BLAST PROTECTION SYSTEM

Abstract

A blast protection barrier system to protect structures from blast shock waves initiated by detonation of a large bomb at ground level adjacent the structure, and in particular a bomb transported by a land vehicle, having an outer perimeter wall retaining a large quantity of loose particulate matter, the wall having multiple horizontally extending folds, each fold having an outwardly facing inclined, preferably concave, segment joined to a generally horizontal segment, such that the blast shock wave causes the wall to extend or expand in a generally vertical direction to dissipate and divert the destructive energy of the bomb and minimize damage to the structure.

Description

BACKGROUND OF THE INVENTION

The invention relates most generally to devices, structures, apparatuses and systems designed to protect structures from explosive blast effects, and more particularly to such devices, etc., that are designed to protect against explosions from large bombs detonated adjacent the structure being protected. Even more particularly, the invention relates to such devices, etc., that incorporate protective barriers erected externally to or adjacent the structure being protected.

An increasingly common terrorist tactic is the detonation of large portable bombs, usually transported within a car or truck, to destroy or severely damage large buildings or similar fixed structures. Delivering the bombs to the target can be relatively easy, as the transport vehicle is simply driven to a location adjacent the building and the explosives are detonated. Many important buildings are now protected by exclusionary barriers that prevent a vehicle from being brought near the building, but it is not possible to protect all vulnerable structures in this manner due to economic and physical space considerations, as most buildings front on a public street open to all vehicular traffic. In such a circumstance, providing an exclusionary safety buffer of sufficient area may be possible only by closing the street—an impractical solution. In addition, buildings previously considered to be outside the list of potential targets may become targets if temporarily occupied by targeted personnel, such as is the case for example of buildings now occupied in Iraq by U.S. personnel. Furthermore, structures other than buildings may be possible targets, such as for example bridge support towers, especially on suspension bridges, television towers, gas storage tanks, etc. Bridges columns are especially vulnerable as the columns are always positioned adjacent the roadway, and the columns are the sole supports for the roadway. Destruction of bridges disrupts vehicular travel and may simultaneously block waterways or ports.

Detonation of an explosive produces a shock wave of dramatically increased pressure and thermal energy, which if unmitigated is often sufficient to cause massive destruction of fixed structures within effective range of the explosion. If directed at a vulnerable area of a tall or large structure, such as a high-rise tower or a suspension bridge, the direct blast damage may instigate indirect structural failure of a magnitude sufficient to destroy the entire structure through collapse. One approach to protect structures from attack involves the use of mechanical or physical barrier structures to absorb, deflect or otherwise mitigate the blast effects. These barriers are wall-like structures that are constructed to absorb the blast shock wave, to divert or vent the shock wave away from the structure, or a combination of both. A simple form of blast protection barrier is a large earthen berm or a thick concrete wall that is erected a short distance from the structure being protected. Another type of blast protection barrier is represented by shock wave absorbing pads or curtains that are mounted on the exterior walls of the structure. A third type of blast protection device involves blanket or containers built to suppress an explosion occurring beneath the blanket or within the container.

U.S. Pat. No. 4,433,522, issued to Yerushalmi on Feb. 28, 1984, describes a protective barrier of the first type. The barrier is a protective wall structure having two spaced groups of sheet metal panels connected in interlocking manner to define two opposing faces and a large number of diagonally positioned panels extending between the two faces in a saw tooth orientation. The vertical channels formed by the diagonal panels are filled with concrete or asphalt. Another example of a wall barrier is shown in U.S. Pat. No. 5,225,622, issued to Gettle et al. on Jul. 6, 1993, which shows a specialized assembly of porous screens containing shock wave attenuating material having fluid characteristics. An example of the second type of blast protection device is shown in U.S. Pat. No. 5,576,511, issued to Alhamad on Nov. 19, 1996. The Alhamad device is a pad composed of multiple sheets of expanded metal net separated by core layers of porous material comprising fiberglass, cotton batting or small balls of expanded metal net. The third type of device, the blast suppressing blanket or container, is illustrated in U.S. Pat. No. 3,801,416, issued to Gulbierz on Apr. 2, 1974, U.S. Pat. No. 4,149,649, issued to Szego on Apr. 17, 1979, and U.S. Pat. No. 4,727,789, issued to Katsanis et al. Mar. 1, 1998.

