EP3510217B1 - Protection system for protecting buildings from airplanes crashing into them - Google Patents

Description

The invention relates to a protection system for protecting a building from aircraft crashes and similar high-energy impacts of large-volume objects according to the preamble of claim 1.

Such a protection system is from the patent DE 10 2010 037 202 B4 of HOCHTIEF Construction AG. There, to protect a structure from impacting objects in flight, a protective jacket is provided at a distance from the outer shell of the structure, the protective jacket being designed as a lattice jacket, the bars of the lattice jacket being at least partially made of steel, the protective jacket being designed as a self-supporting structure, and wherein the protective jacket is not connected to the outer shell of the building or is not connected via supporting elements. Another protection system for protecting a building from aircraft impact is in the document DE202005015904U described.

The object of the invention is to further develop a protection system of the type mentioned at the beginning in such a way that even an impact of heavy four-engine aircraft, for example of the Boeing 747 or Airbus A380 type, does not destroy the integrity of the building it is protecting.

This object is achieved according to the invention by a protection system with the features of claim 1.

It is therefore essential to the invention that the protective grille is supported on the building wall via a plurality of plastically deformable, energy-absorbing elements - and preferably exclusively via such elements. In addition, a support on the floor is advantageously provided.

The invention is based on the consideration that in departure from the in DE 10 2010 037 202 B4 disclosed technical teaching a support of the protective grille the building wall is quite desirable in order to better distribute the impact loads. A part of these loads can and should, as recognized in the context of the present invention, be absorbed by the building to be protected itself, to the extent that its structure can withstand or tolerate it without being catastrophically damaged. For this purpose, the transfer of force, pressure and deformation energy into the building wall takes place in a damped manner with the help of energy and vibration absorbing (damping) elements.

The respective energy-absorbing element advantageously comprises a tube made of steel, which is arranged between the protective grille and the building wall in such a way that the force transmitted to the protective grille when an aircraft crashes acts on the tube at least predominantly in the radial direction and, viewed in cross section, squeezes it. In contrast to conventional shock absorbers of cylindrical shape, which are installed in such a way that they are resiliently compressed in the longitudinal direction when loaded, a predominantly plastic, non-linear deformation takes place here due to a force acting in the radial direction on the circumference of the tube. To increase the energy dissipation, the tube can have a core or an installation made of crossed steel plates inside the tube.

It was possible to prove through numerical simulations that the energy-absorbing elements mentioned make a decisive contribution of up to 60% of the total energy dissipation through the protective system according to the invention and that they considerably minimize the impact-related vibrations in the building.

Advantageously, the protective grille comprises an inner lattice level formed from steel girders and arranged parallel to the building wall and an outer lattice level arranged parallel to it and formed from steel girders, the inner lattice level and the outer lattice level being connected to one another by steel girders.

In a preferred embodiment, both the inner lattice plane and the outer lattice plane comprise a regular rectangular lattice whose unit cells have the same dimensions and which are shifted from one another by half a lattice constant in at least one main direction of the lattice. It is preferred here that the inner lattice plane and the outer lattice plane are connected to one another by diagonal supports which each extend from a node point of one lattice plane to a node point of the other lattice plane.

Further advantageous embodiments emerge from the dependent claims and from the detailed description below.

FIG. 1

eine perspektivische Ansicht eines vor einer Gebäudewand installierten Schutzsystems zum Schutz des Gebäudes vor Flugzeugabstürzen,

FIG. 2

eine Draufsicht auf das Schutzsystem von oben gemäß Pfeil I in FIG. 1, darunter eine Draufsicht von vorne gemäß Pfeil II in FIG. 1, und darunter einen Querschnitt (Seitenansicht) gemäß Linie A-A,

FIG. 3

eine vergrößerte Draufsicht auf das Schutzsystem von oben, und

FIG. 4

einen Querschnitt durch ein Rohr, welches als energieabsorbierende Befestigung für das Schutzsystem an einer Gebäudewand dient, oben für sich genommen, darunter in Einbaulage des Rohrs im Schutzsystem.

An embodiment of the invention is explained below with reference to the accompanying drawings. It shows in a schematic, simplified representation:

FIG. 1

a perspective view of a protection system installed in front of a building wall to protect the building from aircraft crashes,

FIG. 2

a plan view of the protection system from above according to arrow I in FIG. 1 , including a top view from the front according to arrow II in FIG. 1 , and below a cross-section (side view) along line AA,

FIG. 3

an enlarged plan view of the protection system from above, and

FIG. 4th

a cross-section through a pipe, which serves as an energy-absorbing attachment for the protection system on a building wall, above taken by itself, below in the installation position of the pipe in the protection system.

Identical or identically acting parts are provided with the same reference symbols in all figures.

