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Title:
APPARATUS FOR ISOLATING BUILDINGS, BRIDGES AND OTHER STRUCTURES FROM SEISMIC HORIZONTAL COMPONENTS
Document Type and Number:
WIPO Patent Application WO/2007/099478
Kind Code:
A2
Abstract:
Apparatus for isolating buildings, bridges and other structures from seismic horizontal components, in which the structure to isolate (19) and its substructure (18), directly exposed to the kinetic energy of the earthquakes, are separated one from the other by interposing an adequate number of mechanical isolators among them. Each of mechanical isolators includes a roller (1) or a ball (30) positioned between two opposite rolling channel-shaped races (2A, 31A) with a concave longitudinal section and with a transversal section that coincides with the generatrix of the rolling element. Most of all, they are ready to quickly and automatically orientate towards the horizontal direction of the seism since they are disposed radially in the rotating fifth wheels (2, 31) of two bearings that, suitable to support high axial, and also radial, loads, are identical but staggered and have their rotation axes parallel to the vertical passing, in a state of rest, through the centre of both the rolling channel-shaped races (2A, 31A) and the rolling element (1, 30), which remains there for gravity.

Inventors:
MICALI ALDO ANTONINO (IT)
Application Number:
PCT/IB2007/050556
Publication Date:
September 07, 2007
Filing Date:
February 21, 2007
Export Citation:
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Assignee:
MICALI ALDO ANTONINO (IT)
International Classes:
E02D27/34; E04H9/02
Domestic Patent References:
WO2005031088A22005-04-07
Foreign References:
US2014643A1935-09-17
JP2005264580A2005-09-29
JPH11117991A1999-04-27
Attorney, Agent or Firm:
MANZELLA, Giovanni (Via Nosadella 9, Bologna, IT)
Download PDF:
Claims:

Claims

[1] Apparatus for isolating buildings, bridges and others structures from seismic horizontal components, characterised in that the structure to isolate (19) and its substructure (18), directly exposed to the kinetic energy of the earthquakes, are separated one from the other by interposing an adequate number of mechanical isolators among them, each of said mechanical isolators including a roller (1) or a ball (30) positioned between two opposite rolling channel-shaped races (2A, 31A) with a concave longitudinal section and with a transversal section that coincides with the generatrix of the rolling element, being said channel- shaped races suited to quickly and automatically orientate towards the horizontal direction of the seism since they are disposed radially in the rotating fifth wheels (2, 31) of two bearings suitable to support high axial and radial loads, being said bearings identical but staggered and having their rotation axes parallel to the vertical passing, in a state of rest, through the centre of both the rolling channel- shaped races (2A, 31A) and the rolling element (1, 30), which remains there for gravity.

[2] Apparatus as in claim 1, characterised in that the maximum depth of the two rolling channel- shaped races (2A, 31A) is lower or equal to the maximum radius of the rolling element (1, 30) positioned inside them to separate, in a state of rest, the two bearings of the isolator and therefore their corresponding rolling fifth wheels (2, 31), which the mentioned races belong to.

[3] Apparatus as in the previous claims, characterised in that the two fifth wheels (2, 31) of each of the two bearings, one of whose is fixed, since it is fastened to one of the two structures to separate and the other is rotating, since the rolling channel- shaped race is arranged for the rolling element interposed between the two bearings, are separated one from the other by a ring of conical rollers (8) or other suitable rolling elements. Said rolling elements, adequately spaced out through an apposite cage (6), keep the two mentioned fifth wheels (2, 7) reciprocally and revolvingly fastened to clamp the ring of conical rollers (8) or other suitable rolling elements interposed between them.

[4] Apparatus as in claim 3, characterised in that the balls ring (5) is positioned, together with its spacer cage (6), in a circular opening (7C) created in the middle of the fifth wheel (7) and it is clamped between the apposite annular narrowing of the same opening and the annular widening

of an element (4) that, by entering this opening (7C), holds in one of its frustum-pyramidal cavities the corresponding protuberance (2D) in the fifth wheel (2) to which it is fastened with a ordinary screw profitably excluded, thanks to this coupling, from any shearing stress and also from unscrewing.

[5] Apparatus as in the previous claims, characterized in that some special hook supports (2B, 7B), identical but orientated the ones against the others, protrude laterally from the corresponding fifth wheels (2,7) of each bearing of the isolator to allow, when needed, their reciprocal locking through a frontal insertion, on each couple of supports (2B, 7B) vertically aligned, of a rectangular collar (10) kept there through a rectangular plate (11) trans- versally inserted in the opposite vertical notches of the same supports and therefore fastened through one or two screws (12) inserted in the coinciding holes of the same plate (11) and of the collar at the back (19).

