US20100272509A1

US20100272509A1 - Traffic barrier section

Info

Publication number: US20100272509A1
Application number: US12/430,738
Authority: US
Inventors: Greg Ritke
Original assignee: TRI STATE CONSTRUCTION Inc
Current assignee: Tri-State Construction Inc; TRI STATE CONSTRUCTION Inc
Priority date: 2009-04-27
Filing date: 2009-04-27
Publication date: 2010-10-28

Abstract

A traffic barrier section is disclosed herein. The traffic barrier section includes a prefabricated or pre-cast concrete barrier wall section and a poured in-place (i.e., in-situ) moment slab footing. As constructed, the traffic barrier section is suitable for constructing a continuous protective barrier for a roadway. In that regard, a plurality of traffic barrier sections are placed side-by-side in close proximity and supported on a retaining wall to form a continuous protective barrier along the edge of the roadway. In use, the erected continuous protective barrier restrains a moving vehicle on the elevated roadway from traveling over the edge of the retaining wall.

Description

BACKGROUND

Traffic barriers have been utilized for many years on roads to keep a moving vehicle from crossing into the path of oncoming traffic or from driving off the roadway. Traffic barriers can be especially useful on elevated or split-level roadways, such as bridges, entrance ramps, or access roads to highways, to prevent a vehicle from driving off the roadway onto a lower level roadway or the like. Often times, these elevated roadways are formed by either cutting through a hill or by piling earthen material (e.g., soil, clay, rock, sediment, etc.) with or without reinforcements to form a laterally stabilized composite earth structure to support the roadway.
Either method of construction may result in a wall face that needs to be supported by a retaining wall. If this retaining wall is close to the road surface there is a need for a traffic barrier disposed on top of the retaining wall and anchored in place by what is called a moment slab in the construction industry. Together, the traffic barrier and the moment slab form a traffic barrier system, sometimes referred as a “moment slab barrier.”
Current construction methods of traffic barrier systems such as the one described above are cast-in-place. However, this construction method requires forms to be constructed by workmen on scaffolding. Hand construction of the forms and pouring of concrete in place is slow and labor intensive. Also important are the time and space constraints imposed on such construction projects, particularly in urban environments, where time is of the essence to minimize traffic disruptions.
Therefore, a need exists for a traffic barrier and/or methods of installation that can provide the desired protection barrier in a more cost, time and labor efficient manner.

SUMMARY

This summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This summary is not intended to identify key features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter.
In accordance with aspects of the present invention, a pre-cast traffic barrier wall for use in constructing a moment slab barrier is provided. The traffic barrier wall section includes a wall body having a front surface, a back surface, a top surface, a bottom surface, and first and second side surfaces. The back surface comprises an inclined upper back surface section and a lower back surface section. The traffic barrier wall section further includes a plurality of reinforcement members extending from the lower back surface section.
In accordance with another aspect of the present invention, a method is provided for constructing a moment slab barrier wall section at a site. The method includes obtaining a pre-cast retaining wall section. The pre-cast wall section includes a wall body having a front surface, a back surface, a top surface, a bottom surface, and first and second side surfaces. The back surface comprises an inclined upper back surface section and a lower back surface section. The traffic barrier wall section further includes a plurality of reinforcement members extending from the lower back surface section. The method also includes placing the pre-cast retaining wall onto a support surface in an upright orientation and making a moment slab footing in proximity to the lower back surface section of the retaining wall section that is mechanically coupled to the retaining wall section.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing aspects and many of the attendant advantages of this invention will become more readily appreciated by reference to the following detailed description, when taken in conjunction with the accompanying drawings, wherein:

FIG. 1 is a perspective, environmental view of a continuous protective barrier erected with a plurality of representative moment slab barrier sections formed in accordance with aspects of the present invention;

FIG. 2 is a magnified, cross-sectional view of the erected moment slab barrier of FIG. 1;

FIG. 3 is a perspective view of one embodiment of a barrier wall section suitable for use in the moment slab barrier sections of FIGS. 1 and 2;

FIG. 4 is a cross-sectional view of the barrier wall section of FIG. 3;

FIG. 5 is a cross-sectional view of another representative embodiment of a barrier wall section formed in accordance with aspects of the present invention;

FIGS. 6-12 are sequential environmental and cross-sectional views of the moment slab barrier sections being constructed in accordance with aspects of the present invention;

FIG. 13 is a magnified, cross-sectional view showing another embodiment of a moment slab barrier section installed in a single slope application.

