FIELD OF THE INVENTION
The present invention relates generally to mechanically stabilized earth (MSE) retaining walls and, more particularly, to an improved MSE retaining wall system and method.
BRIEF DESCRIPTION OF THE DRAWINGS
The preferred embodiments of the invention will hereinafter be described in conjunction with the appended drawings provided to illustrate and not to limit the invention, where like designations denote like elements, and in which:
FIG. 1 presents a perspective view of the improved MSE retaining wall system in accordance with the instant invention;
FIG. 2 presents a side elevation, cross-sectional view of the MSE retaining wall system with backfilling;
FIG. 3 presents a perspective view of the MSE retaining wall system in an alternative embodiment used to widen an existing elevated roadway;
FIG. 4 presents a side elevation, cross-sectional view of the MSE retaining wall system used to widen an existing elevated roadway built on top of traditional stabilized earth;
FIG. 5 presents an exploded view of the MSE retaining wall system; and
FIGS. 6 and 7 present anchor straps and dowels used with the MSE retaining wall system.
Like reference numerals refer to like parts throughout the several views of the drawings.
DETAILED DESCRIPTION
The following detailed description is merely exemplary in nature and is not intended to limit the described embodiments or the application and uses of the described embodiments. As used herein, the word “exemplary” or “illustrative” means “serving as an example, instance, or illustration.” Any implementation described herein as “exemplary” or “illustrative” is not necessarily to be construed as preferred or advantageous over other implementations. All of the implementations described below are exemplary implementations provided to enable persons skilled in the art to make or use the embodiments of the disclosure and are not intended to limit the scope of the disclosure, which is defined by the claims. For purposes of description herein, the terms “upper”, “lower”, “left”, “rear”, “right”, “front”, “vertical”, “horizontal”, and derivatives thereof shall relate to the invention as oriented in FIG. 1. Furthermore, there is no intention to be bound by any expressed or implied theory presented in the preceding technical field, background, brief summary or the following detailed description. It is also to be understood that the specific devices and processes illustrated in the attached drawings, and described in the following specification, are simply exemplary embodiments of the inventive concepts defined in the appended claims. Hence, specific dimensions and other physical characteristics relating to the embodiments disclosed herein are not to be considered as limiting, unless the claims expressly state otherwise.
Referring to FIGS. 1 through 7, an improved mechanically stabilizing earth (MSE) retaining wall system 100 (hereinafter the “MSE Wall System”) is generally shown. The MSE Wall System 100 generally comprises a precast base segment 102 and a precast segment that includes a precast riser segment 130 and a precast top segment 160 stackable on top of the precast base segment 102 to construct the MSE wall system 100. Specifically referring to FIGS. 1 and 2, the precast base segment 102 includes an upright wall 104 that is continuous with and extends from a footer 106. As exemplarily shown in FIGS. 1 and 2, the precast base segment 102 generally includes a T-shaped cross-section where the upright wall 104 is substantially extending perpendicular to the footer 106. The upright wall 104 defines opposing side ends 108 and a top end 110. The top end 110 of the upright wall 104 may include one or more voids 112 configured to receive a dowel rod 114. The precast base segment and the precast segments are constructed to include all casting tolerances per the state's Department of Transportation specifications. In one exemplary embodiment, the precast base segment 102 and the precast segments 130, 160 are made out of concrete with a design strength of about 6,500 PSI and a release strength of about 3,250 PSI. If necessary, the segments may include silica fume, metakaolin or ultrafine fly ash. Each segment 102, 130, and 160 may include wire meshing reinforcement, rebar reinforcement, and lifting inserts so that machinery can easily lift each segment. The size of each precast base segment 102 and the precast segments 130 and 160 exceeds 5′×5′ (25 SF) standard panels and are customizable in size (e.g., 5′×15′ (75 SF); or 10′×30′ (300 SF). Securing a precast segment to a precast base segment 102, in one exemplary embodiment, may include but is not limited to grouting the dowel rods 114 of the precast segment into the voids 112 of the precast base segment 102. In one exemplary embodiment, the dowel rod has a 1″ diameter and is FRP smooth, with a minimum shear capacity of 18.5 KIPS. Wall straps 180 that include anchors 182 (FIG. 7) are used when adding backing material 300 against the MSE wall system (FIG. 2). The straps in one exemplary embodiment are made of galvanized metal.
The precast base segment 102 may include a pattern that includes a textured surface 116 with form lines 118 that imitate historical standard wall aesthetics and/or add visual features that include but are not limited to structural elements, architectural elements, design elements, or a combination thereof. In one exemplary embodiment, the form lines are created during the precasting process with the use of a precast mold. The mold includes features that create a permanent texture or patterned surface on the precast segment. The pattern or texture can include, but is not limited to, form lines 118 that imitate historical standard size panels measuring 5′×5′. Put differently, although the precast segments used to construct the improved MSE wall system in the instant invention are larger than a standard panel that is 5′×5′, the precast segment visually will appear that the MSE wall system is made out of standard panels of that size. The footer 106 of the precast base segment 102 is designed and otherwise configured to be disposed on a grade surface 302 and self-support the precast base segment in an upright position as additional precast segments 130, 160 are secured to the precast base segment 102. This is an improvement over traditional wall-building methods that involve using a CIP leveling pad before each base panel is set and strapped/braced into position before additional panels are secured thereto. The improved MSE wall system 100 design and method of use decreases the number of trades involved in completing the work, such as ready-mix trucks and carpenters for formwork, by at least reducing the number of segments needed to build the MSE wall.
