WO2014041525A2

WO2014041525A2 - Device, system and method for increasing the earthquake resistance of buildings

Info

Publication number: WO2014041525A2
Application number: PCT/IB2013/058579
Authority: WO
Inventors: Luca Pirazzini
Original assignee: Regola S.R.L.
Priority date: 2012-09-17
Filing date: 2013-09-16
Publication date: 2014-03-20
Also published as: ITBO20120485A1; WO2014041525A3

Abstract

A device (1) for increasing the earthquake resistance of a building comprises elements (2A.2B) subjectable to elasto-plastic deformation and having at least one hollow member (8A,8B) intended to be deformed along a predetermined axis of deformation (D2) and which can be constrained in use to an upright column (C) and to a crossbeam (T) positioned on the upright column (C) slidably at least along the axis of deformation (D2), the elements (2A.2B) subjectable to elasto-plastic deformation being configured in such a way that, in use, the at least one hollow member (8A,8B) can be compressed and deformed elastically along the predetermined axis of deformation (D2) as a result of a displacement of the crossbeam (T) on the column (C) up to a first predetermined displacement value, and can be compressed and deformed plastically and irreversibly along the predetermined axis of deformation (D2) as a result of a displacement of the crossbeam (T) on the column (C) greater than the first predetermined displacement value in such a way as to absorb energy deriving from the action of the earthquake, thus limiting the displacement of the crossbeam (T) on the column (C).

Description

DESCRIPTION

DEVICE, SYSTEM AND METHOD FOR INCREASING THE

EARTHQUAKE RESISTANCE OF BUILDINGS

Technical field

This invention relates to an anti-seismic device for increasing the earthquake resistance of buildings and to a method and system for increasing the earthquake resistance of buildings.

Background art

It should be noted that in this description, the term "buildings" means any type of building construction, in particular, factory sheds, farm sheds, etc. A factory building usually consists of a plurality of upright columns which support corresponding beams which in turn support the roof of the building.

Each upright column supports one or more beams which rest freely on the column.

It has been noted that during an earthquake, the beams are displaced relative to the top surface of the column which supports it.

The displacement of the beam relative to the top supporting surface of the column reduces the contact surface between the beam itself and the top surface of the column.

Particularly in the case of very strong earthquakes, the displacement may be so large that the beam comes right off the top of the column which supports it, with the risk of collapse and dangerous consequences for the safety of the occupants of the building.

The displacement of the beam on the column is caused mainly by the undulatory component of the shock waves but also by a sussultatory component, which increases the intensity of the displacement, in practice reducing the friction between the underside of the beam and the top surface of the column (which the beam rests on). Anti-seismic systems are known which are configured to rigidly constrain the beam to the column in such a way that the beam is not displaced on the column. These systems, however, require means of strengthening the base of the column to which the stress generated by the shock waves are transmitted.

These systems are therefore particularly complex and expensive and cannot guarantee building safety.

There is therefore a strongly felt need for a safety device which is capable of increasing the earthquake resistance of buildings, reducing the risk of buildings collapsing during an earthquake.

Disclosure of the invention

This invention therefore has for an aim to overcome these disadvantages by providing a device, a system and a method for increasing the earthquake resistance of buildings.

Another aim of the invention is to propose a method for increasing the earthquake resistance of buildings and which can be easily applied to existing buildings.

Yet another aim of the invention is to propose a device and a method for increasing the earthquake resistance of buildings and which are particularly simple and inexpensive.

According to the invention, these aims are achieved by a device, a system and a method comprising the technical features set out in one or more of the annexed claims.