The protective system 20 shown in the figures with a protective grille 22 is set up in the manner of a protective cover in front of a building wall 24 or another section of a building envelope and protects it from aircraft crashes or similar high-energy and large-area impacts from rockets, components or debris as a result of attacks, explosions, Cyclones and the like.

The protective grille 22 is formed from interconnected, in particular welded, (steel) girders or struts or lattice bars and comprises a first lattice level facing the building wall, also referred to as the inner lattice level E1, and a second lattice level facing away from the building wall, also as the outer one Lattice plane E2. Each of the two lattice levels E1, E2 is formed by longitudinal members and cross members connected to one another, which span a preferably regular surface lattice. The two lattice planes E1, E2 are connected to one another by supports, in particular diagonal supports, arranged between them, so that a three-dimensional space lattice is implemented overall.

In the example shown here, it is assumed that the section of the building wall 24 to be protected spans a vertical plane above the floor 26. The inner lattice plane E1 is arranged parallel to the building wall 24 with the formation of a space or gap 28 with a gap width (= distance) a. The outer grid level E2 is also arranged parallel to the building wall 24 and thus also parallel to the inner grid level E1. The two grid planes E1, E2 thus form spaced apart vertical planes with a distance b.

As already mentioned, the outer lattice plane E2 is realized by a plurality of longitudinal and transverse girders which are connected to one another at the intersection or node points 30. Here in the example it concerns vertical girders 1 and horizontal girders 3. The vertical girders 1 are arranged in a columnar manner at regular intervals d from one another and aligned vertically according to their designation. The horizontal girders 3, which run perpendicular to the vertical girders 1, are aligned horizontally according to their designation and at regular intervals Distances h to one another, that is to say arranged one above the other at different heights. The horizontal girders 3 and the vertical girders 1 are preferably firmly connected to one another, in particular welded, at each of the intersection or node points 30. Overall, a regular rectangular grid is thus realized, the unit cell of which has a width d and a height h.

The inner grid level E1 is structured analogously to the outer grid level E2. It thus also forms a regular rectangular grid made of vertical beams 2 and horizontal beams 3 ', the unit cell of which preferably has the same width d and the same height h as the unit cell of the outer lattice plane E2. The distance between the two grid levels, that is to say the width or depth of the protective grid 22 is denoted by b.

The two grid levels E1, E2 are advantageously not arranged congruently one behind the other in the top view from the front, but they are shifted or offset in the horizontal direction, i.e. in the longitudinal direction of the horizontal beams 3, 3 ', preferably by half a grid width d / 2. Thus, in the projection, the nodes of the outer grid plane E2 lie in the middle between two nodes of the inner grid plane E1. In the vertical direction, however, the two grid levels E1, E2 are preferably not shifted relative to one another, so that a horizontal beam 3 'of the inner grid level E1 at the same level is assigned to each horizontal beam 3 of the outer grid level E2. This variant creates horizontal levels between the vertical grid levels E1 and E2, which can be used as floor areas. In an alternative implementation, as in FIG. 1 shown, the grid levels E1, E2 are offset from one another by half a storey height h / 2 and the vertical grid area is thereby additionally compressed.

As already mentioned, the two grid levels E1, E2 are connected to one another by additional supports, which are preferably implemented as diagonal supports 4, 5 and which are preferably connected to the nodes of the grid levels E1, E2, in particular by welding.

Specifically, here in the exemplary embodiment, four diagonal girders 4, 5 extend from each node of the outer grid plane E2 - with the exception of a few located at the edge of the grid area - to respectively assigned nodes of the inner grid plane E1. Two of the four diagonal supports, namely those with reference numeral 4, lie in a horizontal plane and extend to the two closest nodal points at the same height as the inner lattice plane E1. The other two of the four diagonal supports, namely those with reference number 5, extend spatially diagonally, namely obliquely downwards to the nodes of the inner lattice level E1 arranged directly below the aforementioned nodes (alternatively, they can also extend obliquely upwards, or in addition to the four diagonal girders mentioned, there should be two diagonal girders running upwards). As a result, the four diagonal girders 4, 5, according to the offset of the two grid levels E1, E2, fan out from the respective node point of the outer grid level E2 in a quasi star-shaped or pyramid-shaped manner and establish the connection to the inner grid level E1. Viewed from the nodes of the inner lattice level, the result is a mirror-image arrangement. Viewed from above ( FIG. 3 ) you can see a triangular partitioning. Under certain circumstances, fewer than four diagonal girders extend from the peripheral nodes due to their peripheral location.

As shown in the plan view of the protective grille 22 from above FIG. 3 As can be seen, the vertical girders 1 of the outer lattice plane E2 are preferably all arranged on the same side of the horizontal girders 3, namely preferably on the inside, that is to say directed towards the building wall 24. The same applies to the inner lattice plane E1, in which the vertical beams 2 are arranged on the inside of the horizontal beams 3 '.