With continuous reference to FIGS. 1 and 2, construction of the precast riser segment 130 and the precast top segment 160 differ from the precast base segment 102. For instance, in one exemplary embodiment, the precast riser segment 130 comprises an upright wall 132, including a bottom end 134, opposing side ends 136, and a top end 138. The top end 138 of the wall 132 includes one or more voids 140 configured to receive dowel rods 142. The precast riser segment 130 is designed and configured to be stacked on top of and secured to a precast base segment 102. The precast top segment 160 of the MSE wall system 100 may comprise an upright wall 162, including a bottom end 164, opposing side ends 166, and a top end 168. The precast top segment 160 is securable to a precast riser segment 130 or a precast base segment 102 by using at least dowel rods. Alternative securing methods and components, however, may be used without departing from the scope of the invention. Similarly to the precast base segment 102, the precast riser and top segment 130, 160 may include a textured surface 174, including form lines 176 that imitate historical standard wall aesthetics.
With reference to FIGS. 2, 6 and 7, the MSE wall system 100 may comprise a first MSE wall system 100 and a second MSE wall system 200. This exemplary embodiment can be used, at least in one exemplary embodiment, to widen an existing elevated roadway built on top of traditional stabilized earth. The first MSE wall system 101 may comprise a precast base segment 102, a precast riser segment 130, and a precast top segment 160, as described above. The second MSE wall system 101a may include a precast base segment 102a, a precast riser segment 130a, and a precast top segment 160. The construction of the precast segments 130a, 160a of the second MSE wall system 101a is substantially identical to the construction of the precast segments 130, 160 of the MSE wall system 101a. As such, the precast riser segment 130a comprises an upright wall 132a, including a bottom end, opposing side ends, and a top end 138a. The top end 138a of the wall 132a includes one or more voids 140a configured to receive dowel rods 142a.
The precast top segment 160a of the second MSE wall system 101 may comprise an upright wall 162a, including a bottom end, opposing side ends, and a top end 168a. The precast top segment 160 is securable to a precast riser segment 130a or a precast base segment 102a using at least dowel rods 114a. Unlike the precast base segment 101 of the first MSE wall system, the second MSE wall system 101a includes an upright wall 104a having a bottom end 106a, not a footer, opposing side ends, and a top end 110a. The top end 110a and the bottom end 106a of the upright wall 104a may include one or more voids 112a configured to receive dowel rods 114a to secure a precast segment to the precast base segment 102a and secure the precast base segment 102a to the existing leveling pad 402 of the existing wall.
With reference to FIGS. 4 and 6, the first MSE wall system 101 and the second MSE wall system 101a may be secured to one another with horizontal extending elements, such as dowel rods that are anchored using an anchor 182 to a precast segment (e.g., the precast base, riser, or top segment). To expand the existing elevated roadway, the MSE system 100 is deployed by securing the second MSE wall system 101a to the existing wall system 400 and deploying the first MSE wall system 101 adjacent and substantially in parallel at a desired distance from the second MSE wall system 101a to provide a void 186 in between the first and second MSE wall system 101, 101a. The void 186 is filled with backfilling material 300 to extend the existing elevated roadway.
An exemplary method of constructing the MSE wall system 100 to create an elevated roadway or extend an existing elevated roadway is generally described. In one exemplary method, precast base segments are set along a survey line on a grade surface. The precast riser and precast top segments are subsequently secured to the precast base segments in a pattern. Backfilling material in alternating layers is added between MSE wall systems, and wall straps are anchored to the segments to provide strength, durability, and flexibility to the system. In an exemplary embodiment where the MSE wall system 100 is used to extend an existing roadway, the precast base segments are disposed long a survey line on a grade surface. The bottom ends of the base segments are anchored to the existing wall, and wall segments are added to the wall. Temporary angle brackets are provided to face the existing wall and support the base segments. In one exemplary embodiment, the anchors used are Simpson Titan screw anchors. Backfill material and the installation of the tie-rods are done between the first MSE wall system and the second MSE wall system.
Anchoring of the wall, in some exemplary embodiments, may include but is not limited to drilling voids and using epoxy to set the dowel rods, and installing coil rods and/or threaded rods into the cast-in threaded inserts located in the appropriate face of the segment wall. Couplers may used to make the connections. The method further includes installing vertical angle brackets into the back face of the existing wall and the front face of the anchor wall. Once the upper segment (e.g., riser or top segment) is ready to be set in place with the use of a machine, fill the voids in the base segment with material and insert the protruding dowel rods extending from the segment wall being installed into the voids. Once in place, the vertical angle brace is bolted into the face of the upper segment, and angle brackets are installed into the face of the existing wall and top anchor wall before the upper segment is released from the machine used to set the piece. The above steps are repeated as necessary to achieve the height designed by the construction plans.
The improved MSE wall system, as exemplarily shown in FIG. 5, is modular and utilizes large segments that reduce the number of joints exposed to the mechanically stabilized earth or strata behind the MSE wall system. This results in improved aesthetics and less vegetation growth through the joints formed between each segment, reducing the maintenance requirement for the life of the wall. This is a cost-saving measure for municipalities and states with respect to the maintenance over the life of the wall. The larger wall segments also reduce the time needed with heavy machinery to build the MSE wall system because the larger segments require fewer pieces to be set to cover the same amount of area as conventional wall systems.
Since many modifications, variations, and changes in detail can be made to the described preferred embodiments of the invention, it is intended that all matters in the foregoing description and shown in the accompanying drawings be interpreted as illustrative and not in a limiting sense. Furthermore, it is understood that any of the features presented in the embodiments may be integrated into any of the other embodiments unless explicitly stated otherwise. The scope of the invention should be determined by the appended claims and their legal equivalents.
Patent Application
20250012036