[6] Apparatus as in claim 5, characterized in that further couples of hook supports (2C), identical with the supports (2B) but orientated towards the opposite direction to those of the same fifth wheel, protrude from the rolling fifth wheels (2, 7) of the two overlapped bearings so that they can be fastened, two by two and in vertically aligned couples, through the frontal insertion of a rectangular collar (10) fixed there, as in claim 5, by a transversal plate (11) and by one or two screws (12).

[7] Apparatus as in the previous claims, characterized in that the horizontal surfaces of the isolated structure and of the substructure where to fasten the fifth wheels (2, 7) of the two bearings of an isolator are formed by a steel, or other suitable material, plate (16) supplied with slots (16A) connected with the same amount of boxes (17) that, fastened against the back face of the plates (16) and equipped with some oblique wings (17A) for a more steady anchorage of the concrete mix are destined to the anchoring elements (13, 14) with whom to hook the boundary protrusions (7A) of the fixed fifth wheels.

[8] Apparatus as in claim 7, characterized in that the element (13) is made of a cylindrical body (13A) from whose opposite ends trans versally protrude, towards the same direction, the teeth (13B, 13C) that, after the insertion of the end with the tooth (13C) in one of the slots (16A), complete the anchorage of the fifth wheels (7) with a rotation of about 90°.

[9] Apparatus as in claim 8, characterized in that to lock the element (13) in an anchorage set-up, and also to assist it during the shearing stresses imposed by the horizontal shocks of the seism, this element is supported by

a catch (14) made of a cylindrical body (14A) with the same diameter and of a perforated tooth (14B), which transversally protrudes.

[10] Apparatus as in claims 8 and 9, characterized in that from the cylindrical body (13A) of the element (13) a portion (13D) protrudes transversally. Said portion has two thicknesses in order to lean partly against the external face of the plate (16) and partly on the tooth (14B) of the catch (14) to surmount by avoiding the cylindrical body (14A) to allow to fasten, in this anchorage set-up, the two elements through the insertion of a screw (15) in the corresponding holes of the two overlapped portions and of which one, at least, is threaded.

[11] Apparatus as in claim 7, characterised in that, when the moulding of the plinths (18A) of the substructure is performed in their use location, the plate (16) shows an opening (16B) in the middle through which the concrete mix can be poured in till the complete filling of the mould coated with the same plate.

[12] Apparatus as in claim 1, characterized in that at least two couples of jacks (Ml) and (M2), arranged to horizontally converge each couple in a single connection (25), act simultaneously between the substructure (18) and two points of the isolated structure (19) until they impose on it the maximum shift allowed by the rolling channel- shaped bearings, which are thus forced to automatically orientate towards the same direction imposed to them at the beginning so that, as soon as the action of these jacks (Ml) and (M2) stops, the concave longitudinal section of the rolling channel- shaped races of the roller (1) and the force of gravity can perfectly restore the coincidence of the two races and also the exact planimetic position of the isolated structure (19) at the beginning.

[13] Apparatus as in claim 12, characterised in that it allows, when needed, the inspection and replacement of the isolators since, thanks to the concavity of the rolling channel-shaped races of the roller, the nearly horizontal shift imposed to the isolated structure (19) by the two or more couples of jacks (Ml) and (M2) is matched to an elevation of the same structure enough to temporarily prop it near the isolator to remove and replace.

[14] Apparatus as in the claims 12 and 13, characterized in that each of the two jacks (Ml) and (M2) is fastened to the substructure (18), in particular to the stirrup (27) fixed to the retaining wall (18B), through a Cardan joint (28) that allows the jack to rotate from a state of rest to the hooking set-up in the connection formed by the perforated stirrup (25) together with the

pivot (26), an also to accompany the following elevation of the structure (19).

[15] Apparatus as in claim 14, characterized in that the jacks (Ml) and (M2) are steadily fastened each onto a sort of trolley (29) that facilitates their motion providing them also with that horizontality or other set-up anyway necessary to perfectly fit in the perforated stirrup (25) with a simple flat rotation from a state of rest to the use set-up.

[16] Apparatus as in one or more of the previous claims, characterized in that, in order to exclude even the most unlikely possibility of accidental release of the rollers (1) from the isolators, which are the rolling channel- shaped races of the bearings (Ci) and (Cs) between which they are interposed, some portions of the isolated structure (19) are cantilevered surmounted, or even better crossed over by horizontal portions of the substructure (18).

[17] Apparatus as in claim 16, characterized in that the distance between the portions of the substructure (18) that surmount cantilevered or overlap those of the isolated structure (19) is enough to allow this isolated structure only the elevation consequential to the relative maximum horizontal shift of the two bearings of an isolator in order to exclude the possibility of wider shifts or of jolts, which could allow the mentioned rollers (1) to exit the corresponding rolling channel- shaped races.