DETAILED DESCRIPTION

Embodiments of the present invention will now be described with reference to the accompanying drawings where like numerals correspond to like elements. Embodiments of the present invention are directed to pre-cast concrete moment slab barrier sections and methods of constructing the same. One illustrative embodiment of a moment slab barrier section, generally designated 20, suitable for use in constructing a continuous protective barrier for a roadway 22 is shown in the environmental perspective view of FIG. 1. As constructed, the roadway 22 is supported by stabilized earth 24, and a plurality of moment slab barrier sections 20 are erected side-by-side in close proximity and supported on a retaining wall 26 to form a continuous protective barrier along the edge of the roadway 22. In use, the erected continuous protective barrier restrains a moving vehicle on the elevated roadway 22 from traveling over the edge of the retaining wall 26.
Referring now to FIGS. 1-4, the moment slab barrier section 20 will be described in more detail. As best shown in FIGS. 2-4, the moment slab barrier section 20 includes a prefabricated or pre-cast concrete barrier wall section 30 (hereinafter “the barrier wall section 30”) and a poured in-place (i.e., in-situ) moment slab footing 32. The barrier wall section 30 comprises a concrete or similarly constructed unitary wall body 36 that defines a front surface 40, a back surface 42, a top surface 46, a bottom surface 50, a left side 54, and a right side 58. For description purposes only, the front surface 40 of the barrier wall section 30 is generally the side that will be seen facing away from the roadway after the protective barrier is complete. The front surface 40 may be finished in an architecturally pleasing manner, if desired.
The back surface 42 of the barrier wall section 30 typically faces the roadway 22. In the embodiment shown in FIGS. 2-4, the back surface 42 includes a generally inclined or slanted upper surface section 42 a and a substantially vertical lower surface section 42 a. Thus, the barrier wall section 30 may be constructed to be wider from the front surface 40 to back surface 42 at the lower portion thereof (i.e., towards the bottom surface 50) as compared to the upper portion proximate the top surface 46. In another embodiment of a moment slab barrier section 130, best shown in FIG. 5, the back surface 142 is configured so as to create a conventional New Jersey profile (or “Jersey” profile) for deflecting or redirecting a moving vehicle back towards the roadway surface 22. The New Jersey profile includes an upper inclined surface 142 a extending from the top surface 146 and sloping downwardly at a first acute angle with respect to a vertical plane. An intermediate inclined surface 142 b extends from the upper inclined surface 142 a and slopes downwardly at a second acute angle which is greater than the first angle. A substantially vertical lower surface section 142 c extends between the intermediate inclined surface section 142 b and the bottom surface 150.
Returning to FIGS. 2-4, opposite the back surface 42 a is the front surface 40, and as stated above, can provide an ornamental aspect to the traffic barrier. In the embodiment shown, the front surface 42 extends somewhat vertically from the top surface 46 to the bottom surface 50. The bottom surface 50 may have any suitable configuration for its attended application. Generally, the bottom surface 50 serves as the support interface of the barrier wall section 30 with the earth 24, and in one embodiment, extends generally horizontally between the front surface 40 and the back surface section 42 b. In the embodiment shown in FIG. 3, the bottom surface 50 is defined by adjacent stepped surface sections 50 a and 50 b, thereby forming a shoulder 60. The shoulder 60 is formed in the bottom surface 50 of the barrier wall section 24 for interfacing with the retaining wall 26, as best shown in FIGS. 2 and 4. Alternatively, the bottom surface 50 may be one planar surface that is disposed substantially horizontally with respect to the vertical front surface 46, for use in such applications as, for example, the single slope of FIG. 13.
As constructed, the barrier wall section 30 may further include at least one, and preferably, a plurality of steel reinforcement members 66, known in the industry as “rebar,” to resist directly applied stresses to the pre-cast concrete wall section. The reinforcement members 66 may be laterally and/or longitudinally disposed or embedded throughout the barrier wall section 30, or may be disposed in any orientation, depending on the final shape of the barrier wall section 30 and the application of the barrier wall section 20. Alternatively, the reinforcement members 66 may be in the form of reinforcement wire mesh embedded throughout the barrier wall section 30.
In the embodiment shown in FIGS. 2-3, the barrier wall section 30 includes first, second, and third sets 66 a, 66 b, and 66 c of reinforcing members. The first set of reinforcement members 66 a extend outwardly from the surface section 42 b of the barrier wall section 24. As best shown in FIGS. 2-4, each reinforcement member 66 a is generally U shaped and oriented as best shown in FIG. 4. The second set of reinforcement members 66 b are spaced apart and oriented so as to form the general side profile of the barrier wall section 30, as best shown in FIG. 4. The third set of reinforcement members 66 c are disposed generally horizontally along the length of the barrier wall section 30 and across the reinforcement members 66 a and 66 b. If desired, one or more of the reinforcement members 66 may be tied or mechanically connected together. It will be appreciated that the barrier wall section 30 may be formed with other features, as such as junction boxes, drains, etc.
One representative method for installing the moment slab barrier section 20 in accordance with aspects of the present invention will now be described in detail with reference to FIGS. 6-12. The following will describe one or more moment slab barrier sections 20 being added to a continuous protective barrier section. As shown in FIG. 6, the first step in order to install a moment slab barrier section 20 to a continuous protective barrier section is to prepare the general area 100 surrounding the resting position of the moment slab barrier section 20. For example, the site may need to be excavated, thereby removing or relocating earthen material. Alternatively, additionally earthen material (e.g., rock, soil, etc.) may be added to build a suitable foundation on which the moment slab barrier section 20 will rest.