Brief description of the drawings

The technical features of the invention, with reference to the above aims, are clearly described in the annexed claims and its advantages are more apparent from the detailed description which follows, with reference to the accompanying drawings which illustrate a preferred, non-limiting embodiment of the invention and in which: - Figures 1 and 2 are, respectively a side view and a perspective view of the device according to this invention, for increasing the earthquake resistance of buildings;

- Figure 3 shows an application of the device of the preceding figures, for increasing building safety;

- Figure 4 is a sectional view of the device of Figure 3;

- Figure 5 is a perspective view of a detail from the preceding figures;

- Figure 6 shows a hollow member which forms part of the safety device and which has been deformed as a result of an earthquake;

- Figure 7 shows a hollow member forming part of the safety device and in a condition where it is still intact, that is to say, not deformed;

- Figure 8 illustrates a further embodiment of the safety device according to the invention. Detailed description of preferred embodiments of the invention

In the accompanying drawings, the reference numeral 1 denotes a device for increasing the earthquake resistance of buildings.

The device, as will become clearer as this description continues, defines an anti-seismic system 10 capable of increasing the resistance of buildings to seismic shocks.

The device 1 is applicable to a crossbeam T which is supported freely by a column C (or post C).

The device 1 , in the specific embodiment illustrated, comprises a first hollow member 8A for limiting the displacement of the crossbeam T relative to the column C along an axis of displacement D1 in a first direction T1 and a second hollow member 8B for limiting the displacement of the crossbeam T relative to the column C along the axis of displacement D1 in a second direction 12, opposite the first direction T1. The expression "hollow member" is used to mean a part with one (or more than one) internal cavity.

According to the invention, the elasto-plastic deformation means (2A,2B) are configured in such a way that, in use, the hollow members (8A.8B) can be compressed and deformed elastically as a result of a displacement of the crossbeam T on the column C up to a first predetermined displacement value, and can be compressed and deformed plastically and irreversibly as a result of a displacement of the crossbeam T on the column C greater than the first predetermined displacement value in such a way as to absorb earthquake energy, thus limiting the displacement of the crossbeam T on the column C.

The expression "displacement value" is used to mean a length by which the crossbeam T is displaced relative to the column C, measured from the initial position of the crossbeam T (its mounting position, that is, its position before the earthquake).

Preferably, each hollow member (8A.8B) comprises a first layer 4 of metallic material.

Preferably, the first layer 4 comprises steel.

Still more preferably, each hollow member (8A,8B) also comprises a second layer 5 of polymer matrix composite material and long-fibre.

The expression "long fibre" is used to mean a fibre at least greater than 1 cm in length. The long fibre is preferably carbon fibre, and/or glass fibre, and/or basalt fibre, and/or aramid fibre, and/or high-density polyethylene, and/or polyester, and/or polypropylene, and/or polyamide and metal.

The long fibre may be arranged in more than one layer and in at least one of the layers is arranged at angles of between 90 and 30 degrees to the axis of deformation D2.

In one preferred embodiment, the second layer 5 is a layer of carbon fibre. It should be noted that, preferably, the first layer 4 of metallic material is positioned on the inside, whilst the second layer 5 of composite material is positioned on the outside and covers the first layer 4.

The hollow member (8A,8B), therefore is preferably tubular in shape, with the first and second layers (4 and 5) defining the walls of the lateral surface of the member itself. Still more preferably, the hollow member (8A.8B) is cylindrical in shape: advantageously, this shape guarantees optimal, uniform deformation of the hollow member (8A.8B) because the hollow member (8A,8B) does not have corners or sharp edges which could create abnormal stresses during the operation of the device 1 .

Figure 7 shows one of the hollow members (8A,8B) in a configuration of normal use, that is, where it is not permanently deformed.

Figure 6, on the other hand, shows one of the hollow members (8A,8B) when it is permanently deformed (for example, as a result of a strong earthquake).

The device 1 also comprises a plurality of abutment elements (6) (the drawing shows four abutment elements, labelled 6A,6B,6C and 6D).

One of the abutment elements 6 is illustrated in Figure 5.

It should be noted that each of the abutment elements 6 is configured to be coupled to one end of a hollow member (8A,8B).

More specifically, each of the abutment elements 6 has an abutment portion 15 shaped to be inserted into the hollow member (8A,8B).

The technical effect of the abutment elements 6 is better clarified and defined below, where the operation of the invention is explained.

