DESCRIPTION rOOOIlTechnical field

[0002]The object of the present invention is a seismic isolation foundation system and method for buildings, for example residential, industrial, military structures and infrastructures. The invention relates to a seismic isolation system and method for constructing foundations, which is particularly adapted to existing buildings which structure is not adequate for seismic events or for increased horizontal dynamic loads. r00031Backqround art

[0004]ln the field of residential engineering and architecture, the expression "seismic isolation" means the construction features serving to isolate the load-bearing structure of the buildings from the effects of an earthquake, in general from the effects of dynamic horizontal seisms of the ground on which the buildings are founded. Similarly, the expression "seismic isolators" means those devices adapted to isolate the load-bearing structure of the buildings from the effects of an earthquake or any horizontal vibration of the ground.

[0005]The essential functional features of seismic isolators are their increased horizontal shear deformability which allows a related horizontal movement between the above-ground structure and the foundation. Isolators may also have a damping effect capable of dissipating a part of the movement energy.

[0006]By interposing seismic isolators between the foundations and above-ground structures, the frequencies of the seism are uncoupled from the natural frequencies of the above-ground structure, thus avoiding the occurrence of phenomena of resonance and/or significant dynamic amplifications. Thereby, during a seism, the isolated structure behaves almost as a rigid body which tends to remain stationary with respect to an absolute reference system, which implies an action of rigid motion with respect to the foundation ground and a drastic reduction of the actions on the isolated structure.

[0007]The reduction of the horizontal forces acting on the above-ground structure and accordingly, on the foundation, is due on the one hand to the possibility of related horizontal movement, and therefore to the increase of the fundamental period of the isolated structure, and on the other, to the damping of a part of the movement energy.

[0008]Elastomeric isolators having high vertical rigidity and low horizontal rigidity which allows bringing the period of the isolated structure to fields in which the acceleration induced by earthquakes is very low, are known among the various isolation devices. Elastomeric isolators consist of a (low or high damping) elastomer isolation body reinforced with metal sheets, and sometimes they may be provided with a lead core which is inserted in the isolation body to increase the capability thereof to dissipate energy.

[0009]Moreover, "sliding" isolators are known; they are generally activated by obtaining a (generally very low) threshold value of the horizontal forces acting on the structure. Known sliding isolators include, for example, isolators sliding on flat surfaces with sliding friction (e.g. steel-Teflon) with or without lubrication, isolators sliding over round surfaces which allow an auto-recentering of the structure after the seism, as well as metal rolling isolators.

[0010]For newly constructed buildings, the installation of seismic isolators during construction is easy, very efficient and well-tested.

[0011]On the other hand, there are currently no satisfactory solutions for the problem of the seismic isolation of existing buildings. The implementation of conventional seismic isolators below existing buildings is so complicated and costly that it has only been tried in an experimental manner on small buildings. Therefore, the problem is highly relevant, especially in areas where there are buildings which are not adapted to support seismic loads.

[0012]The use of so-called "micropiles" for shielding and reinforcing the foundations of existing buildings is very common. With reference to residential engineering, the micropile is a foundation pile having dimensions conventionally ranging between 90 mm and 300 mm in diameter.

[0013]Foundation systems with micropiles do not require large working and storage spaces and therefore are often used in urban settings by virtue of the limited invasiveness of the equipment required for constructing them, which may also be carried out in rooms.

[0014]The individual micropile has a lower load-bearing capacity than a pile having a medium or large diameter, pile length and ground stratigraphy being equal, but using a sufficient quantity and length of micropiles makes it possible to obtain a stable support.

[0015]The installation of micropiles comprises making a perforation in the ground, inserting a metal reinforcement tube in the perforation in the ground, injecting a consolidation mixture of cement or pressurized resin into and externally to the reinforcement upright, and connecting (anchoring) the head of the micropile to the building.

[0016]A disadvantage of the micropile is the poor resistance thereof to shear stresses, in particular forces transmitted horizontally to the head of the piles originating from the above ground structures, during horizontal actions such as earthquakes.

[00171Qbiect of the invention

[0018]lt is the object of the present invention to provide a seismic isolation foundation system and method which is particularly suitable for seismically isolating existing buildings.

[0019]lt is a further object of the invention to provide a foundation system and method for buildings by means of micropiles, which is capable of obviating the drawbacks due to the poor resistance to shear stresses of the micropiles themselves.

