GB2078278A

GB2078278A - A Fall-out Shelter

Info

Publication number: GB2078278A
Application number: GB8118009A
Authority: GB
Original assignee: BLATCON Ltd
Current assignee: BLATCON Ltd
Priority date: 1980-06-17
Filing date: 1981-06-11
Publication date: 1982-01-06

Abstract

A strong structure for example a fall-out shelter (Figure 1) of precast concrete, is generally tubular in shape and of rectangular cross-section. The tube may be formed in one piece or of two oppositely directly channel elements 1A, 1B. The pairs U legs (2A, 2B) abut either along the shelters sides (as shown) or along its top and bottom. End slabs (3A, 3B) close the compartment. An entrance shaft is formed by an upstanding channel element (5) with upper and lower end slabs (6A, 6B). Alternatively the entrance shaft may be horizontal. Doors or hatches 48, 7 are provided. The shelter may be buried. <IMAGE>

Description

SPECIFICATION A Fall-out Shelter or Other Strong Structure This invention relates to a strong structure of precast concrete, for example a fall-out shelter, a strong-room, an electricity sub-station, or generally any other structure in which strength of construction and security are important.

An object of the invention is to provide, at a relatively low cost and using a quite simple manufacturing method, a structure which is capable of withstanding considerable overpressure and of offering good resistance to radiation.

According to this invention, a strong structure of precast concrete comprises at least a major portion which is generally tubular in construction and substantially rectangular in cross-section. The tubular part of the structure preferably includes at least one precast channel section element and may have one or both ends closed.

Thus in one form of the invention the structure comprises a pair of precast concrete, channel section elements each of substantially rectangular U-shape, one with the legs of the U extending upwardly and the other with the legs of the U extending downwardly, and with the upper element legs resting on the lower element legs, forming a tubular tunnel-like structure which is substantially rectangular in cross-section. At least one of the ends may be closed by a precast concrete slab.

In another form of the invention, the structure is the same as that described above in the first form, but the channel section elements have the abutting U legs disposed in horizontal parallel planes.

In another form of the invention the structure comprises a pair of precast concrete channelsection elements each of substantially U-shape, each element standing on one end and having the legs of its U extending in vertical parallel planes towards the legs of the U of the other element, the enclosure thus formed being preferably closed at the top by a rigid slab.

In a fourth form of the invention, the structure comprises a single channel section element of substantially rectangular U-shape, and a flat rigid slab which spans the two legs of the U, with the two elements located so that the abutting edges extend vertically or horizontally in the same manner as described above for those forms of the invention having two channel section elements.

The channel section elements and slabs may be precast in standard sizes, to provide for modular construction. End slabs may be cast integrally with the channel section elements. The lines of abutment where the ends of the U legs meet may be sealed, for example with a compressibie sealant or other known means for example mastic or surface seals. The channel section elements and slabs are preferably connected together by for example tie rods passing through the U-legs, or outside them. Door frames, hatch frames, or openings for them, may be provided as required, preferably in the end slabs.

Since the various elements are preferably modular, stocks of them would be manufactured and maintained, to permit ready supply and erection of shelters or other structures to requirements.

The invention will now be described by way of example, with reference to the drawings, in which: Figure 1 is a side elevation of a first embodiment; Figure 2 is a top plan of the first embodiment; Figure 3 is an end elevation as seen in the directionof arrow X in Figure 2; Figure 4 is a section on plane A-A of Figure 2; Figure 5 is a side elevation of a second embodiment; Figure 6 is a top plan of the second embodiment; and Figure 7 is an end elevation of the second embodiment.

