Retaining wall structures that use horizontally positioned soil inclusions to reinforce an earth mass in combination with a facing element are referred to as Mechanically Stabilized Earth (MSE) structures. MSE structures can be used for various applications including retaining walls, bridge abutments, dams, seawalls, and dikes.
The basic MSE technology is a repetitive process where layers of backfill and horizontally placed soil reinforcing elements are positioned one atop the other until a desired height of the earthen structure is achieved. Typically, grid-like steel mats or welded wire mesh are used as earthen reinforcement elements. In most applications, the reinforcing mats consist of parallel transversely extending wires welded to parallel longitudinally extending wires, thus forming a grid-like mat or structure. Backfill material and the soil reinforcing mats are combined and compacted in series to form a solid earthen structure, taking the form of a standing earthen wall.
In some instances, a substantially vertical wall, typically made of concrete or steel facing panels, may then be constructed a short distance from the standing earthen wall. The vertical wall not only serves as decorative architecture, but also prevents erosion at the face of the earthen wall. The soil reinforcing mats extending from the compacted backfill may then be attached directly to the back face of the vertical wall in a variety of configurations. To facilitate the connection to the earthen formation, the vertical wall will frequently include a plurality of “facing anchors” either cast into or attached somehow to the back face of the wall at predetermined and/or spaced-apart locations. Each facing anchor is typically positioned so as to correspond with and couple directly to the end of a soil reinforcing mat. Via this attachment, outward movement and shifting of the vertical wall is significantly reduced.
Although there are several methods of attaching soil reinforcing elements to facing structures, it nonetheless remains desirable to find improved anchors and anchor-designs offering less expensive alternatives and greater resistance to shear forces inherent in such structures.
Embodiments of the disclosure may provide a mechanically stabilized earth structure. The mechanically stabilized earth structure includes a wire facing having a bend formed therein to form a horizontal element and a vertical facing, the horizontal element having initial and terminal wires each coupled to a plurality of horizontal wires, and the vertical facing having a plurality of vertical wires coupled to a plurality of facing cross wires and a top-most cross wire. The mechanically stabilized earth structure also includes a soil reinforcing element having a plurality of transverse wires coupled to at least two longitudinal wires having upwardly-extending extensions, and a connection device having a bearing plate with one or more longitudinal protrusions configured to receive the upwardly-extending extensions, the connection device being configured to couple the soil reinforcing element to the vertical facing.
Other embodiments of the disclosure may provide a mechanically stabilized earth structure. The mechanically stabilized earth structure includes a first lift which includes a first wire facing having a first horizontal element and a first vertical facing, the first horizontal element having initial and terminal wires coupled to a plurality of horizontal wires, and the first vertical facing having a plurality of vertical wires coupled to a plurality of facing cross wires including a last facing cross wire and a top-most cross wire vertically-disposed above the last facing cross wire. The first life also includes a first soil reinforcing element having a plurality of transverse wires coupled to at least two longitudinal wires having upwardly-extending extensions, and a first connection device having a first bearing plate with one or more longitudinal protrusions configured to receive the upwardly-extending extensions of the first soil reinforcing element, the first connection device being configured to couple the soil reinforcing element to the first vertical facing. The first life also includes backfill disposed on the first wire facing to a first height above the last facing cross wire of the first vertical facing. The mechanically stabilized earth structure also includes a second lift disposed on the backfill of the first lift, the second lift, which includes a second wire facing having a second horizontal element and a second vertical facing, and a second soil reinforcing element disposed on the second horizontal element and having a plurality of transverse wires coupled to at least two longitudinal wires having upwardly-extending extensions. The second lift also includes a second connection device having a second bearing plate with one or more longitudinal protrusions configured to receive the upwardly-extending extensions of the second soil reinforcing element, the second connection device being configured to couple the second soil reinforcing element to the first and second vertical facings.
