Abstract:
A retaining wall and face for an earthen formation is provided by embedding generally horizontally disposed welded wire soil reinforcing mats within the formation at vertically spaced intervals and securing face members between successive soil reinforcing mats at the face of the formation. The soil-reinforcing mats comprise spaced longitudinal elements extending into the formation and spaced transverse elements welded to and extending across the longitudinal elements in a disposition wherein an outer of the transverse elements extends across the face of the formation and an inner of the elements is spaced inwardly of the face. Each face member is secured between successive upper and lower soil-reinforcing mats by extending an upper portion of the face member behind the outer transverse element of the upper soil reinforcing mat and securing an inwardly extending portion of the face member to connection with an inner transverse element of the lower soil reinforcing mat. Wire baskets are disposed to the interior of the face members to contain a layer of rocks at the face of the formation.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     The present invention relates to the retention of earthen formations with a retaining and reinforcing mechanism made up of vertically spaced welded wire soil-reinforcing mats embedded within a formation, and face members secured to the mats to secure the formation against sloughing. In its more specific aspects, the invention is directed to an improved method and apparatus which accommodates settling of the earthen formation, without bulging of the face members. It is also concerned with an arrangement wherein the face members comprise welded wire gridworks, and a column of rock is contained in baskets to the interior of these gridworks.  
         [0002]     The prior art relating to the present invention is exemplified by U.S. Pat. No. 6,357,970 to Harold K. Hilfiker, one of the co-inventors herein, and William B. Hilfiker. That patent discloses a retaining wall comprised of L-shaped welded wire gridworks having floor sections which are embedded at vertically spaced intervals in the formation being retained and upright face sections which provide a face for the formation. In the structure of the patent, each successive soil-reinforcing mat is supported on a backing mat carried by the face section of the mat therebelow, and the backing mats are movable relative to the face sections to accommodate settlement of the retained formation, without bulging of its face. Other patents of interest to various techniques which have been provided for securing the face sections of compressible welded wire retaining walls together are William K. Hilfiker U.S. Pat. Nos. 4,505,621, 4,856,939, 5,722,799 and 5,733,072.  
       SUMMARY OF THE INVENTION  
       [0003]     The present invention provides a reinforced soil retaining wall for an earthen formation wherein welded wire soil-reinforcing mats are embedded within the formation at vertically spaced intervals and welded wire face members are secured between the mats at the face of the formation. The face members are separate from the mats and so secured thereto as to accommodate settlement of the formation, without bulging. In a preferred embodiment, baskets are provided to the interior of the face members to contain rock at the face of the formation.  
         [0004]     The invention also provides an improved face member for securement between successive soil-reinforcing mats. The member comprises an L-shaped body formed with a vertically extending face section and a horizontally extending foot section, which body has prongs extending upwardly from the face section for engagement with a mat disposed thereabove, and hooks extending from the foot section for engagement with a mat disposed therebelow, interiorally of the face of the formation.  
         [0005]     A principal object of the present invention is to provide a soil-reinforced retaining wall for an earthen formation, wherein the face members of the wall are separate from the soil-reinforcing elements and so secured thereto that settling of the formation does not result in bulging of the face members.  
         [0006]     Another object of the invention is to provide a wire faced retaining wall for a soil-reinforced earthen formation, wherein rock baskets are provided to the interior of the face to contain rock within a relatively narrow vertical column.  
         [0007]     Still another object related to the later object is to provide such a wall wherein the face has layered sections and a basket is provided to the interior of each section, with successive baskets being in open communication to provide a continuous rock column over the height of the formation.  
         [0008]     Another object of the invention is to provide such a layered wall wherein the uppermost layer of the wall is provided by a wire basket of greater breath than the baskets therebelow, to provide a buttress for the top of the formation.  
         [0009]     Still another object of the invention is to provide such a wall wherein the buttress forming basket at the top of the formation is in open communication with the basket therebelow, so that the rock within the buttress forming basket forms part of the column of rock at the face of the formation.  
         [0010]     Yet another and more specific object of the invention is to provide a soil-reinforced retaining wall for an earthen formation wherein the soil-reinforcing elements comprise welded wire gridworks and the face members of the wall are separate from the gridworks and connected thereto so as to be compressible, without bulging, and to be secured against outward movement by two transverse wires of each gridwork.  