[0020]lt is a further object of the invention to provide a seismic isolation foundation system and method for buildings which is simple to install and service.

[0021 ISummarv description of the invention

[0022]At least some of these goals are achieved by means of a seismic isolation foundation system for buildings according to claim 1 and by a seismic isolation foundation method for buildings according to claim 13.

[0023]Dependent claims relate to preferred and advantageous embodiments.

[0024]According to an aspect of the invention, a foundation system with seismic isolation for buildings comprises:

A) a (preferably metal) reinforcement upright adapted to be inserted into a perforation in the ground for the construction of a foundation with micropiles; said reinforcement upright defines a longitudinal axis and comprises:

- a plurality of upright segments each having two opposite ends each forming an upright connection portion which is connectable to a corresponding upright connection portion of an adjacent upright segment,

B) a seismic isolation device defining a central axis and comprising:

- a lower support body and an upper support body,

- an isolating body which is shear deformable in a direction transverse or perpendicular to the central axis, said isolating body being fastened to and interposed between the lower support body and the upper support body so as to allow a relative movement between the upper support body and the lower support body in the direction transverse to the central axis, in which the lower support body and the upper support body each form an isolator connection portion which is connectable to the upright connection portion, for a connection of the seismic isolation device between the adjacent ends of two of said upright segments so that the central axis and the longitudinal axis are parallel or concentric.

[0025]By virtue of the interposition of the seismic isolation device between two upright segments of the reinforcement upright of the micropile, damage to the micropile in case of horizontal stresses during earthquakes is effectively obviated without the need to increase the resistance to shear stresses of the individual upright segments.

[0026]Moreover, again by virtue of the interposition of the seismic isolation device between two upright segments of the reinforcement upright, the micropile thus configured may serve as antiseismic foundation and may be employed to seismically isolate especially existing buildings, thus taking advantage of the ease and versatility of execution of the micropile foundations.

[0027]According to a further aspect of the invention, a foundation method with seismic isolation for a building comprises the steps of:

A) constructing a foundation with micropiles by:

- assembling a (preferably metal) reinforcement upright defining a longitudinal axis, by connecting a plurality of upright segments to one another,

- inserting the reinforcement upright into a perforation in the ground,

- consolidating the reinforcement upright and the perforation in the ground by means of a consolidation mixture, by means of casting or injection,

B) connecting the foundation with micropiles to the building by:

- connecting an upper upright segment of the reinforcement upright to a supporting part of the building,

C) seismically isolating the building from the ground by:

- connecting a seismic isolation device between adjacent ends of two of said upright segments after the consolidation by means of the consolidation mixture, in which said seismic isolation device is shear deformable in a direction transverse to the longitudinal axis of the reinforcement upright and is positioned at a distance below an area for the connection of the upper upright segment to the supporting part.

[0028]By virtue of the interposition of the seismic isolation device between two upright segments of the reinforcement upright of the micropile, the micropile thus configured may serve as antiseismic foundation and may be employed to seismically isolate already existing buildings, thus taking advantage of the ease and versatility of execution of the micropile foundations.

[0029]Moreover, again by virtue of the interposition of the seismic isolation device between two upright segments of the reinforcement upright of the micropile, damage to the micropile in case of horizontal stresses during earthquakes is effectively obviated without the need to increase the resistance to shear stresses of the individual upright segments. r00301Description of the drawings

[0031 ]ln order to better understand the invention and appreciate the advantages thereof, a description is provided below of certain non-limiting exemplary embodiments, with reference to the drawings, in which:

- Figure 1 is an exploded view of a foundation system according to an embodiment,

- Figures 2 and 3 are side and sectional views of a guiding and anchoring tube of the foundation system according to an embodiment,

- Figure 4 is a perspective view of a portion of the foundation system, assembled and installed, according to an embodiment,

- Figure 5 is a side view of the foundation system in deformed shear configuration under seismic stress,

- Figures 6 and 7 are sectional and perspective views of a seismic isolation device of the foundation system according to two embodiments,

- Figure 8 is a side view of the foundation system according to an embodiment,

- Figure 9 is a top view of the foundation system in Figure 8,

- Figure 10 is a sectional view according to the section plane X-X in Figure 9,

- Figure 11 is a perspective view of a portion of a seismic isolation device according to an embodiment,