Other embodiments of the disclosure may also provide a method of constructing a mechanically stabilized earth structure. The method includes providing a first lift includes a first wire facing bent to form a first horizontal element and a first vertical facing, the first vertical facing having a plurality of vertical wires coupled to a plurality of facing cross wires including a last facing cross wire and a top-most cross wire vertically-disposed above the last facing cross wire. The method also includes placing a first quantity of backfill on the first lift to a first height above the first horizontal element, and coupling a first soil reinforcing element to the first vertical facing at the first height and on top of the first quantity of backfill. The method further includes placing a second quantity of backfill atop the first quantity of backfill and the first soil reinforcing element to a second height above the last facing cross wire of the first vertical facing, and disposing a second lift atop the first lift, the second lift includes a second wire facing bent to form a second horizontal element and a second vertical facing, the second vertical facing having a plurality of vertical wires coupled to a plurality of facing cross wires including a last facing cross wire and a top-most cross wire vertically-disposed above the last facing cross wire. The method also includes placing a third quantity of backfill on the second lift to a third height above the second horizontal element, and coupling a second soil reinforcing element to the second vertical facing at the third height and on top of the third quantity of backfill. The method further includes placing a fourth quantity of backfill atop the third quantity of backfill and the second soil reinforcing element to a fourth height above the last facing cross wire of the second vertical facing.
The present disclosure is best understood from the following detailed description when read with the accompanying Figures. It is emphasized that, in accordance with the standard practice in the industry, various features are not drawn to scale. In fact, the dimensions of the various features may be arbitrarily increased or reduced for clarity of discussion.
It is to be understood that the following disclosure describes several exemplary embodiments for implementing different features, structures, or functions of the invention. Exemplary embodiments of components, arrangements, and configurations are described below to simplify the present disclosure; however, these exemplary embodiments are provided merely as examples and are not intended to limit the scope of the invention. Additionally, the present disclosure may repeat reference numerals and/or letters in the various exemplary embodiments and across the Figures provided herein. This repetition is for the purpose of simplicity and clarity and does not in itself dictate a relationship between the various exemplary embodiments and/or configurations discussed in the various Figures. Moreover, the formation of a first feature over or on a second feature in the description that follows may include embodiments in which the first and second features are formed in direct contact, and may also include embodiments in which additional features may be formed interposing the first and second features, such that the first and second features may not be in direct contact. Finally, the exemplary embodiments presented below may be combined in any combination of ways, i.e., any element from one exemplary embodiment may be used in any other exemplary embodiment, without departing from the scope of the disclosure.
Additionally, certain terms are used throughout the following description and claims to refer to particular components. As one skilled in the art will appreciate, various entities may refer to the same component by different names, and as such, the naming convention for the elements described herein is not intended to limit the scope of the invention, unless otherwise specifically defined herein. Further, the naming convention used herein is not intended to distinguish between components that differ in name but not function. Additionally, in the following discussion and in the claims, the terms “including” and “comprising” are used in an open-ended fashion, and thus should be interpreted to mean “including, but not limited to.” All numerical values in this disclosure may be exact or approximate values unless otherwise specifically stated. Accordingly, various embodiments of the disclosure may deviate from the numbers, values, and ranges disclosed herein without departing from the intended scope. Furthermore, as it is used in the claims or specification, the term “or” is intended to encompass both exclusive and inclusive cases, i.e., “A or B” is intended to be synonymous with “at least one of A and B,” unless otherwise expressly specified herein.
Referring to
In one or more embodiments, the facing anchor assembly 100 may be configured to receive and secure a soil reinforcing element 114 (
As illustrated in
The coupling perforations 108 of each plate 102 may be used to secure one or more transverse wires 118 within the transverse protrusions 106, thereby generally securing the soil reinforcing element 114 to the plates 102. For example, as illustrated in
As can be appreciated, securing the first and second transverse wires 118a,b within the transverse protrusions 106 may equally distribute shear stresses along the length of the transverse wires 118a,b, instead of focusing shear forces at a singular weld point. Moreover, clamping the longitudinal wires 116 between the plates 102 may distribute tensile forces between each longitudinal wire 116, instead of relying on a single wire during shifting of the MSE structure.
Referring to
In at least one embodiment, a portion of the facing anchor assembly 100, and more particularly the plates 102, may be cast directly into the facing 126 to secure the assembly 100 against removal. As illustrated, the tabs 104 of each plate 102 may be part of the portion cast into the facing 126 and may serve to provide rigidity and stability to the resulting connection. The plates 102 may be cast into the facing 126 so as to be vertically-offset from each other and define a gap adapted to accommodate the receipt of a soil reinforcing element 114. In operation, the gap defined between adjacent plates 102 may generally flex to allow entry of a soil reinforcing element 114.
In another exemplary embodiment, the plates 102 may not be cast into the facing 126, but may be bolted, or otherwise attached, directly to the back face 130. For example, holes may be drilled into the back face 130 of the concrete facing 126 to correspond to the facing perforations 110 defined on each tab 104. A bolt and washer assembly (not shown), or other connective means, may be used to secure the plates to the back face 130.