         [0011]     Another and more general object of the invention is to provide a method of forming a soil-reinforced wall for an earthen formation wherein the soil-reinforcing elements comprise welded wire mats and the face of the wall is comprised of welded wire members separate from the mats, with basket structures to the interior thereof containing a column of rocks extending over the height of the wall.  
         [0012]     These and other objects will become more apparent from the following detailed description and accompanying drawings. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0013]      FIG. 1  is a cross-sectional elevational view of a soil-reinforced wall constructed according to the present invention;  
         [0014]      FIG. 2  is a perspective view of the wall shown in  FIG. 1 , with parts thereof broken away;  
         [0015]      FIG. 2A  is a sectional view taken within the boundary designated by line  2 A of  FIG. 2 ;  
         [0016]      FIGS. 3A, 3B ,  3 C,  3 D,  3 E,  3 F,  3 G and  3 H are diagrammatic views, in elevational cross-section, schematically illustrating the successive steps for constructing a soil-reinforced retaining wall according to the present invention;  
         [0017]      FIG. 4  is a cross-sectional elevational view, with parts thereof broken away, illustrating the inventive connection between the face member foot section and the soil-reinforcing mat, as the connection appears before compression of the face member;  
         [0018]      FIG. 5  is a cross-sectional elevational view, similar to  FIG. 4 , illustrating the inventive connection between the face member foot section and the soil-reinforcing mat, as the connection appears after compression of the face member;  
         [0019]      FIG. 6  is a perspective view, illustrating a face member according to the present invention, in the process of being connected to the soil-reinforcing mat disposed therebelow;  
         [0020]      FIG. 7  is an exploded perspective view, illustrating a basket and filter fabric layer being assembled into place behind the face member of the invention;  
         [0021]      FIGS. 7A and 7B  are sectional views taken within the boundaries designated by lines  7 A and  7 B of  FIG. 7 ;  
         [0022]      FIG. 8  is a perspective view, with parts thereof broken away, illustrating the face member and basket of the invention engaged with a soil-reinforcing mat therebelow, with a partial layer of rock and backfill in place;  
         [0023]      FIG. 9  is a perspective view, with parts thereof broken away, illustrating the face member and basket of the invention engaged with a soil-reinforcing mat therebelow, with a full layer of rock and backfill in place; and,  
         [0024]      FIG. 10  is a diagrammatic perspective view, illustrating the spanning relationship of the rock baskets relative to the face members. 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT  
     Structure  
       [0025]     Referring now to  FIG. 1 , the basic elements are soil-reinforcing mats SM, face members FM, narrow rock baskets NRB, top basket TRB, and filter fabric layers FL. Preferably, the mats and face members, as well as all other metallic components are fabricated of steel and coated with a suitable anticorrosive coating, such as zinc.  
         [0026]     The soil-reinforcing mats SM and face members FM are of a welded wire construction and typically constructed of W3.5 to W12 wire. The length of the mats SM is determined by the depth of the formation being reinforced. A typical width for the soil-reinforcing mats SM and the face member FM is 8 feet.  
         [0027]     A typical height for the face members, as measured between the uppermost and lowermost transverse wires thereof, is 36 inches. Typical dimensions for the narrow rock baskets NRB are 8 feet long by 3 feet high by 1 foot deep. Typical dimensions for the top basket TRB are 8 feet long by 3 feet deep by 3 feet high.  
         [0028]     The soil-reinforcing mats SM have longitudinally extending wires  10  with transverse wires  12  extending thereacross, which longitudinal and transverse wires are welded together at their intersections. The face members FM have longitudinal wires  14 , with transverse wires  16  extending thereacross at spaced intervals. The longitudinal wires  14  and transverse wires  16  are also welded together at their intersections. Typical spacing for the wires in both the mats SM and the members FM is 8 inches for the longitudinal wires and 21 inches for the transverse wires.  
         [0029]     The face members FM are all of the same construction and each comprise a vertically extending face section  18  and a horizontally extending foot section  20 . Prongs  22  extend upwardly from the face sections, which prongs are formed by distally extending ends of the longitudinal wires  14 . Hooks  24  extend upwardly from the foot sections, which hooks are also formed by distal extensions of the longitudinal wires  14 .  