It is an object of this invention to provide a blast protection system of the barrier or shield type, wherein the barrier can be constructed or assembled about the perimeter of a structure to be protected, with the barrier mitigating the shock wave of an explosive detonated near or adjacent the barrier such that the structure is minimally or not damaged. It is a further object to provide such a blast protection system where the blast force is absorbed and diverted from the structure being protected. It is a further object to provide such a blast protection system that is relatively economical in material and installation costs, can be installed quickly, and is simple to construct. Additional intended objects of the invention will be discemable from the disclosure to follow.

SUMMARY OF THE INVENTION

The invention is a blast protection system to protect buildings, bridge columns and other fixed structures from shock wave effects of explosives detonated adjacent the structures, and in particular to protect structures susceptible to attack by large amounts of explosives transported in vehicles, commonly referred to as a car bomb or truck bomb. The invention is designed to absorb and divert the blast energy in order to minimize damage to the structure, and is particularly adapted to be used in circumstances where positioning of the explosive adjacent the structure is relatively easy, due to the fact that the structure lies adjacent a public roadway. The invention is composed of material that is relatively low cost, and installation of the invention is also at relatively low cost.

The blast protection barrier system comprises in general a wall composed of a sheet metal, preferably steel plate, that is arranged as a perimeter to retain a large amount of loose particulate matter. The wall is formed with multiple horizontal folds of particular configuration such that the blast shock wave from a bomb explosion causes the wall to unfold or expand in a generally vertical or upward direction, rather than collapsing generally horizontally inward or downward. Each fold configuration comprises a generally horizontal flat segment and an outwardly facing inclined segment, most preferably a concave or radiused segment, with the lower end of the inclined segment joined to the rear edge of the horizontal segment along an interior junction and with the upper end of the inclined segment joined to the forward edge of the horizontal segment along an exterior fold or junction. This pattern is repeated vertically to obtain a desired height for the wall. A footing member or base extends to the rear of the wall.

The particulate matter comprises a large amount of relative small and relatively lightweight particles that absorb and dissipate the energy from the blast shock wave, and preferably consists of sand or similar inorganic or inert matter. The particulate matter may be an aggregate or mixture of particles of differing physical properties, such as for example sand, rubber, plastic beads or the like.

The blast protection system is positioned so as to abut or reside a short distance from the structure to be protected. The wall members are joined by welding, mechanical fasteners or similar means to create an extended or multi-directional perimeter, and are preferably secured to the ground surface by connecting mechanical fasteners to the footing members. The particulate matter is placed within the interior of the perimeter formed by the wall members. In the event that an explosive is detonated in close proximity to the blast protection system, the blast shock wave causes the folds of the wall to unfold and extend in an upward direction, thereby initiating a diversion of the blast energy away from the structure being protected. This upward motion is likewise transferred to at least a portion of the particulate matter, such that the horizontal energy of the blast is dissipated through absorption by the loose particles and diverted into a generally vertical direction by upward expulsion of the particles as well, thereby minimizing the amount of energy that impacts the structure directly.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a top plan view of the invention as positioned to protect a bridge column.

FIG. 2 is a front view of the invention of FIG. 1.

FIG. 3 is a partial cross-sectional view of the invention taken on line III-III of FIG. 1.

FIG. 4 is an illustration showing the reaction of the folds in the wall portion of the invention in response to the horizontal shock wave of an explosion.

FIG. 5 is a top view of an alternative embodiment of the invention showing the use of multiple folded walls arranged in a staggered fashion.

FIG. 6 is a partial cross-sectional view of an alternative configuration for the folds in the wall of the invention.

FIG. 7 is a partial cross-sectional view of an alternative configuration for the folds in the wall of the invention.

FIG. 8 is a partial cross-sectional view of an alternative configuration for the folds in the wall of the invention.