[18] Apparatus as in the claims 16 and 17, characterized in that the horizontal portions of the substructure (18) and of the isolated structure (19) that cross over are protected, on the surfaces exposed to reciprocal collisions and sliding, by interchangeable shields (20), in metal or other suitable material and with a rubber layer on the inside (21), that are arranged like a saddle on the lower horizontal portion and hooked to the upper one to accompany the collisions without damages.

[19] Apparatus as in one or more of the previous claims, characterized in that the interchangeable plugs (23), destined for size and material to yield only to high intensity strains such as those of a seism, are inserted in the vertically aligned clearance holes of the elements (18C) and of the beams underneath (19B), where they remain, thanks to a transversal pin (23A) or another suitable device, to prevent the isolated structure from oscillating for the wind pressure or other non-seismic strains.

[20] Apparatus as in the claim 19, characterized in that the crossing over portions of the two structures, equipped or not with shields (20) and rubber layers (21), show each two vertical holes coated and arranged in a way that the interchangeable plugs (23) inserted in them are more or less in the

middle of the crossed portion and placed alongside the two vertical faces of the other portion so fitted in.

[21] Apparatus as in one or more of the previous claims, characterized in that the rolling fifth wheels (2) of an isolator, those containing a roller (1) or a ball (30), show, in a state of rest, one or more reciprocal points of contact that prevent the upper bearing from oscillating on the rolling element even without impeding the other relative predictable and necessary movements.

[22] Apparatus as in all the previous claims, characterized in that wedges and shims are interposed between the rolling fifth wheels (2) of the two bearings, especially during the phase of construction of the structure to isolate, or even interchangeable rubber or other suitable materials linings are interposed between the rolling fifth wheel (2) of the two bearing sealing the opening formed by the corresponding rolling channel- shaped races.

Description:

Description

APPARATUS FOR ISOLATING BUILDINGS, BRIDGES AND OTHER STRUCTURES FROM SEISMIC HORIZONTAL

COMPONENTS

Technical Field

[1] The following invention regards an apparatus for isolating buildings, bridges and other structures from seismic horizontal components.

Background Art

[2] The techniques of seismic isolation consist, on the whole, in prearranging, between the structure to isolate and the substructure integral with the ground, an adequate amount of 'isolators' generally equipped with a high rigidity for vertical loads but not for the horizontal ones aiming to preserve the upper structure from the horizontal seismic strains which are the most damaging.

[3] At present, there are three kinds of seismic isolators corresponding to as many construction techniques: isolators of elastomeric material and steel; elastoplastic isolators; sliding or rolling isolators.

[4] The isolator of elastomeric material and steel are composed of rubber layers or other suitable materials and steel plates, which have the function to restrain the elastomer decreasing its deformability for vertical loads and instead leaving it highly deformable for horizontal loads.

[5] The elastoplastic isolators are composed of elements that conserve their elasticity in the presence of vertical loads and, instead, they plasticize in the presence of horizontal actions exceeding a prefixed threshold.

[6] The sliding or rolling isolators , composed respectively of steel and Teflon supports and of roller or ball supports, are all characterized by low data of the frictional resistance. Therefore, while for elastoplastic isolators and for those of elastomeric material and steel, the damping needed to contain the relative shifting of the two separated structures, is assured by the highly hysteretic behaviour of the material they are made of, for the sliding isolators and for the rolling ones it is instead necessary to arrange, in parallel, appropriate energy dissipators.

[7] Some dissipators, called viscous-elastic, exploit the viscous behaviours of materials such as plastic materials, mineral oils and silicone. Other dissipators, called elastoplastic, exploit the plasticization of metallic material to dissipate the energy in hysteresis loops. Finally, the so-called friction dissipators take advantage of the friction between appropriately treated and relatively sliding metallic surfaces.

[8] To purposes of durability are relevant not only the ageing of the elastomers

(rubbers) and of the thermoplastic polymers (Teflon) but also the physical and chemical characteristics of the adhesives used to glue the steel sheets to the rubber, as well as those of the linear-chain silicon organic polymers (silicone oils and grease) used in the viscous-elastic dissipators placed, if necessary, in parallel to the sliding or rolling isolators.

[9] It is also necessary to consider that the elastoplastic isolators and those made of elastomeric material and steel are particularly vulnerable in the event of fire and have to be adequately protected from this occurrence or provided with some devices that can substitute them in case of destruction.

[10] The rolling mechanical isolators described in the italian patent no. 1146596 inthe name of Micali are less problematic, from this point of view. In fact, they are entirely realised in steel or other suitable rigid material and composed each by a couple of concave circular elements with a ball interposed between them, whose diameter has not to be shorter than the sum of the two heights of the concavity. According to this patent, by setting the concave elements into two beds or reinforced-concrete reticular structures that stand one directly on the ground and the other on the balls, only the bed or the lower reticular structure has to undergo possible horizontal seismic shocks of the ground. On the other hand, the upper one, thanks to the rolling of the underlying balls, can accompany the inertia of rest of the building and remain almost still, since it is forced only to the modest vertical translations due to the temporary shifting of the lower concave elements relative to the upper ones set in it. The only limitation of these rolling mechanical isolators concerns the compression resistance of the balls due to the exiguous contact with the related concave rolling housings and the consequent necessity of large numbers or big dimensions.