It should be noted that, in more general terms, the abutment elements 6 define abutment means 6 which can be associated with the ends of each hollow member 8.

The abutment elements 6 are configured to come into abutment with, and stop the displacement of, the crossbeam T on the column C if compression of the hollow members (8A,8B) corresponds to a displacement of the crossbeam T relative to the column C greater than a second predetermined displacement value (where the second value is greater than the first displacement value).

It should also be noted that each abutment element (6A,6B,6C,6D) comprises a central opening 14 for the passage of the means 7 for connecting and supporting the first hollow member 8A and the second hollow member 8B (the means 7 also form part of the device 1 ).

In more general terms, the hollow members (8A,8B) define, according to the invention, means (2A,2B) subjectable to elasto-plastic deformation - hereinafter also referred to as elasto-plastic deformation means (2A,2B),

5 which can be constrained (preferably fastened), in use, to an upright column C and which can be coupled (connected) in use to a crossbeam T which is freely supported on the upright column C (with the possibility of moving in the supporting plane along at least one axis of sliding).

Also in more general terms, it should be noted that the elasto-plastic l o deformation means (2A,2B) can be fastened to one of either the column C or the crossbeam T and can be connected to the other of either the column C or the crossbeam T.

It should also be noted that the elasto-plastic deformation means (2A,2B) are operatively constrained to both the upright column C and the 15 crossbeam T.

It should be noted that according to the invention an anti-seismic system 10 is defined which comprises:

- a device 1 as described above, for implementing the earthquake safety of buildings;

0 - means 1 1 for fastening the elasto-plastic deformation means (2A.2B) to an upright column C;

- means (12) for coupling the elasto-plastic deformation means (2A,2B) to a crossbeam T freely supported on the upright column C and configured in such a way as to compress and elastically deform the at least one hollow5 member (8A,8B) as a result of a displacement of the crossbeam T on the column C up to a first predetermined displacement value and to deform the at least one hollow member (8A.8B) plastically and irreversibly as a result of a displacement of the crossbeam T on the column C greater than the first predetermined displacement value in such a way as to absorb0 earthquake energy and thus limit the displacement of the crossbeam T on the column C. As illustrated in Figure 3, the hollow members (8A,8B) are positioned with their main axis of extension D2 (axis of symmetry) substantially parallel to a direction of displacement D1 of the crossbeam T relative to the column C, in such a way as to be compressed and deformed as a result of a displacement of the crossbeam T relative to the column C in at least one direction (T1 ,T2) of the axis of displacement D1 of the crossbeam T.

It should be noted that the hollow members (8A,8B) are designed to be deformed along a predetermined axis of deformation D2 (preferably coinciding with their main axis of extension, that is, their axis),

Described below is a preferred embodiment of the invention with reference to Figure 3.

Figure 3 illustrates an application of the device 1 to a building, in particular to a crossbeam T freely supported on a column C.

It should be noted that the crossbeam T is freely supported on the column C slidably at least along the axis labelled D1.

The device 1 comprises the two hollow members 8A and 8B which are connected to each other and supported by a bar 20 (preferably threaded at least at the ends of it).

A plate, labelled 12, is connected to the crossbeam T and is interposed between the two hollow members 8A and 8B.

The plate 12 forms part of the means 12 for coupling the elasto-plastic deformation means to the crossbeam T.

It should be noted, in particular, that the plate 12 has a cavity 21 through which the threaded bar 20 is inserted and can pass freely.

It should be noted that when the crossbeam T is displaced relative to the column C, the plate 12 can slide along the threaded bar 20 so as to compress one and/or the other of the two hollow members (8A.8B).

A nut (22A.22B) is coupled to each end of the threaded bar 20.

The nuts (22A.22B) and the threaded bar 20 together define the aforementioned means 7 for connecting and supporting the tubular members (8A.8B). It should be noted that screwing the nuts (22A.22B) onto the threaded bar 20 allows fastening (rigidly connecting) the threaded bar 20 to the column C so that it is substantially prevented from moving along the axis of displacement D1 of the crossbeam T.

