Patent Application
20130133174
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 applications, the soil reinforcing elements are 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 structure. The soil reinforcing elements extend from the compacted backfill and are attached to the vertical wall in a variety of configurations. For instance, facing anchors can be embedded in the vertical wall and thereby provide a connection point where the soil reinforcing elements can be attached. Each facing anchor is typically positioned so as to correspond with and couple directly to an end of a soil reinforcing element.
A defective connection between the facing anchor and the soil reinforcing element will reduce the structural integrity of the MSE structure. Consequently, ensuring that the connection is secure is a vital step in making certain the MSE structure will be able to endure several years of effective use.
What is needed is a connection apparatus or device for connecting a soil reinforcing element to a facing anchor that readily indicates when a proper connection has been made.
Embodiments of the disclosure may provide a drive pin mechanical fastener. The drive pin mechanical fastener may include an elongate body extending from a head, and an indicator shroud having a first end and a second end, the first end being disposed about the elongate body proximate the head and the second end extending away from the head, the indicator shroud being movable from a first position, where the indicator shroud is frustoconical, to a second position, where the indicator shroud is flattened.
Embodiments of the disclosure may further provide a connection assembly for a soil reinforcing element. The connection assembly may include a facing anchor having first and second offset prongs, each prong having a hole defined therein, and a connection stud coupled to the soil reinforcing element and having a tab that defines a tab hole therein, the tab being positioned between the first and second prongs such that the tab hole may be concentrically-aligned with the holes in the first and second prongs. The connection assembly may also include a mechanical fastener having an elongate body extending from a head and through the holes defined in the prongs and the tab hole, and an indicator shroud having a first end and a second end, the first end being disposed about the body proximate the head of the mechanical fastener and the second end extending away from the head. The mechanical fastener may be configured to move from a first position, where the indicator shroud is frustoconical, to a second position, where the indicator shroud is flattened and extends radially-outward from the head such that the indicator shroud as flattened is visible from a top perspective.
Embodiments of the disclosure may further provide a method of securing a soil reinforcing element to a facing anchor. The method may include positioning a tab between first and second prongs of the facing anchor, the tab being coupled to the soil reinforcing element and having a tab hole defined therein, and aligning the tab hole with concentric holes defined in the first and second prongs. The method may also include inserting a drive pin body through the concentric holes of the first and second prongs and simultaneously through the tab hole, the drive pin body extending from a head and having a first series of teeth formed thereon adjacent the head, and forcing the drive pin body through the hole defined in the first prong such that the first series of teeth form an interference fit therein. The method may further include flattening an indicator shroud disposed about the drive pin body adjacent the head such that portions of the frustoconical indicator shroud are exposed radially-outward from the head and thereby provide a visual indication that the drive pin is properly secured.
Embodiments of the disclosure may further provide a drive pin mechanical fastener. The drive pin mechanical fastener may include an elongate body extending from a head and a sleeve at least partially encasing the elongate body. The drive pin mechanical fastener may also include a plurality of serrations defined at a distal end of the sleeve, such that the plurality of serrations are deformable, but resilient, such that the plurality of serrations are adapted to pass through one or more holes defined in a facing anchor and rebound to prevent the mechanical fastener from removal from the facing anchor.
Embodiments of the disclosure may further provide a drive pin mechanical fastener. The drive pin mechanical fastener may include an elongate body extending from a head, and a first series of teeth formed on the elongate body proximate the head and extending at least partially around a circumference of the elongate body, the first series of teeth having an outer diameter greater than a diameter of the elongate body and extending axially along an axial length of the body.
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
Cast into the facing 102, or otherwise attached thereto, and protruding generally from the back face 106, is at least one exemplary facing anchor 108. In other embodiments, the facing anchor 108 may be mechanically-fastened to the back face 106, for example, using bolts or other mechanical fasteners. In yet other embodiments, the facing anchor 108 may be inserted into a hole drilled into the back face 106 and secured therein with epoxy, concrete, construction adhesive, combinations thereof, or the like.