Referring firstly to the embodiment of Figures 1 to 4 there is shown by way of example a fall-out shelter which comprises a pair of precast concrete, channel section elements 1 A, 1 B each of U-shape. The lower element 1 A has its legs 2A, 2A extending upwardly and the upper element 1 B has its legs 2B, 2B extending downwardly. The legs 2B, 2B abut and rest on the legs 2A, 2A, and the elements 1 A, 1 B thus form a tunnel-like tubular structure. One open end is covered by a precast concrete slab 3A and other by a precast concrete slab 3B. The slab 3A has an optional emergency escape hatch 4A with rounded corners and the slab 3B has an opening 4B with a steel surround 4C for mounting a door (not shown); again, the corners are rounded. These various rounded corners could instead be chamfered.

At the lines of abutments of the upper and lower U legs, the joints are sealed by compressible sealant. The upper and lower channel section elements are strongly held together by connecting means which are not shown but which may be for example vertical tie rods passing through the respective abutting legs, or passing along one face of the legs.

Alternatively, steel sections may extend across the lines of abutment and be welded to pieces of steel cast into the concrete of the legs for the purpose. The end slabs 3A, 3B will be connected securely to the channel section elements in a similar manner.

A third channel section element 5 stands upright on one of its ends, with the ends of its U legs 5A, 5B abutting against and connected to the slab 3B, see Figure 2. In this way an additional or entrance cell is provided; it may be used for example for decontamination. The element 5 is closed top and bottom by slabs 6A, 6B and the top slab 6A has an entrance opening 7 with rounded corners, from which opening 7 a steel stair or ladder 8 leads down into the entrance cell.

If required another cell may be provided in a similar manner at the other end of the main cell, adjacent the end slab 3A.

Alternatively the element 5 may be disposed such that the U legs 5A and 5B form, not side walls as shown in Figures 1 to 4, but the roof and floor of the extra cell, as do the elements 1 A, 1 B.

The sides of this cell may be left open; this means that, for a structure which is not sunk in the ground, this part of the structure has a blast exit so that under certain blast conditions the blast wave can escape rather than create pressure on the main door of the shelter. Arranging for the cell to have open sides would also enable several shelters to be joined together to form a larger structure in which the channel elements 5 provide a connecting passage extending along one side of the structure. Alternatively, an element 5, with legs SA, 5B arranged similarly to the legs 2A, 2B, could have an end covering slab like the slab 3A.

It is intended that the channel section elements and other parts should be made in standard sizes, so that a shelter or other structure of a required size and shape can be fabricated in a modular manner.

Holes or ducts with appropriate valves or closures may be provided for ventilation and other services. These holes or ducts are preferably in the end slabs, but may be in the other elements.

It is envisaged that the structure will be wholly or at least partly sunk in the ground.

In an alternative construction (not shown) the channel section elements would be placed so that the two abutment lines would be at top and bottom, rather than at each side. Such an arrangement may be envisaged if it is imagined that Figure 1 represents a top plan with the abutting legs 1 A, 1 B forming a horizontal, top surface of the main cell of the structure. This arrangement is preferred for a shelter or other structure having horizontal rather than vertical access, as may be the case if the structure is not wholly sunk in the ground, or if several such structures are to form a connected group.

Referring now to Figures 5 to 7, a second embodiment of fall-out shelter or other structure comprises a pair of precast concrete, channel section elements 1 OA, 1 OB each of U-shape and each standing upright on one end on a precast concrete slab 11 A. The U legs 1 2A, 1 2A, and 1 2B, 128 of the elements 1 OA, 1 OB extend in vertical parallel planes (Figure 6) and abut at vertical lines 1 3A, 1 3B. The cell thus formed is closed by a top slab 11 B. The slabs 1 A, 1 B also close the top and bottom ends of a channel section element 14 which forms an entrance cell or compartment like that shown in Figures 1, 2 and 4. Other details such as a door and openings are not shown in Figures 5 to 7 but may be similar to those described above in connection with Figures 1 to 4.

It is envisaged that the top and bottom slabs 11 B, 1 A may each serve for several cells or modules. Also if access is required horizontally (that is laterally) rather than vertically downwards (that is, from above), then one channel section element could be replaced by an angle section element, to leave an opening for a door.

Similarly, the channel section element 14 could be replaced by an angle section element to leave an opening for side access.

