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 fig1 - 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 fig1 , an embodiment of a precast cantilevered wing wall 10 of the present invention is shown . in the example of fig1 , 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 fig1 , 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 fig2 . 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 fig6 , 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 fig1 , 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 fig1 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 . fig2 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 fig3 , 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 fig2 , 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 fig2 , 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 fig4 , 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 . fig5 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 . fig5 also illustrates a circular blockout 46 a formed in conjunction with rectangular blockouts 46 . fig6 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 . fig7 a 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 . fig7 b illustrates a front view of cantilevered wing walls 10 d - 10 h of fig7 a . fig7 c illustrates a front view of cantilevered wing walls 10 i - 10 m of fig7 a . various dimensions , angles , and alignments of cantilevered wing walls 10 d - 10 m are provided in fig7 a - 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 .