DETAILED DESCRIPTION OF THE INVENTION

With reference to the drawings, the invention will now be described in detail with regard for the best mode and the preferred embodiment. In general, the invention is a blast protection barrier system 10 comprising horizontally folded wall members 20 and energy dissipating particulate matter 30 used to protect a structure 99 from a blast shock wave resulting from detonation of an explosive adjacent the blast protection system 10. The system 10 will typically comprise multiple linear wall members 20 joined as required to shield the structure 99 from multiple directions by forming a perimeter. The protected structures 99 may consist of buildings, towers, storage tanks, or any other structure or object requiring protection of the type described herein. For purposes of illustration, the invention is herein shown as protecting the three sides of a bridge column facing a roadway, but it is to be understood that the invention may be constructed to face any number of directions and may be constructed to completely encircle a structure 99 if required.

Referring now to FIGS. 1 and 2, the blast protection system 10 comprises at least one wall member 20 and a relatively large amount of particulate matter 30 disposed directly behind and abutting the walls 20. The walls 20 are preferably connected to each other in known modular manner by welding, mechanical fasteners or the like to form a perimeter to contain the particulate matter 30. The walls 20 are the outer barrier members that receive the initial blast shock wave from a detonated explosive or bomb, and thus are assembled to present a continuous front in each direction from which an explosive blast may occur. As shown in these figures, the structure 99 being protected is a bridge support column that faces a roadway on three sides with the fourth side facing away from the roadway over the water. In this situation, only the three sides facing the roadway need protection. The particulate matter 30 is disposed between the wall members 10 and the protected structure 99 with its top surface exposed or, if covered in any manner for protection from the environment, covered only with a lightweight tarp, fabric or similar material such that upward movement of the particulate matter 30 is minimally impeded. As shown in FIG. 1, the particulate matter abuts the structure 99, but alternatively as shown in FIG. 5 a space may be included between the blast protection system 10 and the structure 99.

The particulate matter 10 comprises generally small particles of inorganic and inert matter, and preferably comprises sand or a mixture of sand and other particles, such as plastic beads, rubber particles or similar articles. The particulate matter 10 is a loose distribution of particles, which serve to absorb and dissipate some of the horizontal energy of a blast shock wave. The size and weight of the individual particles of the particulate matter 10 may vary, but should be kept sufficiently small such that the particulate matter 10 does not itself become damaging projectiles when ejected upward. A sufficient quantity of particulate matter 10 is provided so that the surface of the particulate matter 10 is generally level with the top of the walls 20. Preferably, the particulate matter should extend at least approximately five feet behind the wall 20.

The walls 20 are composed of a sheet metal material of relatively high strength, such as preferably steel plate. A preferable thickness for the wall 10 when composed of steel plate is from about ⅜ to ⅝ inches, which is sufficient to insure that the steel plate is deformed in response to a blast shock wave but is not destroyed so as to result in projectiles or shrapnel. The wall 20 is formed with multiple horizontal folds 40 manufactured from a single plate, as shown in FIG. 3. Each fold 40 comprises an outwardly facing inclined segment 21, most preferably a concave segment as shown in the figure, a horizontal segment 22, an exterior fold 23 and an interior junction 24. The concave inclined segment 21 as shown is a curved portion that is concave to the exterior of the wall 20, and is preferably configured as an arc segment of a circle. The horizontal segment 22 is a longitudinally extending, generally horizontally disposed, general flat or planar segment of the wall 20. The longitudinal junction of the upper edge of the concave segment 21 and the forward edge of the horizontal segment 22 defines an exterior fold 23, which most preferably comprises a full 180 bend of the material in order to provide a well-defined exterior fold 23. Such a fully folded configuration increases the beam-like strengthening effects of the exterior fold relative to forces encountered in the horizontal direction. The longitudinal junction of the lower edge of the concave inclined segment 21 and the rear edge of a different horizontal segment 22 defines an interior junction 24, preferably at an angle of 90 degrees. This pattern is repeated in the vertical direction until the desired height for wall 20 is attained. The upper edge of the wall 20 is formed by the upper edge of the uppermost concave inclined segment 21. The longitudinal lower edge of the wall 20 is bent inwardly to define a footing or base member 26 that extends inwardly from wall 20. This footing member 26 may be formed as a flange member only several inches in depth, or may be extended to form a full bottom for the blast protection system 10. Preferably, the footing member 26 is secured to the ground surface 98 by mechanical fasteners or like means.