More specifically, screwing the nuts (22A,22B) onto the threaded bar 20 makes it possible to prevent movement of one end of the hollow members (8A.8B) along the selfsame bar 20.

More specifically, it should be noted that the displacement of the crossbeam T on the column C along the axis D1 during an earthquake causes the plate 12 to be displaced along the same axis D1 : the displacement of the plate 12 along the axis D1 compresses the first hollow member 8A if displacement is in the direction T1 or the second hollow member 8B if displacement is in the opposite direction T2.

It should be noted that the compression of the first hollow member 8A and/or of the second hollow member 8B causes irreversible plastic or elastic deformation of the hollow members (8A,8B), as a function of the extent of the displacement of the crossbeam T relative to the column C, as follows:

I) if the extent of displacement is less than the first displacement value, deformation of one and/or the other of the hollow members (8A,8B) occurs in the elastic range;

II) if the extent of displacement is greater than the first displacement value, deformation of one and/or the other of the hollow members (8A,8B) occurs in the plastic range, that is, irreversibly, as illustrated in Figure 6 with reference to one hollow member.

Further, if the displacement is greater than the second displacement value, the abutment elements (6A,6B,6C,6D) at the ends of the hollow member (8A.8B) which was compressed as a result of displacement of the crossbeam T, come into abutment with each other, thereby preventing and stopping the displacement of the crossbeam T in the direction (T1 ,T2) which caused the hollow member (8A.8B) to be compressed. With reference to the maximum size of deformation of the hollow members (8A,8B), it should be noted that, generally speaking, the size of elastic deformation is greater than 0% and less than 15% of the maximum extent of deformation of the hollow members (8A.8B), whilst the size of plastic deformation accounts for the rest.

The maximum size of deformation of the hollow members (8A,8B) substantially coincides with the second value of displacement of the crossbeam T, at which the deformation of the hollow members (8A,8B) and the displacement of the crossbeam T relative to the column C come to a stop.

As regards situation I) above, it should be stressed that this situation applies to low magnitude earthquakes and does not require substitution of any component of the device 1 because the hollow member/members is/are deformed elastically.

Situation II), on the other hand, arises as a result of earthquakes of magnitude greater than the earthquakes of situation I), and requires substitution of the hollow members (8A,8B) because the hollow members are caused to be deformed irreversibly.

The elastic and/or plastic deformation of the hollow member (8A,8B) enables earthquake energy to be absorbed, thus limiting the displacement of the crossbeam T on the column C (along the axis D1 ) and thereby preventing the crossbeam from being detached from its support, that is to say, from falling off the top surface of the column C.

This increases the safety of the building and reduces the risk of serious structural damage to the building in the event of earthquakes.

It should also be noted that, according to the invention, the device 1 absorbs energy in situation II) thanks to the permanent deformation of some of its components (the hollow members 8A,8B), thus preventing the crossbeam T from losing the support provided by the column C: this increases the safety of buildings by preventing the crossbeam T from being detached from the column C. It should also be noted that, advantageously, the device 1 can be applied easily and at a relatively low cost to existing buildings, too: in other words, the device 1 can be used to make existing buildings safe at limited costs and in an extremely short space of time.

It should also be noted that, according to the invention, the original static scheme is not modified in any way.

It should also be noted that the hollow members 8A and 8B must be substituted when an earthquake causes them to be deformed irreversibly. As regards the fact that each hollow member (8A,8B) comprises a first layer 4 of metallic material and a second layer 5 of composite material, attention is drawn to the following.

Advantageously, the combination of the first layer 4 of metallic material and the second layer 5 of composite material guarantees substantially uniform behaviour of the hollow member (8A,8B) over the full range of deformation of the hollow member (8A,8B).

More specifically, the combination of the first layer 4 of metallic material and the second layer 5 of composite material makes it possible to avoid unwanted variations of behaviour in the passage from linear to plastic deformation of the hollow member (8A,8B), thus improving the performance of the device 1.