- Figure 12 is a vertical sectional view of the seismic isolation device in Figure 11 ,

- Figure 13 is a side view of a portion of a seismic isolation device according to a further embodiment,

- Figure 14 is a sectional view according to the section plane XIV-XIV in Figure 13,

- Figure 15 is a vertical sectional view of the seismic isolation device in Figure 14,

- Figure 16 is a partial perspective view of a seismic isolation device according to a further embodiment,

- Figure 17 is a vertical sectional view of the seismic isolation device in Figure 16,

- Figure 18 is a horizontal sectional view of the seismic isolation device in Figure 16,

- Figures 19 to 25 show steps of a foundation method according to an embodiment,

- Figures 26 and 27 are three-dimensional views of the steps of the method in Figures 21 and 24.

Detailed description of embodiments

[0032]With reference to the drawings, a foundation system 1 with seismic isolation for buildings 2 comprises:

A) a (preferably metal) reinforcement upright 3 adapted to be inserted into a perforation 4 in ground 5 for the construction of a foundation with micropiles, said reinforcement upright defining a longitudinal axis 6 and comprising:

- a plurality of upright segments 7 each having two opposite ends 8, 8' each forming an upright connection portion 9, 9' which is connectable to a corresponding upright connection portion 9', 9 of an adjacent upright segment 7,

B) a seismic isolation device 10 defining a central axis 11 and comprising:

- a lower support body 12 and an upper support body 13,

- an isolating body 14 which is shear deformable in a direction transverse or perpendicular to the central axis 11 , said isolating body 14 being fastened to and interposed between the lower support body 12 and the upper support body 13 so as to allow a relative movement between the upper support body 13 and the lower support body 12 in the direction transverse to the central axis 11 , in which the lower support body 12 and the upper support body 13 each form an isolator connection portion 15, 15' which is connectable to the upright connection portion 9, 9', for a connection of the seismic isolation device 10 between the adjacent segment ends 8 of two of said upright segments 7 with the central axis 11 and the longitudinal axis 6 being parallel or concentric.

[0033]By virtue of the interposition of the seismic isolation device 10 between two upright segments 7 of the reinforcement upright 3 of the micropile, damage to the micropile in case of horizontal stresses during earthquakes is effectively obviated without the need to increase the resistance to shear stresses of the individual upright segments 7.

[0034]Moreover, again by virtue of the interposition of the seismic isolation device 10 between two upright segments 7 of the reinforcement upright 3 of the micropile, the micropile thus configured may serve as antiseismic foundation and may be employed to seismically isolate structures, in particular existing buildings 2, thus taking advantage of the ease and versatility of execution of the micropile foundations.

[0035]According to one embodiment (Figure 1), the upright segments 7 have a tubular, preferably cylindrical, shape, possibly with a continuous wall or cage wall or intertwined reinforcement bars - wall, with straight longitudinal extension along the longitudinal axis 6, preferably with a constant diameter, in the range from 90 mm to 300 mm, preferably with a segment length in the range from 0.5 m to 2 m.

[0036]Alternatively to the generally tubular shape, the upright segments 7 may be elongated elements with solid or non-tubular lattice cross section.

[0037]The upright segments 7 preferably are made of steel or other metal or alternatively, made of fiber-reinforced polymeric composite material or of reinforced concrete, e.g. fiber- reinforced concrete.

[0038]According to embodiments (Figures 1 , 10), the upright connection portions 9, 9' may be threaded for a mutual connection thereof by screwing. Alternatively or additionally, the upright connection portions 9, 9' may be configured for a mutual insertion of the male-female type, so as to create a connection resistant to bending and shear. Advantageously, the upright connection portions 9, 9' comprise externally threaded male tubular portions and corresponding internally threaded female tubular portions which can be screwed to the male tubular portions. According to a preferred embodiment, each upright segment 7 forms a first externally threaded male upright connection portion 9 at a first segment end 8 thereof and a second internally threaded female upright connection portion 9' at a second segment end 8' thereof.

[0039]Additionally or alternatively (in particular, when the upright segments 7 are made of reinforced concrete or fiber reinforced concrete or of composite material), the mutual connection of the upright connection portions 9, 9' thereof may comprise gluing by means of polymeric resin.