The height and length of the wall 20 may vary as needed. Representative dimensions for the configuration of the folds 40 comprise concave inclined segments 21 having a curve with a centered radius of one foot and horizontal segments approximately eight to twelve inches deep. The walls 20 will have a height sufficient to extend above most common trucks, and preferably extend at least fourteen feet in height. An alternative configuration for the folds 40 of wall 20 is shown in FIG. 6, where the lower edge of the concave inclined segment 21 transitions into a preferably vertical, generally planar extension segment 25, the lower edge of which is joined to the rear edge of a horizontal segment 22. Other configurations for folds 40 are also possible within the scope of the invention, provided that the configuration is such that shape of the folds 40 translates a horizontal blast shock wave into an upward direction, as shown in FIG. 4. For example, as shown in FIG. 7, the inclined segment 21 may be relatively planar rather than concave. A more preferred embodiment of the planar inclined segment 21 is shown in FIG. 8, wherein the exterior folds 23 are crimped to extend a short distance inward. This configuration increases the beam strengthening effects of the exterior folds 23.

As seen in FIG. 4, the longitudinally extensive exterior folds 23 create a multiple beam effect such that the wall 20 is highly resistant to inward flexing when exposed to the horizontal forces from the explosive shock wave direction 97. The energy impinging on wall 20 in the horizontal blast shock wave direction 97 thus passes the exterior folds 23 and is received by the concave inclined segments 21. The wall 20 expands or unfolds in a generally upward energy dissipation direction 96 because of the energy received by the folds 40, in particular because of the specialized configuration. The angle of the interior junctions 24 increases, the curvature of the concave inclined segments 21 is reduced or flattened, and the horizontal segments 22 are pulled into an inclined orientation. This upward expansion redirects the shock wave energy as it passes through the wall 20 and into the particulate matter 30, which absorbs some of the energy due to its loosely packed structure and where some of the particulate matter 30 is ejected upward in response to the upward expansion of the wall 20 and the fact that the top surface of the particulate matter 30 is uncovered and unrestricted. In this manner the destructive energy from the bomb detonation is dissipated and diverted away from the structure 99 being protected, thereby minimizing the damage to the structure 99.

As a contrasting example, walls composed of folded pleats having flat segments joined at angular junctions without horizontal segments or with inclined segments facing inward would not function in the manner of the invention, as the horizontal energy from the blast shock wave would cause the wall to collapse inwardly or downward, with no resulting diversion of energy from the horizontal to the vertical direction.

An alternative embodiment of the invention is shown in FIG. 5, where a series of walls 20 are incorporated into the blast protection system 10 in a staggered or generally concentric manner with multiple areas of particulate matter 30 between each of the series of walls 20. In the embodiment shown, there is a first set of connected exterior walls 20′, a second set of connected internal walls 20″ and a third set of rear walls 20′″. In this embodiment, any horizontal energy passing through the exterior walls 20′ and the outermost mass of particulate matter 30 encounters the second set of walls 20″, where the energy is again diverted through vertical expansion of the second walls 20″ and dispersion of the secondary mass of particulate matter 30 disposed behind the second set of walls 20″ in the same manner as before.

It is understood that equivalents and substitutions for certain elements set forth above may be obvious to those skilled in the art, and therefore the true scope and definition of the invention is to be as set forth in the following claims.

