Abstract:
The present invention relates generally to precast cantilevered retaining walls and methods of using and forming precast cantilevered retaining walls. More specifically, the present invention relates to a cantilevered concrete retaining wall having a base shear key and blockouts for receiving a material that substantially impedes the wing wall from sliding or other inadvertent movement, to a method of retaining a soil embankment with a cantilevered concrete retaining wall, and to a method of manufacturing a precast concrete cantilevered retaining wall.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This Application is a continuation of U.S. patent application Ser. No. 14/064,836, filed Oct. 28, 2013, entitled “Cantilevered Wing Wall,” which is incorporated herein in its entirety by reference. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates generally to precast cantilevered retaining walls. More specifically, the present invention relates to a cantilevered concrete retaining wall having a base shear key and blockouts for receiving a material that substantially impedes the wing wall from sliding or other inadvertent movement. 
     BACKGROUND 
     Retaining walls are subject to various forces that may cause them to fail. Pressure at the toe of the footing is generally larger than pressure at the heel of the footing so retaining walls have an inherent tendency to tilt forward away from an embankment. Occasionally, the base soil is of a poor quality and when sufficient backfill is placed between the backface of the retaining wall and an embankment, for example, the approach fill at a bridge abutment, the backfill pressure produces a settlement with lateral effect into the zone beneath the heel so that the retaining wall may tilt back into the backfill and the embankment. Lateral forces generated by earth and water pressure may cause the base of the retaining wall to slide outward and fail. Retaining walls are generally designed to resist these lateral forces by creating friction between the bottom surface of the footing and the soil. Some soil types are more prone to shifting or erosion and may decrease the friction between the footing and soil. Different soil types exert different amounts of pressure on the retaining wall. Local soil conditions may require an increase in the width of the footing to achieve the required friction between the bottom surface of the retaining wall and the soil to counteract the lateral forces on the retaining wall. However, making the footing wider increases the amount of materials used, increases transportation costs, and requires increased excavation of soil to form a wider subgrade which increases cost and time required for site preparation and installation. In some cases, it may not be possible to increase the footing width based on site requirements. The depth of the footing cover can also be increased in some situations to provide additional resistance to lateral forces; however, this also increases the cost of site preparation because excavation must be deeper, and additional concrete is required which increases costs as well. 
     Concrete retaining walls that are cast-in-place at the job site are known to have a higher coefficient of friction between the footing and the soil compared to precast concrete retaining walls that are manufactured at a precast plant, transported to the job site, and placed on the soil. However, there are several shortcomings in the use of cast-in-place retaining walls compared to the use of precast concrete retaining walls. Creating forms for a retaining wall at a job site is time consuming and may require the presence of many employees at a remote location. The job site may not be as safe for employees as a precast plant due to open excavations, the presence of heavy equipment, and the natural environment. The forms may have to be custom made, increasing labor and material costs and making re-use of the forms unlikely. Placing and aligning reinforcing steel precisely at a job site may be more difficult than at a precast plant, potentially weakening the retaining wall. The concrete for the retaining walls may have to be transported long distances to the job site in individual truckloads increasing transportation and labor costs. Finally, the concrete is exposed to the environment while it is curing which can increase the curing time or adversely affect the strength characteristics of the retaining wall. Construction of the project may be delayed while waiting for the concrete to cure. 
     Due to the numerous limitations associated with cast-in-place retaining walls, there is an unmet need for a precast concrete retaining wall which has a coefficient of friction equivalent to a cast-in-place retaining wall of similar size. 
     SUMMARY OF THE INVENTION 
     In view of the limitations in prior art retaining walls and methods of using them, the present disclosure provides a new and useful precast cantilevered wing wall and a method of use thereof which is cost effective to fabricate, more versatile in use than known prior art retaining walls, and less susceptible to failure. 
     One aspect of the present disclosure is to provide a new precast cantilevered wing wall and method of use thereof that prevents the cantilevered wing wall from sliding or other inadvertent movement. Another aspect of the present disclosure is to provide a new precast cantilevered wing wall that has many novel features not offered by the prior art. One such feature is a base shear key or stem wall adapted to fit into a trench formed in the subgrade beneath the footing of the cantilevered wing wall. Another novel feature includes one or more blockouts formed through the footing. The precast cantilevered wing wall and base shear key are placed on the prepared subgrade and the base shear key is placed in the trench. A material that replicates the strength of compacted soil is poured or deposited through the blockouts to fill voids between the soil of the subgrade and the shear key to lock the cantilevered wing wall in place. The material may be any material that fills the voids and replicates the strength of compacted soil such as grout, cement, concrete, mortar, controlled density fill, adhesives, hydro compacted sand, or any combination thereof. 
     In one embodiment, the cantilevered wing wall may be assembled from individual precast concrete sections. In another embodiment, the cantilevered wing wall may be precast monolithically as one integral piece without any individual components, joints, or necessity to interconnect any components. 
