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 implementation 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 soil reinforcing elements. In most applications, the soil reinforcing elements 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, the soil reinforcing elements can be attached or otherwise coupled to a substantially vertical wall either forming part of the MSE structure or offset a short distance therefrom. The vertical wall is typically made either of concrete or a steel wire facing and not only serves to provide tensile resistance to the soil reinforcing elements but also prevents erosion of the MSE. The soil reinforcing elements extending from the compacted backfill may be attached directly to a vertical wall of the facing in a variety of configurations.
Although there are several methods of attaching soil reinforcing elements to facing structures, it nonetheless remains desirable to find improved attachment methods and systems that provide 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 may include a wire facing having a bend formed therein to form a horizontal element and a vertical facing. The horizontal element may have initial and terminal wires each coupled to a plurality of horizontal wires, and the vertical facing may have a plurality of vertical wires coupled to a plurality of facing cross wires and a top-most cross wire. The mechanically stabilized earth structure may also include a soil reinforcing element having a plurality of transverse wires coupled to at least two longitudinal wires having lead ends that converge, and a connector configured to couple the soil reinforcing element to the wire facing. The connector may include a facing anchor including a plate defining a plate aperture and being integral with or coupled to an extension member configured such that at least a portion of the extension member is inserted through a grid spacing defined by the vertical facing whereby the facing anchor is coupled to the vertical facing. The connector may also include a connective stud including a first end forming a shaft configured to be coupled to the soil reinforcing element and a second end forming a first prong and a second prong, each extending axially from the shaft and offset from the other, such that a gap is defined therebetween. The connector may further include a coupling device configured to couple the facing anchor to the connective stud.
Embodiments of the disclosure may further provide a method of constructing a mechanically stabilized earth structure. The method may include providing a first lift including a first wire facing being bent to form a first horizontal element and a first vertical facing. The first horizontal element may have initial and terminal wires coupled to a plurality of horizontal wires, and the first vertical facing may have 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. The method may also include inserting an extension member of a facing anchor including a plate and the extension member through the first vertical facing, and disposing one or more arms coupled to or integral with the extension member in a substantially horizontal disposition, such that the one or more arms prohibit the extension member from passing back through the first vertical facing. The method may further include coupling a plurality of converging lead ends of longitudinal wires of a first soil reinforcing element to a shaft of a connection stud including a first end forming the shaft and a second end forming a first prong and a second prong, each extending axially from the shaft and further being offset from each other, such that a gap is defined therebetween. The method may also include disposing the plate defining a plate aperture within the gap, such that a first prong opening defined by the first prong and a second prong opening defined by the second prong are each co-aligned with the plate aperture, and inserting a bolt therethrough the co-aligned first prong opening, second prong opening, and plate aperture and coupling a nut to the bolt, such that the facing anchor is coupled to the connection stud. The method may further include placing a screen on the first wire facing whereby the screen covers at least a portion of the first vertical facing and first horizontal element, and placing backfill on the first lift to a first height above the last facing cross wire of the first vertical facing, such that the first height is below the top-most cross wire.
Embodiments of the disclosure may further provide another mechanically stabilized earth structure. The mechanically stabilized earth structure may include a wire facing having a bend formed therein to form a horizontal element and a vertical facing. The horizontal element may have initial and terminal wires each coupled to a plurality of horizontal wires, and the vertical facing may have a plurality of vertical wires coupled to a plurality of facing cross wires and a top-most cross wire. The mechanically stabilized earth structure may also include a soil reinforcing element having a plurality of transverse wires coupled to at least two longitudinal wires having lead ends that terminate substantially parallel to one another, and a connector configured to couple the soil reinforcing element to the wire facing. The connector may include a facing anchor including a continuous wire bent about 180 degrees back about itself about a center section of the continuous wire. The facing anchor may include a coupling section forming a protrusion configured to extend through a grid opening defined by the plurality of transverse wires coupled to the at least two longitudinal wires, and an anchor section including a convergent section formed from the continuous wire converging from the protrusion and a pair of arms extending tangentially from the convergent section. The pair of arms may be configured to be inserted through the vertical facing such that the facing anchor is coupled to the vertical facing. The connector may also include a coupling device configured to be inserted between a spacing defined between the protrusion and the soil reinforcing element, thereby coupling the soil reinforcing element to the facing anchor and the vertical facing.