Referring now to
Referring now to
As illustrated, the transverse protrusion 308 of the top plate 302 may receive the first transverse wire 118a, but in other exemplary applications the transverse wires 118 may be located on the underside of the soil reinforcing element 114, thus the first transverse wire 118a may be captured and seated within the transverse protrusions 308 of the opposing bottom plate 302. Moreover, other applications (not specifically illustrated herein) may include soil reinforcing elements 114 with transverse wires 118 attached to both the top and the bottom of the longitudinal wires 116, thereby seating transverse wires 118 in the transverse protrusion 308 of each plate 302.
A coupling assembly 310 can be used to clamp the longitudinal wires 116 between the plates 302, thereby creating a frictional or biasing engagement configured to prevent the removal of the soil reinforcing element 114 from the facing anchor assembly 300. Clamping the longitudinal wires 116 between the plates 302 may also securely seat the first transverse wire 118a within the transverse protrusion 308, thereby distributing shear stresses equally along the length of the transverse wire 118a and further preventing the removal of the first transverse wire 118a from the facing anchor assembly 300.
Referring now to
In the illustrated exemplary embodiment, the plates 102 of the facing anchor assembly 100 can be cast into the back face 130 of the facing 126, similar to the embodiment discussed above with reference to
Referring now to
As illustrated, the swiveling facing anchor 500 may generally include the facing anchor assembly 100, as described above, but may also include a swivel plate 502 and a retainer plate 508. The swivel plate 502 may have a first transverse protrusion 504 and a second transverse protrusion 506 for seating and securing first and second transverse wires 118a,b. As can be appreciated, other embodiments may include a swivel plate 502 having more or less transverse protrusions 506 to fit a variety of applications. The retainer plate 508 may include a first elevation 507 at a first end bound in conjunction with the facing anchor assembly 100, and a second elevation 509 at a second end bound in conjunction with the swivel plate 502. In at least one embodiment, the retainer plate 508 may be configured to provide a binding surface where the longitudinal wires 116 of the soil reinforcing element 114 can be clamped into biasing engagement with swivel plate 502. In other exemplary embodiments, the retainer plate 508 may simply include the second elevation 509 to provide the binding or biasing engagement to the longitudinal wires 116, without departing from the scope of the disclosure.
The swiveling facing anchor may further include a first coupling assembly 510 and a second coupling assembly 518. The first coupling assembly 510 may be used to couple the facing anchor assembly 100 to both the swivel plate 502 and the retainer plate 508. In at least one embodiment, the first coupling assembly 510 may include a bolt 511 and nut 516 assembly having a washer disposed at each end, but may also include other means of mechanical coupling without departing from the scope of the disclosure. In an exemplary embodiment, the bolt 511 may be extended through the coupling perforation 108 defined in each plate 102 and also extended through separate concentric perforations 512,514 defined in both the swivel plate 502 and the retainer plate 508, respectively. The nut 516 may be tightened onto the bolt 511 to secure the swivel plate 502 and the retainer plate 508 from removal.
The second coupling assembly 518 may be substantially similar to the first coupling assembly 510 and may be used to couple the swivel plate 502 to the retainer plate 508, and also may serve to seat the first and second transverse wires 118a,b within the first and second transverse protrusions 504,506, respectively. As described above, coupling the swivel plate 502 to the retainer plate 508 may also provide a binding engagement to the longitudinal wires 116 of the soil reinforcing element 114. A bolt 520 of the second coupling assembly 518 may be extended through a coupling perforation 522 defined in the swivel plate 502, and also extended through a retainer perforation 524 defined in the retainer plate 508. A nut 526 may be tightened onto the bolt 520 to effectively clamp down on the longitudinal wires 116, thereby creating a frictional engagement configured to prevent the removal of the soil reinforcing element 114.
Referring to
Referring now to
In at least one embodiment, the exemplary facing anchor 600 may be a device capable of receiving and securely seating one or more transverse wires 118 of the soil reinforcing element 114, and simultaneously connecting the soil reinforcing element 114 to at least one horizontal wire 606 (
Each side 608, 610 may define two transverse protrusions 614. However, other exemplary embodiments may define more or less than two transverse protrusions 614 to thereby fit other applications. A coupling perforation 616 and a trough 618 may also be defined on each side 608, 610. In embodiments having two transverse protrusions 614, as illustrated, the coupling perforation 616 of each side 608, 610 may be concentrically defined therebetween. Thus, in at least one embodiment, the first and second sides 608, 610 of the facing anchor 600 can be mirror images of each other.