     In one embodiment, a method of retaining an embankment with a precast cantilevered wing wall is disclosed, the method generally comprising (1) providing a precast cantilevered wing wall having a stem of a predetermined height, length, and thickness, a footing interconnected to the stem, the footing extending laterally from a front face of the stem to form a toe and the footing extending laterally from a back face of the stem to form a heel, the footing having a predetermined thickness, a base shear key extending downwardly a predetermined depth from a substantially horizontal plane defined by the footing, and a plurality of blockouts formed through the footing between the stem and the base shear key, wherein each of the plurality of blockouts have a sufficient dimension to receive a grout material; (2) excavating soil to form a subgrade of a determined width, length, and depth; (3) excavating soil to form a trench of a second determined width, length, and depth in the subgrade; (4) placing the cantilevered wing wall on the subgrade, wherein the base shear key of the cantilevered wing wall extends at least partially into the trench; and (5) filling the trench and at least one of the plurality of said blockouts at least partially with the grout material that fills the void between footing and the subgrade, wherein the grout material replicates the strength of compacted soil, wherein said grout material comprises at least one of a grout, a cement, a concrete material, a mortar, a controlled density fill, an adhesive, a hydro compacted sand, a controlled density fill, and an aggregate, or any combination thereof. 
     In one embodiment, the subgrade soil may optionally be compacted to a determined density. In another embodiment, at least one blockout may be formed through the footing between the stem and the toe. In yet another embodiment, the footing may be formed without the base shear key. In another embodiment, drain holes may be formed through the stem. In yet another embodiment, a drainage system may optionally be installed between the back face of the stem and the embankment. In still another aspect for further stabilization, one or more soil nails may optionally be installed through at least one of the plurality of said blockouts. In another embodiment, anchors may be embedded within the precast cantilevered wing wall so that the cantilevered wing wall can be lifted, transported, and placed in a position of use. The method may further optionally comprise placing infill material between the wall and the embankment to a determined height, placing second infill material in front of the stem above the footing to a final grade line, and compacting the infill material and the second infill material to a second determined density. 
     In another embodiment, a precast cantilevered wing wall is disclosed, the cantilevered wing wall comprising: a stem of a predetermined height, length, and thickness; a footing connected to the stem, the footing extending laterally from a front face of the stem to form a toe and the footing extending laterally from a back face of the stem to form a heel; and a plurality of blockouts formed through the footing, wherein each of the plurality of blockouts have a sufficient size to receive at least one of a grout material and a reinforcing bar. In an embodiment, the plurality of blockouts may optionally be comprised of two or more rows of blockouts. In another embodiment, at least one blockout is formed between stem and the toe. In yet another embodiment, the plurality of blockouts may optionally be formed through the footing to have an irregular spacing. In still another optional embodiment, the blockouts may have a shape resembling at least one of a parallelogram, a square, a rectangle, a circle, a triangle or any combination thereof. In one embodiment, a base shear key extends down a predetermined depth from a substantially horizontal plane defined by the footing. In another embodiment, the stem has a first predetermined height on a right side of the cantilevered wing wall and a second predetermined height on a left side of the cantilevered wing wall and the first predetermined height is optionally greater than the second predetermined height. In still another embodiment, the first predetermined height is optionally less than the second predetermined height. In yet another embodiment, the plurality of blockouts have an irregular spacing. In still another embodiment, the plurality of blockouts are formed through the footing between the stem and a rear portion of the heel. In another embodiment, at least one of the plurality of blockouts is formed between the stem and a forward-most portion of the toe. In yet another embodiment, the cantilevered wing wall further comprises anchors, the anchors having a first end at least partially embedded in the concrete and a second end adapted to be manipulated by lifting equipment to lift, transport, and/or place the cantilevered wing wall in a position of use. 
     In yet another embodiment, a method of manufacturing a monolithic precast concrete cantilevered retaining wall is disclosed and which generally comprises (1) creating a form which defines the geometry of the retaining wall wherein the form comprises a stem of a predetermined height, length, and thickness, a footing connected to the stem, the footing having a predetermined thickness and extending laterally a width from a front face of the stem to form a toe and extending laterally a width from a back face of the stem to form a heel, optionally a shear key extending down a predetermined depth from a substantially horizontal plane defined by the footing, and a plurality of blockouts through the footing; (2) placing reinforcing steel in the form; (3) pouring a predetermined volume of concrete into the form; and (4) removing the form after the concrete has cured, wherein the precast concrete cantilevered retaining wall can be lifted, transported, and place in a position of use. In one embodiment, the plurality of blockouts are formed between the stem and the heel to create a void adapted to receive reinforcing materials such as metal rebar and/or steel. In one optional embodiment, at least one blockout is formed between the stem and the toe. In still another embodiment, the plurality of blockouts may have an irregular size. In yet another embodiment, a shape of at least one of the plurality of blockouts differs from a second shape of a second of the plurality of blockouts. In yet another embodiment, anchors may be embedded within the precast cantilevered wing wall, the anchors having a first end at least partially embedded within the cantilevered wing wall and a second end adapted to be engaged by lifting hardware to lift, transport, and place the cantilevered wing wall in a position of use. 
