MSE WALL GUARDRAIL SYSTEM

Abstract

Guardrail support brackets for use in securing safety guardrails during the construction of MSE wall systems. The guardrail support brackets include a clamping portions that secure the support brackets to the top of adjacent wall panels, vertical support posts that are coupled to the clamping portions in such a manner to allow the vertical support posts to extend above or below the clamping portions, and guardrail supports that secure elongate guardrail elements to the vertical support posts.

Description

RELATED APPLICATION

This application is based on U.S. Provisional Application Ser. No. 61/781,209, filed Mar. 14, 2013 to which priority is claimed under 35 U.S.C. §120.

BACKGROUND

The present invention relates generally to guardrail systems for construction sites and more particularly to guardrail systems for use in the construction of mechanical stabilized earth (MSE) walls.

Mechanically stabilized earth (MSE) is soil constructed with artificial reinforcing that is used in retaining walls, bridge abutments, dams, seawalls, and dikes. Reinforcing elements used in MSE constructs can vary but commonly include metallic reinforcement elements such as steel strips or grids and geosynthetics such as polymeric strips.

MSE wall systems are used to construct embankments that are retained in part by precast wall panels. MSE wall systems consist of the original site ground, a concrete leveling pad, wall facing panels, coping, soil reinforcement, select backfill, and any loads or surcharges.

MSE walls are used to stabilize unstable slopes and retain the soil on steep slopes and under crest loads. The wall face is often of precast, segmental blocks, panels or geocells that can tolerate some differential movement. The walls are infilled with granular soil, with or without reinforcement, while retaining the backfill soil. Reinforced walls utilize horizontal layers typically of geogrids. The reinforced soil mass, along with the facing, forms the wall. In some types of MSE wall systems, each vertical fascia row is inset, thereby providing individual cells that can be infilled with topsoil and planted with vegetation to create a green wall.

The main advantages of MSE wall systems compared to conventional reinforced concrete walls is their ease of installation and quick construction. They do not require formwork or curing and each layer is structurally sound as it is laid, reducing the need for support, scaffolding or cranes. MSE wall systems also do not require additional work on the facing.

Reinforcement placed in horizontal layers throughout the height of MSE wall systems provides the tensile strength to hold the soil together. The reinforcement materials of MSE wall systems can vary. Originally, long steel strips 50 to 120 mm (2 to 5 in) wide were used as reinforcement. These strips are sometimes ribbed, although not always, to provide added friction. Sometimes steel grids or meshes are also used as reinforcement. Several types of geosynthetics can be used including geogrids and geotextiles. The reinforcing geosynthetics can be made of high density polyethylene, polyester, and polypropylene. These materials may be ribbed and are available in various sizes and strengths.

The manner in which MSE wall systems are constructed can be found in “Mechanical Stabilized Earth Wall Inspector's Handbook,” Paul D. Passe, State of Florida, Department of Transportation (Sep. 14, 2000), the entire content of which is hereby incorporated by reference.

During the construction of MSE wall systems, workers installing progressive rows of wall panels are required to work at greater heights relative to the original ground level. As the working height increases the risk for workers falling increase as they set wall panels into position.

OSHA Standards for the Construction Industry regulate fall protection in construction workplaces under 29 CFR §1926.500-503 including the provision and use of fall protection systems, including guardrail systems.

Current practice when constructing MSE wall systems is to cobble together guardrails from wood and secure them to adjacent structures using wooden clamp elements. Such guardrail systems are time consuming to both fabricate and remove and may often fail to meet the load requirements of 29 CFR §1026.502. Further such guardrail systems are not adjustable or adaptable for reuse in positions that have different wall and/or work surface elevations.

The present invention provides MSE wall guardrail systems that meet current safety requirements and can be installed and removed easily and quickly and are readily adaptable for different working and wall elevations.

BRIEF SUMMARY

According to various features, characteristics and embodiments of the present invention which will become apparent as the description thereof proceeds, the present invention provides a guardrail support bracket for use when constructing MSE wall systems which comprises:

a clamping portion which in configured to straddle the opposite sides of a MSE wall panel and fasten thereon;

a vertical support post that coupled to the clamping portion so as to be selectively fixed to the clamping based with a major length of the vertical support post extending above the clamping base portion or below the clamping base portion as desired; and

at least one guardrail support coupled to the vertical support post.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be described with reference to the attached drawings which are given as non-limiting examples only, in which:

FIG. 1 is a perspective view of a guardrail support bracket according to one embodiment of the present invention.

FIG. 2 is an exploded view of the guardrail support bracket of FIG. 1.

FIG. 3 is a photograph that depicts how guardrail support brackets of the present invention are used when installing a MSE wall panel between two adjacent wall panels.

FIG. 4 is a photograph that depicts how guardrail support brackets of the present invention are used when installing a MSE wall panel between an adjacent full height wall panel and a top course of a shorter inclined wall panel.