Disclosure

[11] The aim of the present invention is to resolve the above-mentioned drawbacks by devising an apparatus for isolating buildings, bridges and others structures from seismic horizontal components which combine the values of a rolling mechanical isolator with the benefits of a higher compression resistance that, in the same conditions, allows to limit the number and/or the dimensions of the isolators upon which the structure to isolate can be laid.

[12] Such a peculiarity is even unavoidable when the height of the structure to isolate, in relation to its overall plan dimensions, is such as to require, at the base, such a multitude of rolling isolators of the old type that they make it difficult, if not impossible, their positioning while functioning, respecting the fact that 'the housing of the isolators and their connection to the structure have to be conceived so that access to them is ensured and the isolators themselves can be inspected and replaced', according to Ministerial Decree 16/11/1996, point Bl, with regard to the guidelines of National

Council of Public Works for the design, the building and the testing of seismic isolated structures.

[13] Considering the explained requirements, the invention analyzed, designed to exclude buildings, bridges and other structures from any horizontal component of a seism, propose that the structure to isolate and the underlying structure exposed to the kinetic energy of the earthquakes, are separated by interposing between them an adequate number of mechanical isolators. Each of said mechanical isolators is composed by a roller or a ball stationing between two opposite rolling channel-shaped races, which have a concave longitudinal section and a transversal section that matches with the generatrix of the rolling element. But, most of all, these races are ready to quickly and automatically orientate towards the horizontal direction of the seism. This is possible because they are arranged radially in the rotating fifth wheels of two bearings that, suited to support high axial and radial loads, are identical but staggered and with the respective axis of rotation parallel to the vertical passing, in a state of rest, through the centre of both the channel- shaped rolling races and of the rolling element that remains there for gravity.

[14] Therefore, the horizontal shakes imposed by the seism on the structure integral with the ground, together with the rest inertia of the isolated upper structure, determine the immediate automatic orientation of the rolling channel-shaped races of the isolators towards the same direction of the seism and, if necessary, even the rolling of the rolling elements of said races in relation to the residual relative movement of the two structures.

Description of Drawings

[15] Description details of the invention shall be further evident in the illustrations of a preferred type of the apparatus for isolating buildings, bridges and others structures from seismic horizontal components , in the guideline drawings attached and wherein:

[16] figures 1, 2, 3, 4, 5, 6 illustrate a rolling isolator created according to a preferred form of realization of the planned system and here showed, locked in transport and storing set-up, with six pictures including, respectively, a first lateral view, the view from the top, the vertical section AA, another side view, the horizontal section BB and the vertical section CC;

[17] figure 7 illustrates a lateral view of the isolator with two bearings reciprocally locked in the correct use set-up and the plinth of the substructure to which anchor the isolator;

[18] figure 8 illustrates the view from the top DD of the plinth of the substructure equipped with an anchor plate for the isolator;

[19] figures 9 and 10 illustrate the view from the top partially sectioned in EE and the vertical section FF of the isolator together with the plinth of the structure to which it is

anchored and with the anchor plate on which to directly build the plinth of the upper structure to isolate;

[20] figure 11 illustrates four views of the hook for anchoring the isolator in its use location;

[21] figure 12 illustrates three views of the catch to lock the hook in picture 11 in anchorage set-up;

[22] figures 13 and 14 illustrate the view from the top of the lower bearing anchored to the plinth of the substructure and the lateral exploded view of this ensemble;

[23] figures 15 and 16 illustrate, through the vertical section GG and the horizontal section HH, the seismic behaviour of the examined isolator and its anchorage to the two structures with the hooks and their respective catches of the type shown in fig. 11 and 12;

[24] figures 17, 18, 19, 20 illustrate, schematically, a sequence of the behaviour of the two bearings of the isolator of the pictures above in the presence of parallel seismic shocks to the rolling channel-shaped races of the roller;

[25] figures 21, 22, 23, 24 illustrate a sequence of the behaviour of the two bearings of the isolator above during oblique and perpendicular seismic shocks to the rolling channel-shaped races of the roller and during their subsequent re-centering;

[26] figures 25, 26, 27, 28, 29 illustrate, through three vertical sections NN and two horizontal sections OO of the portion of a building isolated according to the invented system, the devices to prevent the exit of the rollers that separate the bearings. Also, the figures show the way of using the jacks which, by performing the lateral shifting of the isolated structure and its consequent elevation due to the concavity of the rolling channel-shaped races, allow the inspection and the replacement of the isolators. Furthermore, said jacks determine, when necessary, the re-centering of the bearings according to figures 22, 23, 24;