         [0030]     The baskets NRB comprise welded wire front and rear panels  26  and  28 , respectively, secured together in spaced relationship by welded wire diaphragms  30 . The diaphragms  30  are a frame like construction; comprising horizontal elements  32  welded to vertical elements  34 . Spiral connectors  35 ,  37  (see  FIGS. 7A and 7B ) hingedly secure the diaphragms to the front and rear panels. The mesh of the front and rear panels is sufficiently small to prevent fill rock from passing therethrough. The horizontal elements  32  are sufficiently spaced so as to not impede the passage of rock therethrough. The baskets NRB are open at the top and bottom so that rock may pass therethrough.  
         [0031]     The top basket TRB is of a construction similar to the narrow baskets NRB, except for its depth. It comprises front and rear panels  36  and  38 , respectively, and connecting diaphragms  40 . The diaphragms  40  comprise horizontal elements  42  welded to intersecting vertical elements  44 . The front and rear panels are hingedly secured to the diaphragms by spiral connectors  35 ,  37  corresponding to those used for the baskets NRB. A lid  48  is hingedly secured to the top of the basket TRB by a spiral connector  50  (see  FIG. 2A ). The lid is comprised of intersecting welded wires and, upon filling of the basket TRB with rock, is secured in closed condition by a spiral connector  52  (see  FIG. 2 ).  
       Assembly  
       [0032]     The assembly sequence for constructing a wall according to the present invention is diagrammatically illustrated in  FIGS. 3A through 3H .  
         [0033]      FIG. 3A  shows the first step of the assembly process wherein a foundation F has been formed at the foot of the formation over which the soil-reinforced wall is to be constructed. As there shown, the top of the foundation is generally horizontal and the first soil-reinforcing mat SM is in the process of being placed.  
         [0034]      FIG. 3B  shows step  2  of the assembly process wherein the foot section  20  of the first face member FM is being secured to the lowermost soil-reinforcing mat SM. This step is shown in more detail in  FIGS. 6 and 7 , wherein it will be seen that the hooks  24  are engaged beneath a transverse wire  12 A spaced one inwardly from the outermost transverse wire  12 B, and that the face member is then swung downwardly so that section  18  thereof is in a vertical disposition. In the later condition, the transverse wire  16 A of the foot section  20  rests on the longitudinal wires  10  of the soil-reinforcing mat, and the face section  18  is disposed to the interior of the outermost transverse wire  12 B of the soil-reinforcing mat (see  FIG. 4 ). As a result, the face member is secured against outward displacement by both the wire  12 A and the wire  12 B. This has the advantage that the connection between the soil-reinforcing mat and the face member is not dependent upon the integrity of a single transverse wire of the soil-reinforcing mat. At the same time, however, the face member may slide downwardly relative to the wire  12 B, as shown in  FIG. 5 . The provision of such downward movement permits the face member to compress, as may result from settlement of the earthen formation being retained, without bulging.  
         [0035]      FIG. 3C  shows the third step of the assembly technique wherein baskets NRB are placed to the interior of the first course of face members FM and filter fabric layer FL is disposed over the interior of the baskets. This assembly step may be seen, in more detail, in  FIG. 7 . During the course of the assembly process, hog rings HR are secured between the baskets, face members and filter fabric layers. Such hog rings are shown at the top of  FIG. 3C . While the hog rings provide a relatively secure connection, they may bend and release as the earthen formation settles.  
         [0036]     The step of  FIG. 3C  also includes backfilling and compacting soil to the interior of the basket NRB to a level of approximately 12 inches, and then filling the baskets NRB with rock to level of approximately 18 inches. This process is continued by successively backfilling and compacting additional layers of soil behind the lower most level of baskets NRB, as depicted in  FIGS. 3D and 3E .  
         [0037]     In the step of  FIG. 3D , soil is backfilled and compacted to a level of approximately 24 inches and the basket NRB is filled to its upper level.  FIG. 3E  shows the next step wherein soil is backfilled and compacted to the upper level of the first layer of baskets. This may be seen, in more detail, in  FIG. 9 .  