Embodiments of the disclosure may further provide another method for constructing a mechanically stabilized earth structure. The method may include providing a first lift including a first wire facing being bent to form a first horizontal element and a first vertical facing. The first horizontal element may have initial and terminal wires coupled to a plurality of horizontal wires, and the first vertical facing may have 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. The method may also include applying a force to a convergent section of a facing anchor formed from a continuous wire bent about 180 degrees back about itself about a center section of the continuous wire, the force causing a width of the convergent section to be less than a distance between two adjacent vertical wires of the plurality of vertical wires. The method may further include inserting the facing anchor through the two adjacent vertical wires such that a pair of arms extending tangentially from the convergent section are substantially vertically disposed, and rotating the facing anchor about ninety degrees, such that the pair of arms are substantially horizontally disposed and are further disposed on an opposing side of the vertical facing from a protrusion formed in a coupling section of the facing anchor, such that the arms are prohibited from returning through the two adjacent vertical wires. The method may also include removing the force applied to the convergent section, such that the width of the convergent section is at least substantially equal to the distance between the two adjacent vertical wires, and extending the protrusion through a grid opening formed from a pair of substantially parallel lead ends of longitudinal wires coupled to at least two adjacent transverse wires of a first soil reinforcing element. The method may also include extending a coupling device through a space formed beneath the protrusion and above the pair of substantially parallel lead ends of longitudinal wires such that the soil reinforcing element is coupled to the facing anchor, and placing a screen on the first wire facing whereby the screen covers at least a portion of the first vertical facing and first horizontal element. The method may further include placing backfill on the first lift to a first height above the last facing cross wire of the first vertical facing, such that the first height is below the top-most cross wire.
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. Further, 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
Referring to
The vertical facing 106 can include a plurality of vertical wires 112 extending vertically with reference to the horizontal element 104 and laterally-spaced from each other. In one embodiment, the vertical wires 112 may be vertically-extending extensions of the horizontal wires 108. The vertical facing 106 may also include a plurality of facing cross wires 114 vertically-offset from each other and welded or otherwise attached to the vertical wires 112. A top-most cross wire 116 may be vertically-offset from the last facing cross wire 114 and also attached to the vertical wires 112 in like manner.
In at least one embodiment, each vertical wire 112 may be separated by a distance of about 4 inches on center from adjacent vertical wires 112, and the facing cross wires 114 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 about a 4″×4″ dimension. As can be appreciated, however, the spacing between adjacent wires 112, 114 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 116 may be vertically-offset from the last facing cross wire 114 by a distance X, as will be discussed in more detail below.
The wire facing 102 may further include a plurality of connector leads 111a-g extending from the horizontal element 104 and up the vertical facing 106. In an embodiment, each connector lead 111a-g may include a pair of horizontal wires 108 (or vertical wires 112, if taken from the frame of reference of the vertical facing 106) 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 111a-g may be equidistantly-spaced from each other along the horizontal element 104 and/or vertical facing 106, and configured to provide a visual indicator to an installer as to where a soil reinforcing element 202,202a (FIGS. 1 and 3A-3D) may be properly attached, as will be described in greater detail below. In at least one embodiment, each connector lead 111a-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.
In one or more embodiments, the cross wires 110a-c of the horizontal element 104 may be larger in diameter than the cross wires 114 and top-most cross wire 116 of the vertical facing 106. In at least one embodiment, the cross wires 110a-c of the horizontal element 104 may have diameters at least twice as large as the facing cross wires 114 and top-most cross wire 116 of the vertical facing 106. In other embodiments, however, the diameter of wires 110a-c, 114, 116 may be substantially the same or the facing cross wires 114 may be larger than the cross wires 110a-c of the horizontal element 104 without departing from the scope of the disclosure.