[27] figures 30, 31, 32 illustrate in detail, through a view from the top and the vertical sections PP and QQ, an horizontal portion of the substructure that crosses over a beam of the isolated structure;

[28] figures 33 and 34 illustrate, in the order and during a seismic strain, the vertical section LL and the horizontal section MM of a rolling isolator created according to a possible form of realization that has a ball as rolling element;

[29] figures 35, 36, 37 illustrate, schematically, a sequence of the behaviour of the two bearings of the isolator in fig. 33 and 34 while parallel seismic shocks take place to the rolling channel- shaped races of the ball;

[30] figures 38, 39, 40, 41, 42 illustrate a sequence of the behaviour of the two bearings of the previous isolator while oblique or perpendicular seismic shocks take place to the rolling channel- shaped races and during their subsequent re-centering.

Best Mode

[31] With reference to Figures 3, 6, 10, 15, which illustrate the vertical sections of the isolator to which the attached first seven pictures refer, a cylindrical roller 1 is placed inside two opposite rolling channel- shaped races 2A whose longitudinal section is concave while the transversal one matches with the generatrix of the above mentioned roller.

[32] The above-mentioned channel- shaped races 2A are arranged radially in the rotating fifth wheels 2 of two overlapped bearings, created to support high axial and radial loads, since they are meant for the support of the upper structure and also for the isolation of the structure itself from the horizontal component of a seism. These bearings are identical but staggered and their rotation axes are parallel to the vertical that, in a state of rest, passes through the centre of both the two channel-shaped races 2A and of the roll 1 that stays there for gravity.

[33] The rotating fifth wheel 2 and the still one 7 of both the two bearings of an isolator are separated by a ring of conical rollers 8 whose axes, thanks to the rolling races arranged in the two fifth wheels, are orientated to perpendicularly converge to the rotation axe of the bearing. This allows also the use of another spacer cage 9, perfectly flat, that can be obtained by simply cutting a plate of the appropriate material.

[34] Clearly the above-mentioned conical rollers 8 are suited to withstand the axial strains while the balls ring 5 is intended for the radial ones. The balls ring 5 also has the function to keep the fifth wheel 2 and 7 reciprocally and revoltingly restrained to clamp the ring of conical rollers 8 interposed between them.

[35] In fact, the balls ring 5, placed together with its cylindrical spacer cage 6 in a circular opening 7C operated in the middle of the fifth wheel 7, is clamped between the fitting annular narrowing of the same opening and the annular widening of an element 4. This, by entering inside the mentioned opening, holds in one of its frustum- pyramidal cavities the corresponding protuberance 2D in the fifth wheel 2 to which it is simply fastened with a screw 3, appropriately excluded, thanks to this matching, from any possible shearing stress and also from unscrewing.

[36] As we can deduct especially from fig. 1, 3, 7, 10, some specific hook supports 2B and 7B, identical but oriented towards each other, protrude laterally from the fifth wheel 2 and 7 of each bearing of the isolator in order to allow the reciprocal locking with the aid of some rectangular collars 10 and of some rectangular plates 11.

[37] Basically, each couple of hook supports 2B and 7B vertically aligned holds the frontal insertion of a rectangular collar 10. This is hold there by a rectangular plate 11, transversely inserted in the opposite vertical cavities of the same supports and therefore fastened with one or two screws 12 inserted in the corresponding holes of the same plate 11 and of the collar 10 at the back.

[38] On this subject, it is sufficient that only one of the two coinciding holes, involved with the same screw 12, is threaded.

[39] Since during the transport, the storage and the laying of the isolator, nonetheless during the construction of the upper structure to isolate, it is needed the reciprocal locking of the two bearings of each isolator too, there are further hook supports 2C that stick out from the rotating fifth wheel 2 as well. These supports 2C, though, are oriented towards the opposite direction from the supports 2B, since, in this case, the couples of supports are vertically aligned but they belong to the fifth wheel 2 of two overlapped bearings. The supports 2C are constrained in couples with the frontal insertion of a rectangular collar 10 fastened there, as in the couples of supports 2B and 7B, with a transversal plate 11 and with one or two screws 12.

[40] About the hook supports 2B and 2C of the rotating fifth wheel 2, it is to underline that their arrangement is such that it allows the locking of each bearing, and of the whole isolator, both in the storage and transport set-up as in fig. 1, 3 and 6 and in the use set-up in fig. 7 and 10 too.

