, of generally parallel horizontal and longitudinally extending reinforcing members, bars or rods  492  and  494 . The members or rods  492  and  494  are spaced from one another and connected by cross members or cross bars  496  in the manner previously described. The rods or longitudinal members  492  and  494  are spaced typically about two inches (2″) apart. 
     In the embodiment shown, the rods  492  and  494  are welded to a planer plate  497 . The planer plate  497  is generally rectangular in configuration and the rods  492  and  494  are welded to the lateral parallel spaced edges of the plate  497 . The plate  497  includes a passage or opening  498  through one end. The plate  497  may thus be attached by means of a bolt  499  through parallel spaced projecting tabs  500  and  501  of a cast-in-place retaining element  502 . The retaining element  502  is cast in place in a pre-existing pre-cast concrete facing panel  503 . The bolt  499  is then retained in position by means of a nut  504 . 
     Again, the configuration of the stabilizing element  490  depicted in FIGS. 54 and 55 may be utilized in combination with an attachment element such as the element  266  in FIG.  37 . The element  266  may co-act with a block  40  of the type previously described. The plate  497  may also be connected to a block  40  in the manner depicted in FIG. 39 wherein plate  497  passes through a slot  290  and is held by a pin  294 . The stabilizing element  490  may also be utilized in combination with numerous types of facing elements including panels such as panel  503 , blocks such as blocks  40 , and wire facing panels. 
     FIGS. 56 and 57 illustrate an alternative construction for a stabilizing element which is a variation of the type shown in FIGS. 54 and 55. The variation of FIGS. 56 and 57 includes parallel, horizontal bars or rods  510  and  512  which are spaced one from the other by means of cross bars such as cross bar  514 . A plate  516  is a generally planer plate and includes upwardly projecting, spaced, parallel ribs  518  and  520 . The ribs  518  and  520  typically are cross ribs which connect between the opposite sides  522  and  524  of the plate  516 . In this manner, the parallel longitudinal rods  510  and  512  may be welded to the ribs  518  and  520  as depicted in FIG.  57 . The plate  516  also includes a through passage  526 . The passage  526  enables the stabilizing element, depicted in FIGS. 56 and 57, to be attached to wall panels, blocks, wire facing elements and other elements in a manner such as depicted in FIGS. 54,  55 ,  37  or  39  for example. 
     FIG. 58 depicts a wall panel  530  which is a precast wall panel having a tab or attachment plate construction  532  cast in place therein. As depicted in FIG. 59, the plate  532  includes a flat tab section  534  and wing sections  536  and  538  which are cast in the panel  530 . A through passage  540  in the plate  534  permits receipt of a fastener bolt  542  for attachment of the looped ends  410  and  412  of stabilizing element  400  previously described. A nut  544  is threaded on the bolt  542  and washers  546  and  548  assist in retention of the stabilizing element  400  on the connector  532 . 
     FIG. 60 illustrates an alternative construction for a precast facing panel which is useful for connection to stabilizing elements  400 . Thus, a cast in place panel  550  includes a metal strip  552  having opposite ends  554  and  556  projecting from the cast in place panel  550 . The ends  554  and  556  each include a through passage adapted for receipt of a bolt  542  which retains the stabilizing elements  400  attached to the wall panel  550  in the same manner as described with respect to FIG.  58 . 
     FIG.  61  and FIG. 62 together illustrate another alternative construction for a stabilizing element as well as a connection construction for attachment of the stabilizing element to a precast wall panel, for example. Referring to those figures, therefore, the stabilizing element includes first and second parallel spaced rods or reinforcing bars  560  and  562  which are designed to extend longitudinally and generally horizontally into an earthen work bulk form. The bars  560  and  562  are connected by cross members or cross bars or cross rods  564 , for example. At each end of each of the separate horizontal bars  560  and  562 , include a vertical loop. Thus, bar  562  includes a vertical loop  566 . The vertical loop is thus formed by bending the ends of the rod  562  and forming a closed loop. The closed loop may be welded at the juncture crossover point  568  of the end of the rod  562 . 
     Each end of the rod  562  and each end of the rod  564  is formed in the manner described. Further, the precast wall panel  570  includes rods  572  and  574  cast in place therein. The rods  572  and  574  also project from the panel  570  and are formed in a closed loop  576 . Again where the closed loop folds over itself or has a crossover point  578 , the rod may be welded to insure a good secure connection. The loops  566  and  576  may then be aligned with one another and a tie bar or cross member  580  is inserted through the aligned loops. The cross member  580  may thus connect the stabilizing element  560  to the connecting members  572  and  574 . Additionally, the stabilizing elements  560  may be connected to one another in the same manner utilizing a cross bar  580 . The cross bar  580  in the embodiment shown is a straight cross bar member. However, various combinations of such a connector may be utilized. For example, the cross bar  580  may constitute a bar having legs and a crown. The cross bar may have legs which are folded over on one another after being inserted through the loops  566  and/or  576 . As depicted, a number of stabilizing elements  560  may be attached on to the other. The stabilizing elements  560  may also be connected to various other types of facing elements including blocks and wire facing elements. 
     Other variants of the stabilizing element construction, as well as variant of the connectors of the stabilizing elements to certain wall elements such as precast panels, blocks, wire mesh facing elements and the like are possible. Thus the invention is to be limited only by the following claims and their equivalents.