In the embodiment of FIG. 6-8, a footing bed or foundation 110 may be constructed. The bed or foundation 110 is suitably dimensioned for the size of the footing 32 (see FIG. 1) to be poured. The top surface 114 (FIG. 8) of the bed or foundation 110 may be compacted in such a way that the weight of the barrier wall section 30 and/or footing 32 will not settle or sink over time. The bed or foundation 110 may include crushed aggregate or other subgrade preparation (not shown), if needed. It will be appreciated that the bottom surface 114 of the bed 110 may require additional preparation. For example, the bed may need to be surveyed after compaction to ensure the moment slab barrier section 20 will be aligned properly upon completion.
Next, one or more barrier wall sections, such as barrier wall sections 30, are sequentially picked up with a crane or other lifting apparatus (not shown) and placed into the appropriate position with respect to the bed 110. In the embodiment shown in FIGS. 7 and 8, the barrier wall section 30 is placed on top of the retaining wall panel 26, with the shoulder 60 adjacent the road side corner of the retaining wall panel 26. In this position, a portion of the barrier wall section 30 hangs over the edge of the retaining wall panel 26, while the opposite portion is supported by the bed 110, as best shown in FIGS. 2 and 8. Once the barrier wall section 30 has been set in placed, the alignment of the barrier wall section 30 can be checked and adjusted, if desired.
For example, it may be preferable that the barrier wall sections 30 of the continuous protective barrier are accurately aligned both vertically and horizontally in order to maintain a high standard of architectural finish. Height adjustments can be made by placing shims or other similar structures known in the art, under the bottom surface 50 to lift either the left side 54 and/or the right side 58. In order to place these shims in place, a jack or other common lifting apparatus (not shown) can be placed under the bottom surface 50 of the barrier wall section 30. Alternatively, hooks (not shown) may be cast into the barrier wall sections 30 or holes may be formed in the barrier wall section 30 to receive a corresponding lifting device for adjusting the position of the barrier wall section 30. The shims could also be placed during the initial setting of the barrier wall section 30. Once there is sufficient gap under the bottom surface 50 upon lifting, shims or like structures can be placed until the desired wall section position is achieved.
The barrier wall section 30 may then be optionally secured temporarily in its desired position prior to forming the moment slab footing 32. In order to temporarily secure the wall section 30 before the footing 32 is formed, temporary braces (not shown) or other support structure may be used. The number of braces may depend on the size and shape of the wall, or the size, shape, and material of the braces.
Once the barrier wall section 30 is in place and optionally supported with the temporary braces, the moment slab footing 28 of sufficient size can then be prepared. It will be appropriated that the size of the moment slab footing 32 is typically designed based on the size and shape of barrier wall section 30. The moment slab footing 32 is prepared by first constructing a footing form 170 of a sufficient size at the base of the barrier wall section 30. For example, the ratio of the width W of the moment slab footing 32 to height H of the barrier wall section 30 (see FIG. 2) may be in the range of 0.6 to 2.0.
Next, a plurality of reinforcement members 172 and 174 may be disposed within the inner cavity created by the form 170, as best shown in FIG. 9. In one embodiment, the reinforcement members 172 are placed in general alignment with the reinforcement members 66 a, as shown in FIGS. 2 and 9, and reinforcement members 174 are placed across the reinforced members 66 a and 172 (i.e., along the length of the barrier wall section). The reinforcement members 172 and 174 of the footing 32 can then be tied or mechanically connected to the reinforcement members 66 a of the barrier wall section 30 if desired, so that the footing 32 becomes an integral part of the barrier wall section 30 once the poured concrete has cured.
Continuing to FIG. 10, concrete is then poured into the form 170 and finished, as known in the art. After the concrete moment slab footing 32 has cured, the optional temporary braces (not shown) and related components can be removed, if used. Once all of the optional temporary braces have been removed, soil or earth can then be “backfilled” or placed into the area 180 (FIG. 11) to a suitable level. The road may then be finished, including forming an optional road fill layer 190 and the roadway 22 on top of the footing 32, as best shown in FIG. 2. These steps may then be repeated until the desired length of the protective barrier is completed for the roadway 22. It will be appreciated that the order of the steps described herein may be altered, some steps may be combined or removed, and other steps added.
Once completed, vehicles may traverse the roadway 22. When a vehicle driving along the roadway 22 strikes the moment slab barrier section 20, the profiled back surface 42 will direct the vehicle's wheel upward so as to prevent damage to the vehicle's body. This will also slow the movement of a vehicle down so that the driver will be able to regain control of his vehicle and steer it back onto the roadway 22. The force applied by the vehicle's impact that would otherwise tend to tip the moment slab barrier section 20 over the retaining wall 26, but this tipping force is overcome by the integrated and in-situ formed moment slab footing 32, and well as the roadway 22 above the moment slab footing 32 and any road fill layer 190 (e.g., crushed rock layer, etc.) disposed in-between the moment slab footing 32 and the roadway 22.
While exemplary embodiments of the invention have been illustrated and described, it will be appreciated that various changes can be made therein without departing from the spirit and scope of the invention.