[41] Even if after the construction of the upper structure to isolate the upper bearings of the isolators anchored to said structureare forced to a sort of complanarity and to the verticality of their rotation axis, before the rigid connection of all the isolators it may happen that the only reciprocal locking of the two bearings obliquely to the rolling channel-shaped races, as in fig. 7 and 9, is not enough to prevent from a swing, even a small one, of the upper bearing on the roller 1. This can be avoided with the aid of two suitable wedges or shims to interpose between the two fifth wheels 2 of the two bearings during the transport, the storage and most of all during the construction of the upper structure to isolate.

[42] Since the relative movement of the two bearings, thanks to the concave longitudinal section of the rolling races of the roller, determines the contemporary lifting of the upper bearing, it is not impossible that the rotating fifth wheels 2 of an isolator, which are the ones that contain the roller, can be shaped to have, in a state of rest, some points of reciprocal contact which prevent the upper bearing from swinging on roller 1 even without opposing the relative movement allowed to the two bearings thanks to the rolling of the roller itself in the channel- shaped races 2A.

[43] Furthermore it could be possible to achieve the same aim with some interchangeable linings of suitable material (antifriction material, plastics, rubber or else) applied along the perimeter to seal or nearly, in a state of rest, the opening formed by the two rolling channel- shaped races of the roller.

[44] Since it is necessary to take into consideration the possible need to remove and quickly replace the isolators installed, for their fastening while functioning, which is to fasten them to the plinths 18A of the substructure 18 and underneath the corresponding

plinths 19A of the structure 19 to isolate, it is contemplated the use of the anchorage equipments 13 and 14, in tables 4 and 6. This allows to steadily and simultaneously hook the boundary protuberances 7 A of the fifth wheel 7 and the adjacent metal plates 16, which coat the horizontal base of the mentioned plinth and are provided, with this aim, with an appropriate number of slots 16A connected with as many boxes 17, fastened against the lower face of the plates 16 and preferably equipped with oblique wings 17A (figures 9, 10, 15) for a more steady anchorage of the concrete mix.

[45] It is important to underline that, if the reinforced concrete plinths were moulded in their use location, the plate 16 of the lower plinths 18A would have, as in figures 7 and 8, an opening 16B in the centre through which to pour the concrete mix till the complete filling of the mould coated with the plate itself.

[46] Instead, as shown in fig. 9 and 10, the moulding of the upper plinths 19A requires an earlier fastening of the plate 16 to the isolator locked in use set-up and completed by the moulding of a mould that has the above-mentioned plate 16 as disposable bottom.

[47] From a detailed analysis of the anchorage equipments 13 and 14 in tables 4 and 6, element 13 results made of a cylindrical body 13A from whose opposed ends stretch themselves trans vers ally, in the same direction, the teeth 13B and 13C that, after the insertion of the end with teeth 13C in one of the slots 16 A, achieve the anchorage of the fifth wheel 7 through a simple rotation of about 90°.

[48] To lock the aforesaid element 13 in anchorage set-up and also to facilitate it during the shearing stresses imposed by the horizontal shocks of the seism, the element is supported by a catch 14 made of a cylindrical body 14A of the same diameter and of a perforated tooth 14B that protrude transversally. Thanks to this catch, from the cylindrical body 13A of the element 13 also a portion 13D with two thicknesses protrudes transversally, since it has to lean partly against the external face of plate 16 and partly on the teeth 14B of the latch 14 to surmount by avoiding the cylindrical body 14A.

[49] The insertion of a screw 15 in the matching holes of the two overlapped portions, of which at least one is threaded, allows fastening the hook and its corresponding catch in the anchorage set-up shown in fig. 13 and 15.

[50] The mechanical behaviour of the described isolator is represented in sequence in the figures of table 7 where there are schematized: the lower bearing Ci, which is the one anchored to the substructure 18 and directly exposed to the telluric movements of the ground; the upper bearing Cs, which is the one anchored below the isolated structure 19; the roller 1, which is the rolling element interposed between the two bearings and situated inside the respective rolling channel- shaped races marked with Pi, the one of the lower bearing Ci and with PS, the one of the upper bearing Cs.

[51] In a state of rest (fig. 17) the upper bearing Cs of each isolator is staggered from the lower bearing Ci, while the two rolling channel-shaped races Ps and Pi, which

contain the cylindrical roller 1 and are set in the fifth wheels 2 of the mentioned bearings, are reciprocally facing, which means they coincide in horizontal projection.

[52] In case of seismic shocks S parallel to the above-mentioned rolling channel-shaped races, these maintain their orientation unaltered, as in fig. 18 and 19, while the rolling of the roller 1 allows the isolated structure to accompany its inertia of rest and the lower bearing Ci moves together with the ground, in one direction or the other, compared to the upper bearing Cs that remains relatively still.

[53] Thanks to the concave longitudinal section of the two rolling channel-shaped races, when the telluric movement stops (fig. 20) the two bearings are kept in the same set-up as before the seism. Consequently they are ready to neutralize the horizontal components of any further telluric movement.