Claims

1. (canceled)

2. (canceled)

3. (canceled)

4. A blast protection system for protecting structures from damage from blast shock waves created by an explosion said system comprising:

at least one wall formed of a sheet metal and comprising multiple horizontal folds, said folds comprising a generally horizontal segment and an outwardly facing concave inclined segment, wherein the configuration of said folds is such that said wall expands in a generally upward direction when impacted by a horizontal blast shock wave; and

particulate matter disposed behind and abutting said wall, whereby said particulate matter absorbs and dissipates energy transferred through said wall;

wherein said concave inclined segments have a lower edge and an upper edge, and wherein said horizontal segments have a forward edge and a rear edge, and wherein said lower edge of said concave inclined segment is connected to said rear edge of said horizontal segment, and wherein said upper edge of said concave inclined segment is connected to said forward edge of said horizontal segment.

5. The system of claim 4, further comprising a footing member extending inwardly from said lower edge of the lowermost of said concave inclined segments.

6. The system of claim 4, wherein said folds further comprise a generally vertically disposed extension segment disposed between said horizontal segments and said concave inclined segments.

7. The system of claim 4, wherein said particulate matter is chosen from the group of particulate matter consisting of sand, rubber particles and plastic beads.

8. The system of claim 1, further comprising at least one second wall disposed internally to said at least one wall, wherein said particulate matter is disposed between said at least one wall and said at least one second wall.

9. The system of claim 8, further comprising at least one third wall disposed internally to said at least one second wall, wherein said particulate matter is disposed between said at least one second wall and said at least one third wall.

10. The system of claim 3, wherein said concave inclined segments are each configured as a segment of a circle.

11. A blast protection system for protecting structures from damage from blast shock waves created by an explosion, said system comprising:

at least one wall formed of a sheet metal and comprising multiple horizontal folds said folds comprising a generally horizontal segment and an outwardly facing inclined segment wherein the configuration of said folds is such that said wall expands in a generally upward direction when impacted by a horizontal blast shock wave; and

particulate matter disposed behind and abutting said wall, whereby said particulate matter absorbs and dissipates energy transferred through said wall;

wherein said inclined segments have a lower edge and an upper edge, and wherein said horizontal segments have a forward edge and a rear edge, and wherein said lower edge of said inclined segment is connected to said rear edge of said horizontal segment, and wherein said upper edge of said inclined segment is connected to said forward edge of said horizontal segment.

12. A blast protection system comprising:

multiple walls formed of a folded sheet metal and comprising multiple horizontal folds, said folds each comprising an exterior fold joining an upper edge of an outwardly facing inclined segment to a forward edge of a horizontal segment, and further comprising an interior junction joining a lower edge of an outwardly facing inclined segment to a rear edge of a horizontal segment;

said walls joined to form an external perimeter to retain particulate matter; and

loose particulate matter disposed behind and abutting said walls;

whereby said walls extend in a generally vertical direction when impacted by a horizontal blast shock wave.

13. The system of claim 12, wherein said particulate matter is chosen from the group of particulate matter consisting of sand, rubber particles and plastic beads.

14. The system of claim 12, further comprising footing members disposed at the bottom of said walls.

15. The system of claim 12, wherein said walls are composed of folded steel plates having a thickness of approximately ⅜ to ⅝ inches.

16. The system of claim 12, wherein said inclined segments are concave inclined segments.

17. The system of claim 16, wherein said folds further comprise a generally vertically disposed extension segment disposed between said horizontal segments and said concave inclined segments.

18. The system of claim 12, wherein said walls form a perimeter with an open top.

19. The system of claim 12, wherein said walls forming a perimeter define a set of exterior walls, and further comprising a set of interior walls of the same construction as said walls, wherein said particulate matter is disposed between said exterior walls and said interior walls.

20. The system of claim 19, further comprising a set of rear walls of the same construction as said walls, wherein said particulate matter is also disposed between said interior walls and said rear walls.

21. The system of claim 16, wherein said concave inclined segments are segments of a circle.

22. The system of claim 11, further comprising a footing member extending inwardly from said lower edge of the lowermost of said inclined segments.

23. The system of claim 11, wherein said folds further comprise a generally vertically disposed extension segment disposed between said horizontal segments and said inclined segments.

24. The system of claim 11, wherein said particulate matter is chosen from the group of particulate matter consisting of sand, rubber particles and plastic beads.