Referring to
Similar to the coupling assemblies 122, 310, 510, 518 described above, a coupling assembly 620 (
Referring to
Referring now to
Each lift 702a,b may include a wire facing 706 having one or more soil reinforcing elements 708 coupled thereto. Similar to the soil reinforcing element 114 described above, the soil reinforcing element 708, as shown in FIGS. 7A and 8A-8C, may include a wire grid having at least two longitudinal wires 116 disposed substantially parallel to each other, and a series of transverse wires 118 welded or otherwise attached to the longitudinal wires 116 in a generally perpendicular fashion. Each longitudinal wire 116, however, may include an upwardly-extending extension 709 disposed at its lead end. In one embodiment, each extension 709 may be disposed at about 90° with respect to the longitudinal wires 116. In other embodiments, however, each extension 709 may be configured at greater or less than 90° with respect to the longitudinal wires 116.
One or more struts 710 may also be coupled to each wire facing 706 and adapted to maintain the wire facing 706 in a predetermined angular configuration. The backfill 704 may be sequentially added to the system 700 in a plurality of layers configured to cover the soil reinforcing elements 708, thereby providing tensile strength to each wire facing 706 and preventing their outward displacement.
The vertical facing 714 can include a plurality of vertical wires 720 extending vertically with reference to the horizontal element 712 and laterally-spaced from each other. In one embodiment, the vertical wires 720 may be vertically-extending extensions of the horizontal wires 716. The vertical facing 714 may also include a plurality of facing cross wires 722 vertically-offset from each other and welded or otherwise attached to the vertical wires 720. A top-most cross wire 724 may be vertically-offset from the last facing cross wire 722 and also attached to the vertical wires 720 in like manner.
In at least one embodiment, each vertical wire 720 may be separated by a distance of about 4 inches on center from adjacent vertical wires 720, and the facing cross wires 722 may also be separated from each other by a distance of about 4 inches on center, thereby generating a grid-like facing composed of a plurality of square voids having a 4″×4″ dimension. As can be appreciated, however, the spacing between adjacent wires 720, 722 can be varied to more or less than 4 inches to suit varying applications and the spacing need not be equidistant. In one embodiment, the top-most cross wire 724 may be vertically-offset from the last facing cross wire 722 by a distance X, as will be discussed in more detail below.
The wire facing 706 may further include a plurality of connector leads 726a-g extending from the horizontal element 712 and up the vertical facing 714. In an embodiment, each connector lead 726a-g may include a pair of horizontal wires 716 (or vertical wires 720, if taken from the frame of reference of the vertical facing 714) laterally-offset from each other by a short distance. The short distance can vary depending on the particular application, but may generally include about a one inch separation. In one embodiment, each connector lead 726a-g may be equidistantly-spaced from each other along the horizontal element 712 and/or vertical facing 714, and configured to provide a visual indicator to an installer as to where a soil reinforcing element 708 may be properly attached, as will be described in greater detail below. In at least one embodiment, each connector lead 726a-g may be spaced from each other by about 12 inches on center. As can be appreciated, however, such relative distances may vary to suit particular applications.
Still referring to
Each strut 710 may be coupled at one end to at least one facing cross wire 722 and at the other end to the terminal wire 718b. In other embodiments, one or more struts 710 may be coupled to the median wire 718c instead of the terminal wire 718b, without departing from the scope of the disclosure. As illustrated, each strut 710 may be coupled to the wire facing 706 in general alignment with a corresponding connector lead 726a-g. In other embodiments, however, the struts 710 can be connected at any location along the respective axial lengths of any facing cross wire 722 and terminal wire 718b, without departing from the scope of the disclosure. In yet other embodiments, the struts 710 may be coupled to a vertical wire 720 of the vertical facing 714 and/or a horizontal wire 716 of the horizontal element 712, respectively, without departing from the scope of the disclosure.
The struts 710 are generally coupled to the wire facing 706 before any backfill 704 (
Referring now to
In one or more embodiments, the connection device 730 may include at least one bearing plate 732 having one or more longitudinal protrusions 740 configured to receive or otherwise seat the upwardly-extending extensions 709 of the soil reinforcing element 708 when installed in the system 700. As can be appreciated, in embodiments having more than two longitudinal wires 116, with corresponding more than two upwardly-extending extensions 709, there may be a corresponding number of longitudinal protrusions 740 to accommodate each extension 709. The longitudinal protrusions 740 may serve to centralize the soil reinforcing element 708 with respect to the bearing plate 732 and prevent the soil reinforcing element 708 from shifting or otherwise moving from side to side. This may prove advantageous during settling and/or thermal contraction and expansion of the MSE structure where the soil reinforcing element 708 may otherwise become dislodged from the system 700 and thereby weaken the structural integrity of the MSE structure.