[54] In case of seismic shocks S oblique, or even perpendicular to the rolling channel- shaped races, the rectilinear horizontal movement of the ground with the lower bearings Cs, together with the inertia of rest of the structure isolated through the upper bearings Cs, determine the simultaneous rotation of the fifth wheels 2 of the two bearings of each isolator forced by the roller 1 to orientate the respective rolling channel-shaped races Pi and Ps towards the direction defined each time by the position of the two mentioned bearings, as shown in fig. 20 and 21. From these we can also deduce the temporary linear translation of the lower bearing Cl towards the same direction taken by the two roller channel- shaped races. Once the seismic shocks stop (fig. 22) the two bearings of each isolator automatically restore only the so-called coincidence of the respective rolling channel- shaped races but not the previous orientation shown in fig. 20.

[55] The reinstatement of the initial orientation of the rolling channel-shaped races, irrelevant for the performance of the isolators, is useful only to bring the isolated structure back to the exact planimetric position it had at the beginning.

[56] On this subject, as indicated in fig. 23 and even better in fig. 8, 9, 10, the invented system requires the intervention of at least two couples of jacks Ml and M2. These, arranged so that each couple can converge horizontally in the same connection 25, operate simultaneously between the substructure 18 and the two points of the isolated structure 19 till they impose upon it the maximum possible shift allowed to the rolling channel-shaped races, which are forced to automatically orientate towards the same direction imposed on them at the beginning. Therefore, once the action of the jacks Ml and M2 stops, the concave longitudinal section of the rolling channel- shaped races of the roller 1, together with the force of gravity, perfectly restore the so-called coincidence of the two races and even the exact planimetric position of the structure 19 at the beginning (fig. 17-24).

[57] Interventions like the one described above allow, when needed, the inspections and

the potential solutions proposed in above mentioned Ministerial Decree 16/11/1996, point Bl.

[58] In fact, thanks to the concavity of the rolling channel- shaped races, the nearly horizontal movement imposed upon the isolated structure 19 by the two or more couples of jacks Ml and M2 is matched with an elevation of the same structure high enough to be able to temporarily prop it in proximity to the potential isolator to remove and replace. Possibly, this should be performed with the aid of a suitable trolley to be arranged underneath the upper bearing Cs before the release of the plinth 19A and its repositioning on the lower bearing Ci to be removed together.

[59] Even without excluding other devices and ways to obtain the described shift of the isolated structure 19 for inspection and possible replacement of the isolators, the invention propose that each of the two jacks Ml and M2, as illustrated in fig. 25, 26, 27, 28, 29, is fastened to the substructure 18, in particular to the stirrup 27 fixed to the breast wall 18B, through a Cardan joint 28, to allow the jack to rotate from the state of rest in fig. 26 to the hooking set-up in the connection formed by the perforated stirrup 25 and by the pin 26, as well as to accompany the following elevation of the structure 19 as in fig. 29.

[60] Each of these jacks is steadily fastened to a sort of trolley 29, which facilitates its motion providing it also with that horizontality or other set-up that is anyway necessary to perfectly fit in the perforated stirrup 25 with a simple flat rotation.

[61] It is granted, at this point, that the orientation of the isolators at work and the positioning of the couples of jacks Ml and M2 are interdependent and necessarily prearranged during the designing phase of the structure to isolate.

[62] From the same figures which illustrate the couple of jacks Ml and M2, we can deduct that some portions of the isolated structure 19, in particular the beams 19B, are crossed over by horizontal portions 18C of the substructure 18. This is meant to exclude the most remote possibility of accidental release of the rollers 1 of the isolators, which means the exit of the bearings Ci and Cs from the rolling channel- shaped races they are interposed to.

[63] The distance of the aforesaid portions 18C from the beams below 19B is enough to allow the isolated structure 19 just the consequential elevation to the maximum horizontal relative shift of the two bearings of an isolator (fig. 29), in order to exclude the eventuality of wider shifts or jolts that can allow the rollers 1 to exit their rolling channel-shaped races.

[64] About the crossing over of the beams 19B of the isolated structure by horizontal portions 18C of the substructure, the figures in tables 8, 9, 10 and in particular figures 30, 31, 32 show that the areas of the two elements 19B and 18C exposed to possible reciprocal collisions or sliding are shielded by a sort of interchangeable shield 20,

preferably metallic and with a rubber layer 21 on the inside. This shield 20, which can be arranged on the beams 19B as a saddle, in the elements above 18C is inserted from the bottom and kept there by four rotating hooks 22 that, by hooking the two upper edges of these elements 18C, allow the shield to translate vertically without damages, in case the rubber layer 21 was compressed by the temporary elevation of the beam below 19B.