Still referring to
Each strut 118 may be coupled at one end to at least one facing cross wire 114 and at the other end to the terminal wire 110b. In other embodiments, one or more struts 118 may be coupled to the median wire 110c instead of the terminal wire 110b, without departing from the scope of the disclosure. As illustrated, each strut 118 may be coupled to the wire facing 102 in general alignment with a corresponding connector lead 111a-g. In other embodiments, however, the struts 118 can be connected at any location along the respective axial lengths of any facing cross wire 114 and terminal wire 110b, without departing from the scope of the disclosure. In yet other embodiments, the struts 118 may be coupled to a vertical wire 112 of the vertical facing 106 and/or a horizontal wire 108 of the horizontal element 104, respectively, without departing from the scope of the disclosure.
The struts 118 are generally coupled to the wire facing 102 before any backfill 103 (
Referring now to
In one or more embodiments, lead ends 208 of the longitudinal wires 204 of the soil reinforcing element 202 may generally converge and be welded or otherwise attached to a connector 210,310,310a as illustrated in
In at least one embodiment shown in
To secure the soil reinforcing element 202 to a portion of the wire facing 102 (
In embodiments where the lateral spacing of adjacent vertical wires 112 is such that the connector 210 and a portion of the soil reinforcing element 202 may be able to extend through the vertical facing 106, it is further contemplated to employ secondary washers or bearing plates (not shown) on the inside or back side of the vertical facing 106. For instance, at least one secondary washer or bearing plate may extend radially around the threaded rod and be disposed axially adjacent the coil 212 and large enough so as to bear on at least two vertical wires 112 and prevent the connector 210 from passing through the vertical facing 106. Accordingly, the soil reinforcing element 202 may be secured against removal from the wire facing 102 on both front and back sides of the vertical facing 106.
In another embodiment illustrated in
In an exemplary embodiment shown in
As shown in
As illustrated in
Referring to
In another embodiment, the total length T of the arms 324 as extended may be greater than the distance B between the adjacent cross wires 114 through which the arms 324 are extended when vertically disposed. In such an embodiment, a portion (e.g., one of the arms 324) of the arms 324 may be inserted through the spacing between the vertical wires 112 or connector lead 111a from the side of the vertical facing 106 facing the horizontal element 104 (
Conversely, in an exemplary embodiment, the total length T of the arms 324 as extended in the horizontal orientation may be greater than the distance between the vertical wires 112 or connector lead 111a, such that the arms 324 may prohibit the movement of the generally T-shape member 316 from traveling back through the vertical facing 106. As noted above, this distance may vary depending on the particular application, but may generally include about a one inch separation. Embodiments in which the plate 316 may be substantially vertically disposed, inserted between the vertical wires 112 or connector lead 111a from the side of the vertical facing 106 opposing the horizontal element 104, and subsequently rotated about ninety degrees such the plate 314 is horizontally disposed on an opposing side of the vertical facing 106 from the generally T-shape member 316 are also contemplated herein.
Referring to
To secure each of the facing anchors 312a to the vertical facing 106, the generally T-shape member 316a including the arm housing 328 may be inserted between the vertical wires 112 or connector lead 111a from the side of the vertical facing 106 facing the horizontal element 104 (
The arm 324a or anchor pin may be a continuous length of rebar, round stock, a threaded rod, or other similar mechanism conveying similar mechanical properties, configured to be received through each of the bores 330 of the facing anchors 312a. In such a configuration, each of the facing anchors 312a may be connected in tandem. However, it will be appreciated by one of ordinary skill in the art that the plurality of facing anchors 312a may not be interconnected by the arm 324a in one or more embodiments. For example, in another embodiment, each bore 330 may receive a respective arm 324a or anchor pin therethrough, such that each of the respective arms 324a may be greater in length than the distance between the vertical wires 112 or connector lead 111a. As noted above, this distance may vary depending on the particular application, but may generally include about a one inch separation.
In the exemplary embodiments of
As shown in
In the exemplary embodiments of
As secured to the facing anchor 312,312a, the dual-prong connection stud 332 may be free to swivel or rotate about the horizontal plane as denoted by arrow A in
Referring now to another embodiment illustrated in
The folded back continuous wire provides the anchor section 418 with a spring-like characteristic such that the converging section 424 of the anchor section 418 may be moved inward (providing greater convergence) with the application of force and allowed to expand outward (returning to equilibrium) when the force is removed. Accordingly, the converging section 424 of the anchor section 418, in an exemplary embodiment, is substantially equal to or greater in width, W, than the spacing between the vertical wires 112 or connector lead 111a. However, when a force is applied to the converging section 424, the width W may be decreased such that width W is less than the spacing between the vertical wires 112 or connector lead 111a.