The bearing plate 732 may be configured to accommodate or otherwise receive a rod 734, such as a threaded rod, via a perforation (not shown) centrally-defined within the bearing plate 732. In at least one embodiment, the rod 734 may be a bolt, but may also be a length of rebar or other rigid material. The rod 734 may be configured to extend through the perforation (not shown) of the bearing plate 732 and further through any adjacent vertical facings 714, such as vertical facings 714a,b, as best seen in
As illustrated, the connection device 730 may be coupled to the vertical facings 714a,b at a connector lead 726a-g, such as connector lead 726a as shown in
In exemplary operation, with continued reference to
According to embodiments disclosed herein, the connection device 730 may be configured to not only couple a soil reinforcing element 708 to a single vertical facing 714 or a pair of vertical facings 714a,b, but it may also facilitate a sliding or slidable engagement between adjacent lifts 702a and 702b. In order to ensure a sliding engagement between the first and second lifts 702a,b, the nut 736 may be “finger-tightened,” or tightened so as to nonetheless allow vertical movement of either the first or second lift 702a,b with respect to each other. Tightening the nut 736 may bring the bearing plate 732 and/or upwardly-extending extensions 709 into engagement with the vertical facing 714b of the second lift 702b, having the soil reinforcing element 708 resting on or at least adjacent the initial wire 718a. Tightening the nut 736 may also bring the washer 738 into engagement with the vertical facing 714a of the first lift 702a, as discussed above. In at least one embodiment, tightening the nut 736 may further bring the top-most cross wire 724 of the first vertical facing 714a into engagement with the second vertical facing 714b and thereby further prevent the outward displacement of the second vertical facing 714b. However, in other embodiments, the top-most cross wire 724 is not necessarily brought into contact with the second vertical facing 714b, but the second vertical facing 714b may be held in its angular configuration by the strut 118 and connection device 120 disposed on the last facing cross wire 722.
Placing the second lift 702b a distance Y above the last facing cross wire 722 allows the second lift 702b to vertically shift the distance Y in reaction to MSE settling or thermal expansion/contraction of the MSE structure before coming into contact with the last facing cross wire 722 and potentially the strut 710 of the first lift 702a. Accordingly, the distance Y can be characterized as a distance of settlement over which the second lift 702b may be able to traverse without binding on the first lift 702a and thereby weakening the structural integrity of the MSE system.
Referring now to
A second quantity of backfill 704b may then be placed atop the first quantity of backfill 704a to a second height Y above the last facing cross wire 722. As shown in
As shown in
The second lift 702b may be constructed substantially similar to the first lift 702a, but may also include one or more struts 710 as described above. While not specifically shown in
After the optional placement of the strut 710, a third quantity of backfill 704c may be placed on the second horizontal element 712b of the second lift 702b to a third height Q above the second horizontal element 712b. The first and third height Q may be substantially similar, but may otherwise differ, depending on the application. After a soil reinforcing element 708 is placed atop the compacted third quantity of backfill 704c and coupled to the second vertical facing 714b with a connection device 730, a fourth portion of backfill 704d may be added and compacted. The fourth quantity of backfill 704d may be added atop the third quantity of backfill 704c to a fourth height Y above the last facing cross wire 722 of the second vertical facing 714b. The second and fourth height Y may be substantially similar, but may otherwise differ, depending on the application.
Referring to both
The foregoing has outlined features of several embodiments so that those skilled in the art may better understand the present disclosure. Those skilled in the art should appreciate that they may readily use the present disclosure as a basis for designing or modifying other processes and structures for carrying out the same purposes and/or achieving the same advantages of the embodiments introduced herein. Those skilled in the art should also realize that such equivalent constructions do not depart from the spirit and scope of the present disclosure, and that they may make various changes, substitutions and alterations herein without departing from the spirit and scope of the present disclosure.
The present application is a continuation-in-part of co-pending U.S. patent application Ser. No. 12/684,479, entitled “Wave Anchor Soil Reinforcing Connector and Method,” which was filed on Jan. 8, 2010, the contents of which are incorporated herein by reference in its entirety.
Number | Date | Country | |
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Parent | 12684479 | Jan 2010 | US |
Child | 12861632 | US |