     Additional features and advantages of embodiments of the present disclosure will become more readily apparent from the following discussion, particularly when taken together with the accompanying drawings. 
     References made herein to a “cantilevered wing wall” or aspects thereof should not necessarily be construed as limiting the present invention to a particular type of retaining structure. It will be recognized by one skilled in the art that the present invention may be used with other types of structures such as gravity walls, semi-gravity wall, conventional walls, non-gravity cantilevered wall, anchored walls, abutments, culverts, retaining walls, wing walls, and the like to retain an embankment. Accordingly, the term “cantilevered wing wall” is intended to cover all types of structures designed to retain an embankment of any type. 
     The terms “grout material” or “grout” as used herein refer to any material that replicates the strength of compacted soil. Such materials includes, but are not limited to, grout, cement, concrete, mortar, putty, plastic, polymer concrete, aggregate, controlled density fill, adhesives, hydro compacted sand, or any combination thereof, or similar binding materials that may be represented in a variety of types and composition mixes having various combinations of ingredients as will be recognized by one of skill in the art. 
     The phrase “material that replicates the strength of compacted soil” as used herein refers to any material such as grout, cement, concrete, mortar, controlled density fill, adhesives, concrete, hydro compacted sand, or any combination thereof used to fill voids and/or trenches beneath a footing of a cantilevered wing wall. 
     Although generally referred to herein a “precast” cantilevered wing wall, aspects of the present invention may be used with cast-in-place cantilevered wing walls as will be recognized by one of skill in the art. 
     The phrases “at least one,” “one or more,” and “and/or,” as used herein, are open-ended expressions that are both conjunctive and disjunctive in operation. For example, each of the expressions “at least one of A, B and C,” “at least one of A, B, or C,” “one or more of A, B, and C,” “one or more of A, B, or C” and “A, B, and/or C” means A alone, B alone, C alone, A and B together, A and C together, B and C together, or A, B and C together. 
     Unless otherwise indicated, all numbers expressing quantities, dimensions, conditions, and so forth used in the specification and claims are to be understood as being modified in all instances by the term “about.” 
     The term “a” or “an” entity, as used herein, refers to one or more of that entity. As such, the terms “a” (or “an”), “one or more” and “at least one” can be used interchangeably herein. 
     The use of “including,” “comprising,” or “having” and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. Accordingly, the terms “including,” “comprising,” or “having” and variations thereof can be used interchangeably herein. 
     It shall be understood that the term “means” as used herein shall be given its broadest possible interpretation in accordance with 35 U.S.C., Section 112(f). Accordingly, a claim incorporating the term “means” shall cover all structures, materials, or acts set forth herein, and all of the equivalents thereof. Further, the structures, materials, or acts and the equivalents thereof shall include all those described in the summary of the invention, brief description of the drawings, detailed description, abstract, and claims themselves. 
     The Summary of the Invention is neither intended nor should it be construed as being representative of the full extent and scope of the present invention. Moreover, references made herein to “the present invention” or aspects thereof should be understood to mean certain embodiments of the present invention and should not necessarily be construed as limiting all embodiments to a particular description. The present invention is set forth in various levels of detail in the Summary of the Invention as well as in the attached drawings and the Detailed Description and no limitation as to the scope of the present invention is intended by either the inclusion or non-inclusion of elements or components. Additional aspects of the present invention will become more readily apparent from the Detailed Description, particularly when taken together with the drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings, which are incorporated herein and constitute a part of the specification, illustrate embodiments of the invention and together with the summary of the invention given above and the detailed description of the drawings given below serve to explain the principles of these embodiments. In certain instances, details that are not necessary for an understanding of the disclosure or that render other details difficult to perceive may have been omitted. It should be understood, of course, that the invention is not necessarily limited to the particular embodiments illustrated herein. Additionally, it should be understood that the drawings are not necessarily to scale. 
         FIG. 1  is an isometric view of a cantilevered wing wall according to one embodiment; 
         FIG. 2  is a side view of a cantilevered wing wall according to an embodiment; 
         FIG. 3  is fragmentary side view of a cantilevered wing wall according to an embodiment; 
         FIG. 4  is a front view of multiple cantilevered wing walls positioned adjacent one another in series according to one embodiment of the present invention; 
         FIG. 5  is a top view of a cantilevered wing wall according to an alternate embodiment of the present invention; 
         FIG. 6  is a top view of a cantilevered wing wall according to yet another embodiment of the present invention; 
         FIG. 7A  is a top plan view of multiple cantilevered wing walls positioned adjacent one another in a structure according to an embodiment; 
         FIG. 7B  is a plan view of  FIG. 7A  on the line  7 B; and 
         FIG. 7C  is a plan view of  FIG. 7A  on the line  7 C. 
     