         [0038]     The step of  FIG. 3E  also includes placing the next lift of soil-reinforcing mats SM over the backfill soil so that the outermost transverse wires  12 B of the mats extend across the face members FM to the exterior of the prongs  22 . Through the later interrelationship, as may be seen from the step of  FIG. 3F , the second lift of soil-reinforcing mats serves to secure the upper ends of the face members therebelow, against outward displacement, while permitting the members to slide downwardly. This interrelationship is shown in larger detail in  FIGS. 4 and 5 . It also may be seen from  FIGS. 1 and 2 .  
         [0039]      FIG. 3F  shows the placement of the next course of face members FM over the soil-reinforcing mats supported on the first level of backfill. This placement corresponds to that described with reference to  FIGS. 3B and 6 . It is completed by swinging the face member so that its face section  18  is near-vertical. Thereafter, the steps depicted in  FIGS. 3C, 3D  and  3 E are repeated until the wall reaches the lower level of the top lift, as seen in  FIG. 3G .  
         [0040]     Upon reaching the later level, the top basket TRB is placed on the top most soil-reinforcing mat SM so that the outside surface of the basket is to the interior of the prongs  22  of the face member immediately therebelow. The lower innermost corner of the basket TRB is preferably spiral connected to the soil-reinforcing mat. Backfill soil is then placed and compacted behind the basket TRB in successive 12 inch lifts as the basket TRB is filled with rock, until the backfill reaches the level of the top of the basket TRB. At this point, the rear top edge of the lid  48  is secured in the closed condition by spiral connectors or hog rings. Thereafter, the filter fabric layer FL to the interior of the basket NRB is wrapped over the top of the basket, as may be seen from  FIG. 3H .  
         [0041]     The final step, in the completed wall, is shown in  FIG. 3H . As there illustrated, the backfill has been placed and compacted to final grade. This condition is also seen in  FIG. 1 .  
         [0042]     The spiral connector securing the basket TRB to the top of the soil-reinforcing mat SM therebelow is depicted by the numeral  54 , and may be seen from  FIG. 2 . This figure also illustrates how spiral connectors  56  may be used to secure the basket TRB to the longitudinal wires of the soil-reinforcing mat SM.  
         [0043]      FIG. 10  shows one level of a wall comprised of four face members FM and spanning baskets NRB. This staggered arrangement of baskets and face members insures against sloughing between the face members. All levels of the wall beneath the basket TRB are so constructed.  
       Operation  
       [0044]     The wall of the present invention functions to both reinforce the earthen formation and to secure its face against sloughing. Reinforcement is provided by the soil-reinforcing mats SM. Securing on the face against sloughing is provided by the face members FM and the column of rock to the interior thereof provided by the baskets NRB and TRB. These baskets are open to one another and, thus, provide a continuous column of rock at the face of the retained formation. The filter fabric layer FL contains the backfill soil to the interior of the baskets.  
         [0045]     In the event of settling of the earthen formation, the face members FM may move downwardly, as seen in  FIG. 5 . Such downward movement is provided by the slidable interrelationship between the prongs  22  and the wires  12 B at the top of each face member and the slidable interrelationship between the longitudinal wires  14  and the outermost wires  12 B at the bottom of each face member. During such settlement, the face members continue to be secured against outward displacement by both the transverse wires  12 A and  12 B of the soil-reinforcing mats. The transverse wire  16 A of each face member maintains the hook in engagement with the wire  12 A, with the result that downward compression of the face member functions to bend the longitudinal wires in the foot section of the member downwardly, as seen in  FIG. 5 .  
       CONCLUSION  
       [0046]     From the foregoing description, it believed apparent that the present invention enables the attainment of the objects initially set forth herein. In particular, it provides a soil reinforced wall with a rock face wherein the face retaining elements of the wall may accommodate settlement of the earthen formation, without bulging. The number of lifts in the wall may vary, without departing from the invention. The three lift embodiment shown in  FIGS. 1 and 2 , and the four lift embodiment shown in  FIG. 3H , are simply examples. The invention is not intended to be limited by the specifics of the illustrated embodiments, but rather as defined by the accompanying claims.