It should also be noted that the abutment means/elements 6 allow the displacement of the crossbeam T relative to the column C to be limited to a predetermined maximum value, corresponding to the second displacement value of the crossbeam T at which the abutment elements 6 come into abutment with each other.

In effect, when one of the two hollow members 8A,8B is compressed on account of the crossbeam being displaced to the extent of the second predetermined displacement value, the abutment elements (6A,6B,6C,6D) associated therewith, located at opposite ends of the hollow member itself, come into contact and thus substantially prevent any further deformation of the hollow members (8A,8B). In other words, contact of the abutment elements 6 with each other increases the rigidity of the device 1 , defining a rigid constraint between the crossbeam T and the column C.

Described below with reference to Figure 8 is an alternative embodiment of the safety device 1.

In particular, it should be noted that in this variant embodiment, the safety device 1 comprises means for coupling the device 1 to the fastening means 1 1 and which are configured to move the device 1 relative to the fastening means 1 1.

Preferably, these coupling means (also referred to as first coupling means) are configured to allow one or more components of the safety device 1 to be rotated about one or more centres of spatial rotation.

As may be observed in particular in Figure 8, these coupling means comprise a first pair of elements including a first element 25A having a spherical surface and a second element 26A having a spherical surface designed to mate with the spherical surface of the first element.

The first element 25A and the second element 26A are interposed between the nut 22A and the fastening means 1 1 . The threaded bar 20 passes freely through them.

It should also be noted that a pressure fitted element 27A is provided by which the second element 26A is pressure fitted to the fastening means 1 1.

The above mentioned first coupling means also comprise a third element 25B, also having a spherical surface, like the first element 25A, and a fourth element 26B, also having a spherical surface designed to mate with the spherical surface of the third element.

The third element 25B and the fourth element 26B are interposed between the fastening means 1 1 and the second hollow member 8B. The threaded bar 20 passes freely through them.

It should be noted, therefore, that the above mentioned coupling means are associated with both sides of the plate 1 1 of the fastening means 1 1 . At the plate 12, there are further coupling means, referred to as second coupling means.

In the specific embodiment illustrated, the second coupling means comprise a fifth element 25C, having a spherical surface, and a sixth element 26C, having a spherical surface shaped to mate with the spherical surface of the fifth element 25C, both located on a first side of the plate 12C.

It should also be noted that a pressure fitted element 27A is provided by which the sixth element 26C is pressure fitted to the means 12 for coupling the elasto-plastic deformation means (2A.2B) to the crossbeam T.

These coupling means also comprise a seventh element 25D, having a spherical surface, and an eighth element 26D, having a spherical surface shaped to mate with the spherical surface of the seventh element 25D, both located on a second side of the plate 12C, opposite to the first side. It should be noted, therefore, that the above mentioned coupling means (25C,26C,25D,26D) are operatively coupled to both sides of the plate 12. Advantageously, the device 1 configured as described above is particularly effective and guarantees the effectiveness of the device 1 against the earthquake even if the main axis of extension of the hollow member (8A.8B) is not exactly aligned with the axis of displacement (D1 ) of the crossbeam.

Preferably, these coupling means (25A,26A,25B,26B,25C,26C,25D,26D) are configured to allow one or more components of the safety device 1 to be rotated about one or more centres of spatial rotation.

According to the invention a method is also defined for increasing the earthquake resistance of buildings comprising at least one crossbeam T slidably supported on an upright column C.

The method comprises the following steps:

- preparing elasto-plastic deformation means (2A,2B) (of the type described above); - fastening the plastic deformation means (2A.2B) to the upright column C;

- coupling the plastic deformation means (2A.2B) to the crossbeam T to compress and deform at least one hollow member (8A.8B) elastically as a result of a displacement of the crossbeam T on the column C up to a first predetermined displacement value, and to deform the at least one hollow member (8A,8B) plastically and irreversibly as a result of a displacement of the crossbeam T on the column C greater than the first predetermined displacement value in such a way as to absorb earthquake energy, thus limiting the displacement of the crossbeam T on the column C.