    
    
     A component list of the various components shown in drawings is provided herein: 
     
       
         
               
               
             
           
               
                   
               
               
                 Number 
                 Component 
               
               
                   
               
             
             
               
                 10 
                 cantilevered wing wall 
               
               
                 14 
                 stem 
               
               
                 18 
                 stem height 
               
               
                 19 
                 stem length 
               
               
                 20 
                 stem thickness 
               
               
                 22 
                 footing 
               
               
                 23 
                 footing thickness 
               
               
                 24 
                 toe width 
               
               
                 25 
                 heel width 
               
               
                 26 
                 back face 
               
               
                 30 
                 front face 
               
               
                 34 
                 toe 
               
               
                 38 
                 heel 
               
               
                 40 
                 anchor 
               
               
                 42 
                 base shear key 
               
               
                 43 
                 depth 
               
               
                 44 
                 width 
               
               
                 46 
                 blockouts 
               
               
                      46A 
                 circular blockout 
               
               
                 47 
                 distance from heel 
               
               
                 48 
                 distance from edge 
               
               
                 49 
                 blockout width 
               
               
                 50 
                 blockout length 
               
               
                 51 
                 distance of separation 
               
               
                 52 
                 joint 
               
               
                 54 
                 embankment 
               
               
                 58 
                 subgrade 
               
               
                 62 
                 subgrade depth 
               
               
                 66 
                 footing cover 
               
               
                 70 
                 final grade 
               
               
                 74 
                 trench 
               
               
                 78 
                 grout 
               
               
                 82 
                 backfill 
               
               
                 86 
                 footing key 
               
               
                 90 
                 buttress 
               
               
                 94 
                 counterfort 
               
               
                 98 
                 vertical seam 
               
               
                 102  
                 right end 
               
               
                 106  
                 left end 
               
               
                   
               
             
          
         
       
     