The vertical supports 1, 2 are preferably integral, that is to say made from one piece, and preferably have a double-T-shaped cross section, alternatively a rectangular cross section. The same applies to the horizontal beams 3, 3 'and the diagonal beams 4, 5.

With regard to their cross-sectional width B and their cross-sectional height H, the beams are preferably dimensioned as follows: 1.2 Vertical beam W / H = 500 - 1000/500 - 1000 mm 3, 3 ' Horizontal beam W / H = 500 - 1000/500 - 1000 mm 4th Diagonal beam (horizontal) W / H = 400 - 800/400 - 800 mm 5 Diagonal beam (diagonal) W / H = 400 - 800/400 - 800+ mm

Preferred materials for the beams are types of steel with great ductility and plastic deformation capacity.

The structural dimensioning of the protective grille 22 is preferably as follows: Distance between the vertical beams d = 10 - 15 m Distance between the horizontal beams h = 5 - 10 m Width of the protective grille b = 10 - 15 m Distance of the protective grille from the building wall a = 0.3 - 2.0 m

The total height and total width of the protective grille 22 is adapted to the dimensions of the building or building section to be protected.

The protective grille 22 is preferably designed to be self-supporting and is advantageously supported by at least some, preferably all of the vertical supports 1, 2 on the floor 26. The vertical supports 1, 2 are anchored to the ground 26 in a suitable manner and are based on a foundation. The vertical supports 1, 2 can therefore also be referred to as columns or supports.

Furthermore, the protective grille 22 is connected to the building wall 24 via a plurality of shock- or energy-absorbing elements 32 or dampers. These energy-absorbing elements 24 are preferably tubes 6 or hollow cylinders made of steel, which are arranged between the protective grille 22 and the building wall 24 in such a way that, when an object hits the protective grille 22 from the front (direction of impact essentially in Direction of arrow II in FIG. 1 ) perpendicular to their longitudinal axis, that is, viewed in cross section in radial direction 34, compressed or squeezed and thereby plastically deformed.

In a preferred installation variant, the respective pipe 6 is arranged between the vertical supports 2 of the inner lattice level E1, which are directed towards the building wall 24, and the building wall 24, that is to say in the gap 28 between them. The pipe diameter D is accordingly at most as large as the gap width a. The longitudinal axis of the tube 6 is preferably arranged vertically, that is to say parallel to the vertical support 2. The pipe 6 is preferably firmly connected to the associated vertical support 2, in particular welded, on the one hand on the outer circumference, and on the other hand leaning against the building wall 24. The tube 6 then represents an energy-absorbing (connecting) element or a bracket / fastening / suspension / support or a support between the protective grille 22 and the building wall 24.

Alternatively, there can even be a gap between the building wall 24 and the pipe 6. In the latter case, it is more appropriate to simply speak of an energy-absorbing element instead of an energy-absorbing support.

However, other installation variants are also possible, in which the energy-absorbing tube 6 is fastened, for example, to a horizontal support 3 'of the inner lattice plane E1. Furthermore, a type of series or row arrangement with several parallel aligned, abutting pipes, which are arranged within the gap 28 between the inner lattice plane E1 and the building wall 24, can be realized. The required pipe length and its arrangement depends on the energy absorption requirement and depends on the (expected) impact impulse.

To increase the energy absorption capacity, a plastically deformable core 36, which preferably consists of steel plates welded together in a cross shape, is advantageously arranged in the respective tube 6. In the cross-sectional view according to FIG. 4th the core 36 forms a cross within the pipe circumference, the center of the cross coinciding with the longitudinal axis of the pipe 6. The core 36 is preferably only clamped into the tube 6 and not attached to the inner wall of the tube in any other way.

Preferred dimensions of the tubes 6 used as energy-absorbing elements are as follows: Pipe diameter D = 300 - 1000 mm Wall thickness t = 10 - 25+ mm Thickness of the plates in the core T = 10 - 50 mm

The dimensions given here and further above are tailored to the requirements for protecting a nuclear power plant building from aircraft crashes, in particular four-jet passenger planes, and have been verified in numerical simulations. The dimensioning varies in individual cases with the requirements.

Preferred materials for the tubes 6 and cores 36 are types of steel with great ductility and plastic deformation capacity

As a result of the anchoring on the foundation, part of the energy absorbed in the event of an impact or impact of an object on / into the protective grille 22 is diverted via the footrest. Another part of the energy is absorbed by the plastic deformation of the protective grille 22 itself and distributed over a larger impact surface. Furthermore, a considerable part of the energy is absorbed by the energy-absorbing elements 32, which are non-linearly deformed upon impact, and only a small part is transferred to the building in a greatly reduced form. This reduces the energy transmission to the building to be protected to an acceptable level. This ensures that the building is not structurally overloaded and that impact-related oscillations and vibrations are limited to an acceptable level. Eventually, an impacting object is broken into several small pieces of debris by the protective grille 22 disassembled, which are deflected in different directions and hit different places on the building wall 24 at a slower speed.