In an embodiment not illustrated, the device 1 comprises at least one hollow member (8A,8B) which has a portion that delimits, in a section plane at right angles to the axis of deformation D2 a surface whose size is variable along that predetermined axis of deformation D2.

Preferably, the absolute size of the variation value of the surface of that portion is less than around 20% of the mean surface area of the hollow member (8A,8B) delimited in a section plane at right angles to the axis of deformation D2 along that predetermined axis D2.

In other embodiments not illustrated, this portion which delimits, in a section plane at right angles to the axis of deformation D2 a surface whose size is variable along that predetermined axis of deformation D2, has, on the external and/or internal surface of the hollow, tubular member (8A,8B), radial recesses which define a variation of the surface delimited in a section plane at right angles to the axis of deformation D2 along that predetermined axis D2.

According to this aspect, in more general terms, it should be noted that the device 1 comprises at least one hollow member (8A,8B) having radial recesses on the external and/or internal surface of the hollow, tubular member (8A,8B). These recesses may be cavities, slots, holes, etc.

The recesses may be formed in one or more longitudinal portions of the hollow member (8A,8B).

Preferably, the recesses are arranged symmetrically about the axis of the hollow member (8A.8B).

Advantageously, the radial recesses are such that the anti-seismic system 10 has a uniform behaviour in use, that is, during deformation (in particular in the passage from elastic to plastic deformation).

Preferably, this portion has a tapered shape.

It should be noted that the device 1 can be applied to an upright column C and to a crossbeam T individually or in combination with other devices 1. Advantageously, if two or more devices 1 are applied to an upright column C and to a crossbeam T, they may be coupled to the crossbeam T and to the column C in such a way as to be deformed along different axes.

Advantageously, therefore, the displacements of the crossbeam T relative to the column C can be limited along a plurality of axes.

The invention described is susceptible of industrial application and may be modified and adapted in several ways without thereby departing from the scope of the inventive concept. Moreover, all the details of the invention may be substituted for technically equivalent elements.

Claims

1. A device (1 ) for increasing the earthquake resistance of a building, characterized in that it comprises elements (2A,2B) subjectable to elasto- plastic deformation and having at least one hollow member (8A,8B) intended to be deformed along a predetermined axis of deformation (D2) and which can be constrained in use to an upright column (C) and to a crossbeam (T) positioned on the upright column (C) slidably at least along the axis of deformation (D2), the elements (2A,2B) subjectable to elasto- plastic deformation being configured in such a way that, in use, the at least one hollow member (8A,8B) can be compressed and deformed elastically along the predetermined axis of deformation (D2) as a result of a displacement of the crossbeam (T) on the column (C) up to a first predetermined displacement value, and can be compressed and deformed plastically and irreversibly along the predetermined axis of deformation (D2) as a result of a displacement of the crossbeam (T) on the column (C) greater than the first predetermined displacement value in such a way as to absorb energy deriving from the action of the earthquake, thus limiting the displacement of the crossbeam (T) on the column (C).

2. The device according to claim 1 , wherein the at least one hollow member (8A,8B) is cylindrical.

3. The device according to either of the preceding claims, wherein the at least one hollow member (8A,8B) is tubular.

4. The device according to any of the preceding claims, wherein the at least one hollow member (8A,8B) has a portion that delimits, in a section plane at right angles to the axis of deformation (D2), a surface whose size is variable along the predetermined axis of deformation (D2), the absolute size of the variation value of the surface of that portion being less than approximately 20% of the mean surface area of the hollow member (8A.8B) delimited in a section plane at right angles to the axis of deformation (D2), along the predetermined axis (D2).

5. The device according to any of the preceding claims, wherein the hollow member (8) comprises at least one layer (4) of metallic material such as steel, iron and iron alloys, aluminium and aluminium alloys.