     DETAILED DESCRIPTION 
     Various embodiments of the present invention are described herein and as depicted in the drawings. The present disclosure has significant benefits across a broad spectrum of endeavors. It is the applicant&#39;s intent that this specification and the claims appended hereto be accorded a breadth in keeping with the scope and spirit of the invention being disclosed despite what might appear to be limiting language imposed by the requirements of referring to the specific examples disclosed. It is expressly understood that although  FIGS. 1-6  depict embodiments of precast cantilevered wing walls, the present invention is not limited to these embodiments and may be used in any form of application related to retaining walls or systems and methods to prevent the inadvertent movement of soil. 
     Referring now to  FIG. 1 , an embodiment of a precast cantilevered wing wall  10  of the present invention is shown. In the example of  FIG. 1 , the cantilevered wing wall  10  includes a stem  14  having a predetermined height  18 , length  19 , and thickness  20 . The stem  14  is connected to a footing  22  with a predetermined thickness  23 . The stem has a back face  26  and a front face  30 . The footing  22  may project laterally a predetermined width  24  from the front face  30  to form a toe  34  and/or from the back face  26  a predetermined width  25  to form a heel  38 . In one embodiment, the cantilevered wing wall further comprises anchors  40 . The anchors  40  generally have a first portion at least partially embedded in the concrete and a second portion adapted to be engaged by lifting equipment to lift, transport, and/or install the cantilevered wing wall. The anchors  40  may be embedded within at least one of the stem  14  and the footing  22 . Optionally, a base shear key  42  extends down a predetermined depth  43  from the heel  38  of the footing  22 . The base shear key has a predetermined width  44  extending from the heel  38  in the direction of the toe  34  under the footing  22 . The stem height  18 , length  19 , and thickness  20 , footing thickness  23 , toe width  24 , heel width  25 , shear key depth  43 , and shear key width  44  may be any dimension required based on the design criteria of the installation. In one embodiment, as shown in  FIG. 1 , it is anticipated that the shear key  42  may have a depth  43  of 12 inches and a width  44  of 12 inches. However, the base shear key  42  may have any depth  43  or width  44  required by the design criteria of the installation. For example, the base shear key could have a depth  43  of 24 inches and a width  44  of 12 inches. The base shear key  42  can be of any shape such as a tapered shape as illustrated in  FIG. 2 . 
     Blockouts  46  are formed through the footing  22  between the stem wall  14  and the base shear key  42 . Although the blockouts  46  are shown as generally square shaped, it should be understood that they may be of any shape, including a circle, triangle, rectangle, or parallelogram, or one or more combinations thereof. Additionally, blockouts  46  of different shapes and sizes may be formed through the footing  22 . The blockouts  46  may be formed a distance  47  from the heel  38  and a distance  48  from the left and right edges of the footing  22 . The blockouts  46  may have a width  49  and a length  50 . Any number of blockouts  46  may be formed through the footing  22 . A distance  51  may separate each blockout  46  from an adjacent blockout  46 . Optionally, the distance  51  may be unequal wherein the blockouts  46  may be spaced irregularly through the footing  22 . In one embodiment, illustrated in  FIG. 6 , the blockouts may be arranged in more than one row from the right end  102  to the left end  106  of the footing  22 . In one embodiment, as shown in  FIG. 1 , the blockouts may be formed a distance  47  of 12 inches from the heel, may be equally spaced a distance  48  of 4 inches from the left and right edges of the footing  22 , may have a width  49  of 12 inches and a length  50  of 12 inches, and each blockout may be equally separated from an adjacent blockout by a distance  51  of 4 inches. As will be appreciated by one skilled in the art, the actual length  50  and width  49  of the blockouts and the distances  47 ,  48 , and  51  may vary as required by design criteria for each particular installation. Various dimensions are provided in  FIG. 1  to illustrate one exemplary embodiment and it is expressly contemplated that dimensions of the cantilevered wing wall, the base shear key, and the placement, dimensions, and spacing of the blockouts may be varied and still comport with the scope and spirit of the present disclosure. Although not shown, the precast cantilevered wing wall  10  may be reinforced with steel rebar or other materials with high rigidity to help impede movement of the wing wall after installation. 