In modified forms of the first or second embodiments, the elements 1 A, 1 B or 1 OA, 10B may be replaced by a single tubular eiement, thus avoiding the need for the joints as shown at 1 3A and 1 3B in Fig. 6.

In all the embodiments discussed above, once the elements and siabs are connected together by rods, bolts and so on, they form a rigid, box-like structure and need only to be earth-covered to provide gamma radiation protection. To give protection against extra over-pressure, concrete may however be cast in situ around the box-like structure for even greater strength, and external surfaces of the structure may be roughened or have projecting steel elements for good bonding to the added concrete. External surfaces may be treated with water proofing solutions or may be covered with a membrane of water-proof material.

Structures made in accordance with the invention may have various advantages, as follows: 1. A modular system of construction can be formulated, in which elements of standard design can be assembled in different configurations.

2. A system of constructing heavy, strong structures is provided, using elements which are nevertheless of cranable weight.

3. A form of construction is provided which can be used to make shelters with a variety of optional access points and where there may be a number of different modules/cells according to requirements.

4. A system is provided which uses self-stable elements so that no props are needed and construction is consequently rapid.

5. A system is provided which will produce structures sufficiently strong to be preassembled at works and delivered to site ready for use.

6. The form of construction gives reasonable resistance to weapons effects.

7. The form of construction is substantially water and gas tight.

8. A system is provided which has the advantages of mass production yet may be flexible in the degree of protection it provides in - accordance with the degree of risk and the available finance.

Claims

1. A strong structure of precast concrete comprising at least a major portion which is generally tubular in construction and substantially rectangular in cross-section.

2. A structure according to claim 1 comprising a pair of precast concrete channel-section elements each of substantially rectangular Ushape, the upper element with its U legs extending upwardly and the lower element with its U legs extending downwardly, the upper element legs resting on the lower element legs forming a tubular, tunnel-like structure.

3. A structure according to claim 1 comprising a pair of precast concrete channel-section elements each of substantially rectangular Ushape, each element having its U legs extending substantially horizontally in parallel planes in abutment with the U legs of the other element and forming a tubular, tunnel-like structure.

4. A structure according to claim 2 or claim 3 wherein at least one end of the structure is closed by a concrete slab.

5. A structure according to claim 1 comprising a pair of precast concrete channel-section elements each of substantially rectangular Ushape, each element having its U legs extending substantially vertically in parallel planes in abutment with the U legs of the other element and forming a tubular structure in which the lines or planes of abutment are substantially vertical.

6. A structure according to claim 5 which is closed at least at the top by a concrete slab.

7. A structure according to claim 1 comprising a single precast concrete channel-section element of substantially rectangular U-shape, and a concrete slab spanning the open side of the channel-section element.

8. A structure according to claim 7 wherein the ends of the U-legs extend substantially horizontally.

9. A structure according to claim 7 wherein the ends of the U-legs extend substantially vertically.

10. A structure according to any preceding claim wherein at least one end slab is cast integrally with a channel-section eiement.

11. A structure according to any of claims 2 to 9 wherein elements are connected together by tie-rods passing through the U-legs.

1 2. A structure according to any of claims 2 to 9 wherein elements are connected together by tie-rods passing along one face of the U-legs.

1 3. A structure according to any preceding claim which has a main compartment and at least one end compartment.

14. A structure according to claim 1 3 wherein at least the main compartment comprises a pair of channel section elements.

1 5. A structure according to claim 14 wherein at least one end compartment comprises a single channel-section element.

1 6. A structure according to claim 14 wherein at least one end compartment comprises a pair of channel-section elements.

17. A structure according to any of claims 2 to 9 wherein elements are connected together by metallic sections extending across of lines of abutment between elements and welded to metal members cast into the elements.

1 8. A structure according to claim 1 comprising a single precast concrete tubular element of rectangular cross-section.

1 9. A strong structure connected and arranged substantially as herein described and shown in the drawings.