FIG. 5 is an end view photograph of FIG. 4

DETAILED DESCRIPTION OF THE DRAWINGS AND THE PRESENTLY PREFERRED EMBODIMENTS

The present invention relates generally to guardrail systems for construction sites and more particularly to guardrail systems for use in the construction of mechanical stabilized earth (MSE) walls. The guardrail systems of the present invention comprise guardrail support brackets and elongated guardrail elements that are received in and held by the guardrail support brackets. The guardrail support brackets have clamping portions that are configured and designed to straddle the opposite sides of a wall panel and be clamped thereto. Vertical support posts are coupled to the clamping portions in such a manner that the vertical support posts can be adjustably vertically positioned with respect to the clamping portions. The vertical support posts support at least one and preferably two or more guardrail supports into which elongated guardrail elements can be received and supported.

The clamping portions of the guardrail support brackets comprise a pair of legs that extend downward from an upper crosspiece. The pair of legs are substantially parallel to one another and spaced apart by a distance that is larger than the thickness of a wall panel to which the guardrail support bracket is to be attached to. In further embodiments of the present invention the length of the crosspiece can be adjustable to accommodate wall panels having different thicknesses. The pair of legs includes a front leg and a rear leg. Here reference to “front” and “rear” is made with respect to a work area where workers stand and are located during construction of an MSE wall system. “Rear” refers to the area behind a MSE wall where the workers stand and are located during construction of an MSE wall system and “front” refers to the area on the opposite side of the MSE wall.

The rear legs of the clamping portions of the guardrail support brackets are hollow and configured to receive the vertical support posts therein. The front legs and the upper cross pieces of the clamping portions can be hollow or solid as desired. The rear legs of the clamping portions of the guardrail support brackets are provided with mechanical mechanisms that allow the clamping portions to be tightened against a wall panel. One embodiment of a mechanical mechanism that can be used (and illustrated in the attached drawings) is a threaded clamping plate assembly that includes a thread member that extends through an internally threaded bore or block that is fixed to a side of the rear legs of the clamping portions. The free or rear end of the threaded clamping plate assembly can be rotated so that the plate end engages and tightens against the rear side of a wall panel. The rear of the threaded clamping plate assembly could be provided with a hand grip or lever by which a worker can tighten and untighten the threaded member, or a configuration such as hexagon shape to which a tool such as a wrench can be engaged to tighten and untighten the threaded member. The clamping plate can have a padded, e.g. surface to allow for gripping engagement. The clamping plate can be coupled to the threaded member so as to rotate freely with respect to the thread member if desired. In other embodiments of the present invention the mechanical mechanism that allows the clamping portions to be tightened against a wall panel can be a spring loaded mechanism that presses against the rear face of the wall panel, a cam lever that can be rotated to press against the rear face of the wall panel or any suitable mechanical mechanism that allows to quick and easy attachment of the clamping portion of the guardrail brackets to wall panels. In further embodiments wedge bolts or wedge blocks can be used to secure the clamping portions to wall panels. The clamping plate can comprise a circular shaped structure or an engaging structure of any desired shape.

The rear leg of the clamping portions of the guardrail brackets are hollow and have open upper and lower ends and are configured to receive the vertical support posts there in in such a manner that the vertical support posts can slide freely through the rear legs of the clamping portions. The vertical support posts have guardrail supports coupled thereto and can be positioned in the rear legs of the clamping portions so that the guardrail supports can be positioned above or below the clamping portions. In one embodiment the rear legs of the clamping portions and the vertical support posts can be provided with equally spaced through holes though which pins, bolts, clips, etc. can be inserted to secure the position of the vertical supports in the rear legs of the clamping portions.

The guardrail supports can have U-shaped structures that are configured and sized to receive and support elongated guardrail members such as wooden 2×4's therein. The guardrail supports can be movably positioned along the vertical support posts at any height as desired. For example the U-shaped structures of the guardrail supports can coupled to tubular bases that slide over the vertical support posts and can be secured in desired positions by through holes and locking pins, bolts, clips, etc. One, two or more guardrail supports can be provided on each vertical support post to provide adequate safety. In further embodiments that U-shaped structures can be provided with clamps, pins, etc. to secure the elongated guardrail elements therein. Otherwise the U-shaped structures could be hollow, square or rectangular structures could be used into which corresponding elongated guardrail elements could be inserted and secured. In further embodiments the U-shaped or hollow, square or rectangular structures are provided on horizontal support arms that can be adjusted lengthwise to provide clearance for MSE wall brackets that typically range from 3.5 to 5.25 inches.

The elements of the guardrail support brackets of the present invention can be made of any suitable metal. The elongated guardrail elements can be made of wood or metal. The tubular elements depicted in the attached figures that are shown to have square cross-sectional shapes can have circular cross-sectional shape or otherwise can have L- or Π-cross-sectional shapes or be or any suitable configuration

When used to install a MSE wall panel between two adjacent wall panels a pair of the guardrail support brackets of the present invention are used with one being attached near the end of each adjacent wall panel (See FIG. 3). The vertical support posts are positioned in the rear legs of the clamping portions so that the guardrail supports are vertically positioned to support elongate guardrail elements across the gap between the adjacent wall panels where the uninstalled wall panel is to be installed. The number and vertical heights of the elongated guardrails are to be sufficient to meet and provide adequate fall safety for workers.