It will be appreciated that the illustrated facing anchor 108 is merely exemplary and should not be limited to the embodiments shown herein, as other types of facing anchors are also contemplated without departing from the scope of the disclosure. Several exemplary embodiments of the facing anchor 108, and a range of variations thereof, are found in co-pending U.S. patent application Ser. No. 12/756,898, entitled “Retaining Wall Soil Reinforcing Connector and Method,” the contents of which are hereby incorporated by reference to the extent consistent with this disclosure.
The illustrated facing anchor 108 may be characterized as a dual-prong stud anchor, having an elongated shaft 110 terminating at a head 112 at one end and a pair of offset connection points or prongs 114a, 114b extending axially from the other end. The head 112 may be omitted from the shaft 110 in one or more embodiments without departing from the scope of the disclosure. Each prong 114a,b defines a centrally-disposed hole 116 and is offset by a distance X, thereby creating a gap 118 between the prongs 114a,b. The gap 118 provides a location for connecting a soil reinforcing element 140 to the facing anchor 108. A series of indentations or grooves 120 may be defined along the axial length of the shaft 110. The grooves 120 may help prevent removal of the facing anchor 108 from the facing 102 by providing a stronger bond and/or frictional engagement with the concrete, adhesive, epoxy, etc., within the facing 102.
The earthen formation 104 may encompass an MSE structure including a plurality of soil reinforcing elements 140 that extend horizontally into layers of backfill material. The soil reinforcing elements 140 serve as tensile resisting elements strategically-positioned in the backfill in a substantially horizontal alignment at spaced-apart relationships to one another against the compacted backfill material.
The exemplary soil reinforcing element 140 is a welded wire grid having a pair of longitudinal wires 142 that extend substantially parallel to each other. The longitudinal wires 142 are joined to a plurality of transverse wires 144 in a generally perpendicular fashion by welds at their intersections, thus forming a welded wire gridwork. In exemplary embodiments, the spacing between each longitudinal wire 142 may be about 2 in., while spacing between each transverse wire 144 may be about 6 in. As can be appreciated, however, the relative spacing and configuration may vary depending on the mixture of tensile force requirements that the reinforcing element 140 must resist.
In one or more embodiments, the lead ends 146 of the longitudinal wires 142 generally converge toward one another and are welded or otherwise attached to a connection stud 130. The connection stud 130 may have a stem 132 (first end) extending from a tab 134 (second end), where the lead ends 146 are coupled to the stem 132. The tab 134 may be a substantially planar plate that defines at least one centrally-located perforation or hole 136 defined therethrough. As with the facing anchor 108, it will be appreciated that the connection stud 130 is only exemplary and should not be limited to the embodiments shown and described herein. For example, several exemplary embodiments of the connection stud 130, and a range of variations thereof, are found in co-pending U.S. patent application Ser. No. 13/100,927, entitled “Retaining Wall Soil Reinforcing Connector and Method,” the contents of which are also hereby incorporated by reference to the extent consistent with this disclosure.
A drive pin mechanical fastener 150 is used to couple the facing anchor 108 to the connection stud 130. Referring to
The body 154 is adapted to be inserted through the concentric holes 116 of each prong 114a,b, and simultaneously through the hole 136 defined in the tab 134 in order to couple the facing anchor 108 to the connection stud 130. A first series of seating teeth 168 may be disposed around or otherwise formed on the body 154 proximate its first end 160. The teeth 168 may be generally defined axially along the axial length of the body 154 and extend around the all or a portion of the circumference of the body 154. The teeth 168 may have an outer diameter 170 that is slightly greater than the outer circumference or diameter 166 of the body 154 and also slightly greater than the diameter of the holes 116 in the prongs 114a,b. Thus, as the body 154 is inserted or otherwise forced into the hole 116 of the first prong 114a, the teeth 168 provide an interference or friction fit with the prong 114a. Consequently, the mechanical fastener 150 is secured to the facing anchor 108, and the facing anchor 108 is secured to the connection stud 130.
As shown in
The shoulder surface 158 has a diameter 164 greater than the diameter 166 of the body 154 such that the fastener 150a,b is prevented from passing entirely through the holes 116. Accordingly, once the shoulder surface 158 engages the first prong 114a, the body 154 is prevented from any further advancement.