Claims

1. A pre-cast traffic barrier wall, comprising:

a wall body having a front surface, a back surface, a top surface, a bottom surface, and first and second side surfaces, wherein the back surface comprises an inclined upper back surface section and a lower back surface section; and

a plurality of reinforcement members extending from the lower back surface section.

2. The pre-cast retaining wall of claim 1, wherein the at least one of the plurality of reinforcement members extends through a portion of the wall body.

3. The pre-cast retaining wall of claim 1, wherein the plurality of reinforcement members extend orthogonally from the lower back surface section in a spaced apart manner.

4. The pre-cast retaining wall of claim 3, wherein the plurality of reinforcement members are a plurality of U-shaped reinforcement members disposed in a spaced apart manner, the U-shaped reinforcement members defining first and second legs that extend from the lower back surface section and a cross member that is embedded in the wall body.

5. The pre-cast retaining wall of claim 1, further including longitudinally and/or laterally extending reinforcement members embedded in wall body.

6. The pre-cast retaining wall of claim 1, wherein the back surface has a Jersey profile.

7. The pre-cast retaining wall of claim 1, wherein the bottom surface includes a stepped section for interfacing with a top of a retaining wall.

8. A method of constructing a moment slab barrier wall section at a site, comprising:

obtaining a pre-cast retaining wall section, the pre-cast wall section having a wall body that includes a front surface, a back surface, a top surface, a bottom surface, and first and second side surfaces, wherein the back surface comprises an inclined upper back surface section and a lower back surface section, and a plurality of reinforcement members extending from the lower back surface section;

placing the pre-cast retaining wall onto a support surface in an upright orientation; and

making a moment slab footing in proximity to the lower back surface section of the retaining wall section that is mechanically coupled to the retaining wall section.

9. The method of claim 8, wherein the pre-cast retaining wall section is formed at a location different from the site.

10. The method of claim 8, further comprising temporarily restraining the retaining wall section in its upright position prior to making the footing.

11. The method of claim 8, further comprising adjusting the height of the retaining wall section prior to making the footing.

12. The method of claim 8, wherein making the footing around the base of the wall further comprises

erecting a footing form in proximity to the lower back surface section of the retaining wall section, the form creating a cavity for receiving concrete poured therein; and

pouring concrete into the cavity of the footing form.

13. The method of claim 12, wherein making the footing further includes installing at least one reinforcement member in the cavity of the footing form prior to pouring the concrete.

14. The method of claim 13, wherein making the footing further includes mechanically connecting the footing reinforcement member with at least one of the plurality of retaining wall section reinforcement members prior to pouring the concrete.

15. The method of claim 8, further comprising

preparing a supporting surface of a size that is larger than the bottom surface of the retaining wall section.

16. The method of claim 8, wherein placing the pre-cast retaining wall onto a support surface in an upright orientation including placing a portion of the pre-cast wall section onto a top of a retaining wall.

17. The method of claim 16, wherein the bottom surface includes a stepped section for interfacing with the top of a retaining wall.