       FIG. 2  illustrates another embodiment of a precast cantilevered wing wall  10  of the present invention. The stem  14  is connected to the footing  22  at a joint  52  using any material or method known in the art. For example, the stem  14  may be joined to the footing  22  using a key interlocking with a groove or depression. In one embodiment, the cantilevered wing wall  10  may be formed in one piece wherein the stem  14  and the footing  22  are formed together at the same time to form a monolithic precast structure. The back face  26  is generally designed to engage an embankment  54  comprised of soil or other material. The footing  22  is placed on a prepared subgrade  58  excavated to a depth  62  determined so that the footing  22  may be covered to a predetermined depth  66  below the final grade  70 . The base shear key  42  fits into a trench  74  dug in the subgrade  58 . In an alternate embodiment, after the retaining wall is placed on the subgrade  58 , a plurality of soil nails (not illustrated) of any type or size known in the art may optionally be emplaced through the blockouts  46  for further stabilization. As illustrated in  FIG. 3 , grout  78  is poured through the blockouts  46  to fill the void between the subgrade and footing and the trench  74 . Pouring grout  78  into the trench  74  through the blockouts  46  increases the coefficient of friction between the footing and the subgrade  58  soil such that the coefficient of friction for the precast cantilevered wing wall is equivalent to the coefficient of friction of a cast-in-place cantilevered wing wall of a similar size. 
     Returning to  FIG. 2 , after the grout material  78  cures, the footing  22  is covered and backfill  82  is placed between the embankment  54  and the back face  26 . Also shown in the embodiment of  FIG. 2 , the footing  22  may optionally include a footing key  86  that extends down from the bottom of the footing  22 . Buttresses  90  may optionally be added to the front face  30  and counterforts  94  may optionally be added to the back face  26  based on design criteria. One or both of the back face  26  and the front face  30  may have a batter such that the stem  14  has a thickness  20 A near the footing  22  greater than a thickness  20 B at the top. 
     Referring to  FIG. 4 , three cantilevered wing walls  10 A,  10 B, and  10 C of another embodiment of the present invention are illustrated. The individual wing walls  10 A-C are positioned adjacent one another or aligned at vertical seams  98 . Each wing wall  10 A-C has a stem  14  with a height  18 A greater on the right end  102  than a height  18 B on the left end  106  so that in this perspective the front face  30  of the stem  14  is higher on right end  102 . In another embodiment, the individual wing walls may be higher on the left end than on the right end providing a negative slope in this perspective. Individual cantilevered wing walls with a positive or negative slope may be positioned adjacent to each other and/or to individual cantilevered wing walls with a constant stem height to produce a profile of a varying height. In one embodiment, individual cantilevered wing walls may be positioned adjacent one another and then joined together using mechanical fasteners, by welding pre-placed joints, with a grout, or one or more other means. 
       FIG. 5  illustrates yet another embodiment of a cantilevered wing wall. The footing  22  extends away from the stem  14  further on the left end  106  than on the right end  102  giving the footing  22  a trapezoidal shape. Said another way, the heel projection  25 A on the left end  106  is larger than the heel projection  25 B on the right end  102 . Of course, as one skilled in the art will recognize, the right end  102  could extend further than the left end  106 . The footing  22  projecting laterally from the front face  30  may also have a trapezoidal or other shape.  FIG. 5  also illustrates a circular blockout  46 A formed in conjunction with rectangular blockouts  46 . 