An elongate indicator shroud 180 is disposed at least partially around the body 154 and extends radially-outward from the first series of teeth 168. The indicator shroud 180 is made of a deformable or malleable material, such as, but not limited to, plastics or soft metals. A first end 182 of the indicator shroud 180 is coupled to or otherwise seated at the first end 160 of the body 154 and extends to a second end 184 in a generally frustoconical shape. Consequently, the diameter of the first end 182 of the indicator shroud 180 is generally smaller than the diameter of the second end 184 of the indicator shroud 180.
Referring now to
Driving the fastener 150a into the holes 116 may generally flatten the indicator shroud 180 between the shoulder surface 158 of the mechanical fastener 150 and the first prong 114a. In at least one embodiment, the indicator shroud 180 may tear at one or more locations 189a and 189b, thereby exposing one or more portions 190a and 190b of the indicator shroud 180 which extend radially-outward from the head 152. The portions 190a,b of the indicator shroud 180 may be seen from above, such as from the vantage point of an installer or site worker. Consequently, the exposed portions 190a,b may provide a visual indicator that the mechanical fastener 150a is properly engaged, thereby allowing the installer or site worker to proceed to the next connection point.
Once coupled to the facing anchor 108, the connection stud 130 may be able to swivel or rotate about axis Y (
Moreover, the gap 118 defined between two prongs 114a,b may allow for a distance of settling of either the MSE structure or the soil reinforcing element 140 without the soil reinforcing element 140 binding on the facing 102. For instance, during settling the tab 134 may be able to shift or slide vertically about the mechanical fastener 150 the distance X, thereby compensating for a potential vertical drop of the soil reinforcing element 140 and preventing the concrete facing 102 from buckling. Varying designs of anchors 108 may be used that increase or decrease the distance X to compensate for potential settling or other MSE mechanical phenomena. Furthermore, it is not uncommon for concrete facings 102 to shift in reaction to MSE settling or thermal expansion/contraction. In instances where such movement occurs, the soil reinforcing elements 140 are capable of correspondingly swiveling about axis Y and shifting the vertical distance X to prevent misalignment, buckling, or damage to the concrete facing 102.
Referring now to
Unlike the fasteners 150a,b described above, the body 154 of the fastener 702 may be at least partially encased in an elongate sleeve 704. The sleeve 704 may be made from a variety of materials including, but not limited to, plastics, metals, or other flexible or semi-flexible materials. In other embodiments, the sleeve 704 forms an integral part of the fastener 702, such that the sleeve 704 and the fastener 702 are made of the same material in the same monolithic structure.
In one embodiment, the sleeve 704 is sized slightly larger than the holes 116 of the prongs 114a,b (
A plurality of barbs or serrations 706 may be defined at a distal end 708 of the sleeve 704. The serrations 706 are deformable, but resilient, such that as the serrations 706 pass through the holes 116 they rebound and prevent the fastener 702 from reversing direction back through the holes 116. In one embodiment, the body 154 is also threaded at the second end 162 so that a nut (not shown) can be threaded thereon to secure the fastener against removal.
The fastener 702 may also include a lever point 710 defined adjacent the head 152, but above the indicator shroud 180. The lever point 710 may be sized larger than the holes 116 such that the fastener 702 is prevented from passing all the way through the holes 116 by the lever point 710. As the fastener 702 is driven through the holes 116, the indicator shroud 180 operates as generally described above to indicate when the fastener 702 is properly installed. The lever point 710 extends above the flattened indicator shroud 180 in the engaged position and provides a location where the fastener 702 may be removed from the anchor 108. Specifically, the lever point 710 may provide a gap between the head 152 and the first prong 114a in the engaged position such that a type of prying device, such as a pry bar or the claw of a hammer, may be inserted into the gap in order to lever the fastener 702 from its engaged position. It will be appreciated that the lever point 710 may also be used or otherwise defined on the mechanical fasteners 150a,b described above.
Referring now to
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.