Finally, a particular advantage of the construction is that the entire building does not have to be surrounded, but the protective cover can be limited spatially to the particularly sensitive or sensitive sections of the building wall 24 or building envelope.

In an expedient modification of the construction described so far, the protective grille 22 can be held on the building wall 24 exclusively via the energy-absorbing elements 32, without any support on the floor, which is useful, for example, when protecting ceiling sections. The position and orientation of the protective grille 22 in the room must then of course be adapted to the installation situation. This means that the "vertical girders" and "horizontal girders" are then oriented differently in space than has been described so far and as suggested by the designation used here.

Finally, it is conceivable that the shape of the protective grille 22 corresponds to the outer contour of a building, such as a circular or otherwise curved outer circumference of a z. B. domed power station building follows. This is expediently implemented by means of straight sections, as described above, with kinks in between.

As far as steel is mentioned in the above description, this means that the component in question consists at least partially of steel. Composite materials made of steel and other materials are expressly included.

A particularly important area of application is the protection of power plant buildings or building shells of nuclear power plants or other nuclear facilities. Of course, many other applications for protection against industrial plants or military objects from aircraft crashes and the like are also possible.

List of reference symbols

1

Vertical beam

2

Vertical beam

3

Horizontal beam

3 '

Horizontal beam

4th

Diagonal beam

5

Diagonal beam

6th

pipe

20th

Protection system

22nd

Protective grille

24

Building wall

26th

ground

28

gap

30th

Junction

32

energy absorbing element

34

Radial direction

36

core

E1

inner lattice plane

E2

outer lattice plane

Claims (12)

1. A protective system (20) for protecting a building from aircraft crashes and similar high-energy impacts, having a three-dimensional protective grid (22) constructed in front of a building wall (24) at a distance therefrom and comprising interconnected supports (1 to 5),
   wherein the protective grid (22) is supported on the building wall (24) via a plurality of plastically deformable, energy-absorbing elements (32),
   characterized in that
   each energy-absorbing element (32) comprises a steel tube (6) arranged between the protective grid (22) and the building wall (24) in such a way that the force transmitted to the protective grid (22) when an aircraft strike occurs acts on the tube (6) at least predominantly in the radial direction (34) and squeezes it together in cross-section.
2. The protective system (20) according to claim 1, wherein the protective grid (22) is supported on the building wall (24) exclusively via the energy-absorbing elements (32).
3. The protective system (20) according to claim 1 or 2, wherein the diameter (D) of the tube (6) is in the range between 0.3 and 1.0 m and the thickness (t) of the tube wall is in the range between 10 and 50 mm.
4. The protective system (20) according to claim 3, wherein the tube (6) has a core (36) made of crossed steel plates inside the tube.
5. The protective system(20) according to any one of the preceding claims, wherein the protective grid (22) comprises an inner grid plane (E1) arranged parallel to the building wall (24), which inner grid plane is formed from steel supports (2, 3') and an outer grid plane (E2) arranged parallel thereto, which is formed from steel supports (1, 3), wherein the inner grid plane (E1) and the outer grid plane (E2) are interconnected by steel supports (4, 5).
6. The protective system (20) according to claim 5, wherein the distance (b) of the two grid planes (E1, E2) from one another is in the range between 10 and 15 m.
7. The protective system (20) according to claim 5 or 6, wherein both the inner grid plane (E1) as well as the outer grid plane (E2) comprise a regular rectangular grid, the elementary cells of which have the same dimensions (d, h) and which are displaced relative to one another at least in one direction by half a grid constant (d/2).
8. The protective system (20) according to claim 7, wherein the width (d) of the elementary cell is in the range between 10 and 15 m, and the height (h) of the elementary cell is in the range between 5 and 10 m.
9. The protective system (20) according to claim 7 or 8, wherein the inner grid plane (E1) and the outer grid plane (E2) are connected to one another by means of diagonal supports (4, 5), which in each case extend from a node point (30) of one grid plane (E1) to a node point (30) of the other grid plane (E2).
10. The protective system (20) according to any one of the preceding claims, wherein the protective grid (22) is supported on the bottom (26) by means of a plurality of supports (1, 2).
11. The protective system (20) according to any one of the preceding claims, wherein the supports (1 to 5) of the protective grid (22) have a double T-shaped or rectangular cross section, the dimensions of which are in the range between 400 and 1000 mm.
12. The protective system (20) according to any one of the preceding claims, wherein the distance (a) of the protective grid (22) from the building wall (24) is in the range between 0.3 to 2.0 m.

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