[65] In order to prevent the isolated structure from oscillating for the wind pressure and other non-seismic strains, it is designed the presence of interchangeable plugs 23 that, destined for size and material to yield only to high frequency strains such as those of a seism, are inserted into the vertically aligned clearance holes of the elements 18C and of the beams below 19B, where they remain thanks to a transversal pin 23A or another element that protrudes laterally from the upper end of these plugs in order to prevent the downward slip for falling.

[66] According to what is illustrated in the figures, both the element 18C and the beam below 19B have two vertical clearance holes. These should preferably be coated and arranged in a way that the interchangeable plugs 23 inserted in them are in the middle of the portion crossed and placed alongside with the two vertical faces of the other portion so fitted in.

[67] While the interchangeable plugs 23 crossing the horizontal elements 18C are hold by a transversal pin 23A inserted to protrude near the upper end, the plugs 23 crossing the beams 19B of the isolated structure are fastened by a transversal pin 23 A crossing, in this case, the lower end of this plug and also the cylindrical covering 24 protruding with it from the lower face of the beam 19B.

[68] Clearly, all the operations that require the functioning of the jacks Ml and M2 to the momentary shifting of the isolated structure 19, are preceded, as in fig. 27, by the temporary removal of all the plugs 23 or at least of those that could buck this shift.

[69] From all that has been analyzed so far it is clear that when the rolling element interposed between the two bearings of an isolator is the roller 1, this forces the two rolling channel- shaped races 2 A to keep the same orientation compelling the two respective fifth wheels 2 to simultaneously rotate during the shift of any of the two bearings towards a direction that does not coincide with the one of the mentioned rolling runner- shape races.

[70] In case, as in the variant shown in tables 11 and 12, the rolling element is the ball

30, the corresponding rolling channel- shaped races 3 IA, arranged in the rotating fifth wheels 31 of the two bearings of the isolator, can take different orientations, even reciprocally perpendicular ones as in fig. 33.

[71] In this case too, as in the version already explained, in a state of rest (fig. 35) the upper bearing Cs of each isolator is staggered in comparison to the lower bearing Ci.

Instead, the rolling channel- shaped races Ps and Pi, containing the ball 30 and arranged in the rotating fifth wheels 31 of these bearings, are facing each other, which means they coincide in horizontal projection.

[72] In the presence of seismic shocks S parallel to the mentioned rolling channel- shaped races, these, as in fig. 36 and 37, maintain unaltered their orientation while the rolling of the ball 30 allows the isolated structure to accompany its own inertia of rest and the lower bearing Ci moves together with the ground, in one direction or the other, in comparison to the upper bearing Cs relatively still. Therefore, thanks to the concave longitudinal section of the two rolling channel- shaped races, once the telluric movement stops (fig. 38) the two bearings are in the same position as before the seism and consequently they are ready to neutralize the horizontal components of any further telluric movement.

[73] In the presence of seismic shocks S oblique or even perpendicular to the rolling channel-shaped races Pi and Ps (fig. 39) these take different orientations one from the other till the shift of the lower bearing Ci, in comparison to the upper one Cs, is such that it forces the two races towards the same orientation to the alignment of the ball 30 with the centre of the two bearings.

[74] Since in the example in fig. 39 the seismic shift of the lower bearings Ci is not wide enough to determine the alignment of the two rolling channel-shaped races, when the telluric movement ends (fig. 40) the upper race Ps automatically restore, thanks to gravity, its centring on the ball 30 while this places itself in the middle of the lower race Pi.

[75] The coincidence of the two rolling channel- shaped races and their previous orientation (fig. 38) are still to be reinstated though. On this subject, as indicated in fig. 41 and also described about the previous version, at least two couples of jacks Ml and M2 work between the substructure and the isolated structure imposing on the latter and to the two upper bearings Cs the maximum shift allowed by the two channel- shaped races Ps and Pi and also the aligned orientation of these towards the same direction imposed on them at the beginning (fig. 41).

[76] After the couples of jacks Ml and M2 operate, the concave longitudinal section of the rolling channel-shaped races of the ball 30, together with the force of gravity, perfectly restore the coincidence of the two races and also the exact planimetric position of the isolated structure at the beginning (fig. 35, 42).

[77] It is clear that the invented system, it being understood the overall illustrated and described characteristics, could be susceptible to possible changes and variants included within this patent anyway. These modifications could concern, among the rest, the replacement of the rolling elements of the bearings with others of different shapes or with sliding steel and Teflon supports or other suitable antifriction materials.

[78] Materials adopted for the actual realization of the invention, as well as their shapes and sizes, can be various, depending on the requirements.

[79] Where technical features mentioned in any claim are followed by reference signs, those reference signs have been included for the sole purpose of increasing the intelligibility of the claims and accordingly, such reference signs do not have any limiting effect on the scope of each element identified by way of example by such reference signs.