When used to install a MSE wall panel between an adjacent full height wall panel and an top course of a shorter inclined wall panel a pair of the guardrail support brackets of the present invention are used with one being attached near the end of each adjacent wall panel. On the adjacent full height wall panel the vertical support post is positioned lower in the rear leg of the clamping portions and on the adjacent shorter inclined wall panel the vertical support post is positioned higher in the rear leg of the clamping portion (See FIGS. 4 and 5). In this way the guardrail supports can be position relatively horizontally across the gap even though the heights of the adjacent wall panels to which the guardrail brackets are attached are not the same heights. The number and vertical heights of the elongated guardrails are to be sufficient to meet and provide adequate fall safety for workers.

FIG. 1 is a perspective view of a guardrail support bracket according to one embodiment of the present invention. In FIG. 1 the clamping portion 1 is depicted as being attached to an end of a wall panel 2 (drawn in broken lines). The clamping portion 1 includes a crosspiece 3 and front and rear legs 4 and 5, extending downward from opposite ends of the crosspiece 3 in parallel to one another.

A threaded clamping plate assembly 6 is coupled to the rear leg 5 of the clamping portion 1 and includes a threaded member 7 and a plate structure 8 coupled to the distal end of the threaded member 7. The threaded member passes through an internal threaded bore in block 9 which is attached to rear leg 5 of the clamping portion. Alternative mechanical mechanisms to the threaded clamping plate assembly 6 that can be used are discussed above.

As depicted in FIG. 1 the vertical support post 10 is received in rear leg 5 of the clamping portion 1 which rear leg 5 is hollow and has opened top and bottom ends. The vertical support post 10 can slide freely through rear leg 5 so as to position a major portion of length of the vertical support post 10 above or below the clamping portion 1.

The vertical support post 10 and rear leg 5 of clamping portion 1 each are provided with a plurality of spaced apart through holes 11, 11′. These spaced apart through holes 11, 11′ can be aligned between the rear leg 5 and vertical support post 10 so that one or more pins 12 can be inserted through the aligned through holes 11, 11′ to adjust and secure the position of the vertical support post relative to the clamping portion.

In FIG. 1 two guardrail supports 13 are coupled to the vertical support post 10. The guardrail supports include U-shaped structures 14 that are configured to receive and support elongated guardrail elements 15 therein (drawn in broken lines). The U-shaped structures 14 in FIG. 1 are provided on horizontal support arms 16 that extend out from tubular base members 17 that can be slide along the vertical support post 10 and locked in position by aligning through holes 18 and 11 and inserting pins 19 through the aligned through holes 18 and 11.

FIG. 2 is an exploded view of the guardrail support bracket of FIG. 1 which depicts the separate elements that make up a guardrail support bracket according to one embodiment of the present invention.

Although the present invention has been described with reference to particular means, materials and embodiments, from the foregoing description, one skilled in the art can easily ascertain the essential characteristics of the present invention and various changes and modifications can be made to adapt the various uses and characteristics without departing from the spirit and scope of the present invention as described above and set forth in the attached claims.

Claims

1. A guardrail support bracket for use when constructing MSE wall systems which comprises:

a clamping portion which in configured to straddle the opposite sides of a MSE wall panel and fasten thereon;

a vertical support post that coupled to the clamping portion so as to be selectively fixed to the clamping based with a major length of the vertical support post extending above the clamping base portion or below the clamping base portion as desired; and

at least one guardrail support coupled to the vertical support post.

2. A guardrail support bracket according to claim 1, wherein the clamping portion comprises a crosspiece and two legs which extend in parallel to each other from opposite ends of the crosspiece.

3. A guardrail support bracket according to claim 2, wherein one of legs of the clamping portion is a hollow leg and the vertical support post extends through the hollow leg.

4. A guardrail support bracket according to claim 2, wherein the vertical support post and hollow leg of the clamping portion each comprise spaced apart through holes that can be aligned so as to receive a pin to adjust the position of the vertical support post relative to the clamping portion.

5. A guardrail support bracket according to claim 2, wherein one of the two legs of the clamping portion includes a retractable structure that can be activated to engage a MSE wall panel so as to fasten the clamping portion onto the wall panel.

6. A guardrail support bracket according to claim 5, wherein the retractable structure is a plate.

7. A guardrail support bracket according to claim 6, wherein the plate is coupled to one of a threaded member, spring clamp or cam.

8. A guardrail support bracket according to claim 6, wherein the plate has a circular shape.

9. A guardrail support bracket according to claim 1, wherein the at least one guardrail support is configured to receive and support an elongated guardrail member.

10. A guardrail support bracket according to claim 9, wherein the at least one guardrail support is adjustably coupled to the vertical support post.

11. A guardrail support bracket according to claim 10, wherein the at least one guardrail support extends outward from the vertical support post.

12. A guardrail support bracket according to claim 11, wherein the distance the guardrail support extends outward from the vertical support post is adjustable.