       FIG. 6  illustrates another embodiment of a cantilevered wing wall. The footing  22  extends away from the stem  14  an equal distance on the left end  106  and on the right end  102 . Two rows of blockouts  46  are formed through the footing  22  between the heel  38  and the stem  14 . The blockouts  46  have an irregular spacing. Optional blockouts  46  have been formed through the footing  22  between the toe  34  and the stem  14 . 
       FIG. 7A  illustrates sections of cantilevered wing walls  10 D- 10 M of the present positioned adjacent one another. The cantilevered wing walls  10 D- 10 M are aligned with other precast concrete elements to form a structure.  FIG. 7B  illustrates a front view of cantilevered wing walls  10 D- 10 H of  FIG. 7A .  FIG. 7C  illustrates a front view of cantilevered wing walls  10 I- 10 M of  FIG. 7A . Various dimensions, angles, and alignments of cantilevered wing walls  10 D- 10 M are provided in  FIGS. 7A-7C  to illustrate exemplary embodiments of sizes, shapes, and alignments of individual cantilevered wing walls. It is expressly contemplated that sizes, shapes, and alignments of the cantilevered wing walls may be varied and still comport with the scope and spirit of the present disclosure. 
     Some embodiments of the present disclosure may be fabricated to optionally include a variety of simulated material patterns on the front face  30 , including but not limited, to simulated block, brick, stone, cut stone, stone block, flagstone, granite, sandstone, as well as other material and patterns known in the art. The invention may also embody a wide variety of different finishes, colors, and textures such as those commonly utilized in the architectural and stone industries to provide a high quality appearance compatible with any surrounding development. 
     In one embodiment, the cantilevered wing wall may be formed and cast on site, for example, using poured concrete. In some embodiments, other materials may be used including, but not limited to, plastic, polymer concrete, or similar materials that may be represented in a variety of types and composition mixes having various combinations of ingredients such as those found in the manufacture of concrete, plastics, polymers, cement, water, cementitious materials, and chemical and or mineral admixtures, coloring agents which, when combined, will create a concrete material. In one embodiment, blockouts may optionally be formed through the footing between the toe and the stem. In some embodiments, the cantilevered wing wall may optionally be formed without a base shear key or a footing key. 
     The present invention has many benefits compared to prior art cantilevered wing walls. Because the precast cantilevered wing wall of the present invention is more resistant to lateral forces than prior art precast retaining walls, the width of the footing and height of the stem can be reduced, decreasing the amount of material that must be excavated and reducing the amount of material used in the cantilevered wing wall. In addition, installation time may be reduced because if additional stability is required, soil nails may be installed through the blockouts without drilling through the footing. The precast cantilevered wing wall of the present invention is less expensive to manufacture and has a coefficient of friction equivalent to a cast-in-place retaining wall of similar size. The precast cantilevered wing wall of the present invention may also be manufactured in controlled conditions and under close observation resulting in a stronger, more reliable structure. 
     The description of the present invention has been presented for purposes of illustration and description, but is not intended to be exhaustive or limiting of the invention to the form disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art. The embodiments described and shown in the figures were chosen and described in order to best explain the principles of the invention, the practical application, and to enable those of ordinary skill in the art to understand the invention. 
     While various embodiments of the present invention have been described in detail, it is apparent that modifications and alterations of those embodiments will occur to those skilled in the art. Moreover, references made herein to “the present invention” or aspects thereof should be understood to mean certain embodiments of the present invention and should not necessarily be construed as limiting all embodiments to a particular description. It is to be expressly understood that such modifications and alterations are within the scope and spirit of the present invention, as set forth in the following claims.