Referring to
In such an embodiment, the total length of the arms 426 as extended may be less than the distance B between the adjacent cross wires 114 through which the arms 426 are extended when vertically disposed. As noted above, the distance B may be a distance of about 4 inches on center from adjacent cross wires 114. However, as noted above, the distance B may vary based on the application, and accordingly, the total length of the arms 426 may vary to correspond with the distance B between applicable cross wires 114.
In another embodiment, the total length T of the arms 426 as extended may be greater than the distance B between the adjacent cross wires 114 through which the arms 426 are extended when vertically disposed. In such an embodiment, a portion (e.g., one of the arms 426) of the arms 426 may be inserted through the spacing between the vertical wires 112 or connector lead 111a from the side of the vertical facing 106 facing the horizontal element 104 (
Conversely, in an exemplary embodiment, the total length of the arms 426 as extended in the horizontal orientation may be greater than the distance between the corresponding vertical wires 112 or connector lead 111a, such that the arms 426 may prohibit the movement of the anchor section 418 from traveling back through the vertical facing 106. As noted above, this distance may vary depending on the particular application, but may generally include about a one inch separation.
As shown in
The connector 410 further includes a clasp 428 configured to secure the soil reinforcing element 202a to the facing anchor 412. In an embodiment, the clasp 428 may be manufactured from a continuous length of round-stock iron, plastic, or any similar material with sufficiently comparable tensile, shear, and compressive properties. The clasp 428 may form a generally C-shape including a generally straight clasp middle section 430 connecting a pair of arcuate clasp end sections 432a,b.
To secure the soil reinforcing element 202a to the vertical facing 106, the pair of transverse wires 206 longitudinally offset and disposed at the lead ends 208 of the soil reinforcing element 202a are aligned with the facing anchor 412 such that the crimp 420 is extended through the through the grid opening 422 defined by the lead ends 208 and the longitudinally offset pair of transverse wires 206. The clasp 428 is inserted between the crimp 420 and the lead ends 208 in the spacing defined by the crimp 420 and the lead ends 208 such that the vertical movement of the soil reinforcing element 202a relative to the facing anchor 412 is substantially restricted, thereby coupling the soil reinforcing element 202a to the facing anchor 412 and the vertical facing 106. The horizontal movement of the soil reinforcing element 202a is restricted by the contact of the crimp 420 with the longitudinally offset pair of transverse wires 206 and the lead ends 208.
Referring to
In one or more embodiments, the terminal wire 110b and/or median wire 110c may be located at a predetermined distance from the initial wire 110a to allow at least one transverse wire 206 of the soil reinforcing element 202 to be positioned adjacent the terminal and/or median wires 110b, 110c when the soil reinforcing element 202 is tightened against wire facing 102 with the connector 210. Accordingly, corresponding transverse wires 206 may be coupled or otherwise attached to the terminal and/or median wires 110b, 110c. In at least one embodiment, the transverse wires 206 may be positioned directly behind the terminal and/or median wires 110b, 110c and secured thereto using a coupling device (not shown), such as a hog ring, wire tie, or the like. In other embodiments, however, the transverse wires 206 may be positioned in front of the terminal and/or median wires 110b, 110c and similarly secured thereto with a coupling device, without departing from the scope of the disclosure. In yet other embodiments, the soil reinforcing element 202 is secured to only one or none of the terminal and/or median wires 110b, 110c.