6. The device according to any of the preceding claims, wherein the hollow member (8A,8B) comprises at least one layer (5) of polymer matrix composite material and long-fibre.

7. The device according to the preceding claim, wherein the long fibre is preferably carbon fibre, and/or glass fibre, and/or basalt fibre, and/or aramid fibre, and/or high-density polyethylene, and/or polyester, and/or polypropylene, and/or polyamide and metal.

8. The device according to claim 6 or 7, wherein the long fibre may be arranged in more than one layer and in at least one of the layers is arranged at angles of between 30 and 90 sexagesimal degrees to the axis of deformation (D2).

9. The device according to claim 5 and any of the claims 6 or 7 or 8, wherein the layer (5) of composite material is coupled to the metallic layer (4) and arranged on the outside of the metallic layer (4).

10. The device according to any of the preceding claims, wherein the elements (2A.2B) subjectable to elasto-plastic deformation comprise:

- a first hollow member (8A) for limiting the displacement of the crossbeam (T) relative to the column (C) in a first direction (T1 ) along the axis of deformation (D2);

- a second hollow member (8B) for limiting the displacement of the crossbeam (T) relative to the column (C) in a second direction (T2), opposite the first direction (T1 ), along the axis of deformation (D2) and wherein the device (1 ) comprises means (7) for connecting and supporting the first hollow member (8A) and the second hollow member (8B).

1 1. The device according to any of the preceding claims, wherein the hollow member (8A,8B) comprises abutment means (6) associated with the ends of the hollow member (8A,8B) and configured to come into abutment with, and stop the displacement of, the crossbeam (T) on the column (C) if the displacement of the crossbeam (T) relative to the column (C) is greater than a second predetermined displacement value.

12. The device according to the preceding claim, wherein the abutment means (6) comprise a plurality of abutment elements (6A,6B,6C,6D) having an abutment portion (15) shaped to be inserted into the hollow member (8A.8B).

13. The device according to the preceding claim, wherein each abutment element (6A,6B,6C,6D) comprises a central opening (14) for the passage of the means (7) for connecting and supporting the first member (8A) and the second member (8B).

14. An earthquake-proof system (10), comprising:

- a device (1 ) for implementing the earthquake safety of buildings according to any of the preceding claims;

- means (1 1 ) for fastening the elements (2A,2B) subjectable to elasto- plastic deformation to an upright column (C);

- means (12) for coupling the elements (2A.2B) subjectable to elasto- plastic deformation to a crossbeam (T) supported on the upright column (C) slidably along the axis of deformation.

15. The system according to claim 14, comprising first spherical coupling means (25A,26A,25B,26B,27A) interposed between the coupling means (12) and the at least one hollow member (8A,8B) to allow the hollow member (8A,8B) to rotate at least partially relative to the crossbeam (T) or column (C) and second spherical coupling means (25C,26C,25D,26D,27C) interposed between the fastening means (1 1 ) and the at least one hollow member (8A,8B) to allow the hollow member (8A,8B) to rotate at least partially relative to the crossbeam (T) or column (C).

16. A method for increasing the earthquake resistance of buildings comprising at least one crossbeam (T) supported freely on an upright column (C), characterized in that it comprises the following steps:

- preparing elements (2A.2B) subjectable to elasto-plastic deformation and having at least one hollow member (8A.8B) designed to be deformed along a predetermined axis of deformation (D2);

- constraining the plastic deformation means (2A.2B) to the upright column

(C);

- constraining the elements (2A,2B) subjectable to plastic deformation to the crossbeam (T), in order to compress and elastically deform the at least one hollow member (8A,8B) along the predetermined axis of deformation (D2) as a result of a displacement of the crossbeam (T) on the column (C) up to a first predetermined displacement value, and deform the at least one hollow member (8A,8B) plastically and irreversibly along the predetermined axis of deformation (D2) as a result of a displacement of the crossbeam (T) on the column (C) greater than the first predetermined displacement value in such a way as to limit the displacement of the crossbeam (T) on the column (C).