In embodiments where the soil reinforcing element 202 is not coupled to the terminal or median wires 110b, 110c, it may be free to swivel or otherwise rotate in a horizontal plane as generally indicated by arrows A. As can be appreciated, this configuration allows the soil reinforcing elements 202 to swivel in order to avoid vertically-disposed obstructions, such as drainage pipes, catch basins, bridge piles, or bridge piers, which may be encountered in the backfill 103 (
As shown in both
Referring again to
In at least one embodiment, the vertical facings 106 of each lift 105a, 105b may be substantially parallel and continuous, thereby constituting an unbroken vertical ascent for the facing of the MSE structure. In other embodiments, however, the vertical facings 106 of each lift 105a, 105b may be laterally offset from each other. For example, the disclosure contemplates embodiments where the vertical facing 106 of the second lift 105b may be disposed behind or in front of the vertical facing 106 of the first lift 105a, and so on until the desired height of the MSE wall is realized.
In one or more embodiments, because of the added strength derived from the struts 118, each lift 105a, 105b may be free from contact with any adjacent lift 105a, 105b. Thus, in at least one embodiment, the first lift 105a may have backfill placed thereon up to or near the vertical height of the vertical facing 106 and compacted so that the second lift 105b may be placed completely on the compacted backfill of the first lift 105a therebelow. Whereas conventional systems would require the vertical facing 106 of the first lift 105a to be tied into the vertical facing 106 of the second lift 105b to prevent its outward displacement, the present disclosure allows each lift 105a, 105b to be physically free from engagement with each other. This may prove advantageous during settling of the MSE structure. For instance, where adjacent lifts 105a, 105b are not in contact with each other, the system 100 may settle without causing adjacent lifts to bind on each other, which can potentially diminish the structural integrity of the MSE structure.
Referring now to
As shown in
In another embodiment illustrated in
Placing the second lift 105b a distance Y above the upper facing cross wire 114 allows the second lift 105b to vertically shift the distance Y in reaction to MSE settling or thermal expansion/contraction of the MSE structure. Accordingly, the distance Y can be characterized as a distance of settlement over which the second lift 105b may be able to traverse without binding on the first lift 105a and thereby weakening the structural integrity of the MSE system.
Referring now to
The soil reinforcing elements 202 in system 600, however, may include a different type of connector 210,310,310a, than described in system 100. For example, any type of threaded rod can be extended through the coil 212 and secured thereto with a nut 216, thereby replacing the threaded rod 214 as generally described with reference to
In one or more embodiments, the body of the eye-bolt 602 may also be threaded through a second nut 606 adapted to be disposed against the washer 220 on the outside of the vertical facing 106. As illustrated, the body of the eye-bolt 602 can have a non-threaded portion 603 configured to offset the second nut 606 from the head 604 a distance Z when the second nut 606 is fully threaded onto the body. This may allow the head 604 to be laterally-offset from the vertical facing 106, as shown in
As can be appreciated, having the head 604 offset from the vertical facing 106 may provide a location to attach or otherwise form a facing (not shown) to the system 600. For example, rebar may be passed through or otherwise coupled to the heads 604 of each connector 210, thereby providing a skeletal rebar structure prepared to be formed within a facing structure, such as being cast within a concrete skin. Moreover, lengths of rebar may be used to attach turnbuckles or other connection devices configured to couple the vertical facing 106 to a laterally-adjacent facing. As illustrated, the loop or head 604 may be horizontally-disposed, but may also be vertically-disposed without departing from the scope of the disclosure. Consequently, rebar may be passed either vertically or horizontally through adjacent loops or heads 604 in various embodiments of the system 600. Exemplary connective systems that may be used in conjunction with the present disclosure can be found in co-pending U.S. patent application Ser. No. 12/132,750, entitled “Two Stage Mechanically Stabilized Earth Wall System,” filed on Jun. 4, 2008 and hereby incorporated by reference to the extent not inconsistent with the present disclosure.
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. 12/837,347, entitled “Mechanically Stabilized Earth Welded Wire Facing Connection System and Method,” which was filed on Jul. 15, 2010, which in turn is a continuation-in-part of co-pending U.S. patent application Ser. No. 12/818,011, entitled “Mechanically Stabilized Earth System and Method,” which was filed on Jun. 17, 2010. The contents of both applications are hereby incorporated by reference to the extent consistent with the disclosure.
Number | Date | Country | |
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Parent | 12837347 | Jul 2010 | US |
Child | 13457854 | US | |
Parent | 12818011 | Jun 2010 | US |
Child | 12837347 | US |