[0040]According to embodiments (Figures 1 , 10), the isolator connection portions 15, 15' may be threaded for a connection thereof with the corresponding upright connection portions 9, 9', by screwing. Alternatively or additionally, the isolator connection portions 15, 15' may be configured for a mutual insertion with the corresponding upright connection portions 9, 9' of the male-female type, so as to create a connection resistant to bending and shear. Advantageously, the isolator connection portions 15, 15' comprise externally threaded male tubular portions and internally threaded female tubular portions which may be screwed with the female upright connection portions 9' and the male upright connection portions 9, respectively, of the upright segments 7. According to a preferred embodiment, each seismic isolation device 10 forms a first externally threaded male isolator connection portion 15 at one of the lower 12 and upper 13 support bodies and a second internally threaded female isolator connection portion 15' at the other of the lower 12 and upper 13 support bodies.

[0041 ]The lower 12 and upper 13 support bodies form a steel plate 16 transversely oriented (preferably orthogonal) to the central axis 11 and having higher stiffness than the stiffness of the isolating body 14 so as to ensure the most uniform transmission of forces as possible between the seismic isolation device 10 and the upright segments 7 connected thereto (Figures 6, 7, 10, 12, 15, 17). The steel plate 16 may be circular in shape (Figures 1 , 6, 7), for example having identical diameter as the upright segments 7, or polygonal in shape, for example rectangular, square or hexagonal (Figures 11 , 14, 18), in order to facilitate the gripping of the screwing tools and/or to allow the employment of seismic isolators, e.g. rectangular, which are commercially available at reduced costs for conventional seismic isolation uses. The isolator connection portions 15, 15' may be welded on an outer surface of the steel plate 16 of the lower 12 and/or upper 13 support bodies.

[0042] According to one embodiment (Figures 6, 12), the isolating body 14 forms a block in elastomeric material 17 having a high stiffness in the direction of the central axis 11 and a high yielding in the direction transverse (preferably orthogonal) to the central axis 11 . The block in elastomeric material 17 may be reinforced by means of metal sheets 18 placed on planes parallel to one another and orthogonal to the central axis 11 (Figures 12, 15). Additionally, the isolating body 14 may internally delimit a cavity 19 filled with lead (Figures 7, 15), whose cyclical plastic deformation in case of cyclical shear deformation of the isolating body 14 increases the energy dissipation of the relative movement between the two upright segments 7 adjacent to the seismic isolation device 10.

[0043]According to preferred embodiments, the block in elastomeric material 17 is made of material selected from the group consisting of: isoprene, which is a natural rubber, neoprene, which is a synthetic rubber, neoprene with additives (e.g. carbon black; silicon, etc.)·

[0044]According to preferred embodiments, the features of deformability, mechanical resistance, viscose-elastic behavior of the elastomeric material of the block in elastomeric material 17 (as well as also the possible metal reinforcement material) are selected from the following ranges:

- dynamic tangential elastic modulus (G _dm ) in the range 0.4 MPa - 1 .4 MPa,

- longitudinal modulus of elasticity (E) in the range 1500 - 3000 Mpa,

- shear deformation capacity greater than 100%,

- relative damping in the range 2% - 4% (Low Damping Rubber Bearing), or

- relative damping in the range 10% - 20% (High Damping Rubber Bearing), or

- relative damping in the range 15% - 35% (Lead Rubber Bearing) in the presence of a lead core.

[0045]According to a further embodiment, the isolating body 14 forms one or more flat or curved sliding interfaces, with sliding friction (e.g. steel-Teflon), with or without lubrication (Figure 17), or one or more rolling bodies interposed between the lower support body 12 and the upper support body 13 (not shown in the drawings).

[0046]According to a further embodiment, the foundation system 1 may comprise, for each reinforcement upright 3, a guiding and anchoring tube 20 (Figures 2, 3, 4) having such a shape and size as to be slidably insertable on the reinforcement upright 3, i.e. on the upright segments 7, to position and guide the reinforcement upright 3 during the insertion into ground 5 thereof. [0047]The guiding and anchoring tube 20 is also intended and prepared to be connected to building 2, for example incorporated in a supporting part 21 (e.g. a reinforced concrete foundation) of building 2, and to be rigidly fastened to the reinforcement upright 3 to create a rigid connection between an upper portion 21 (head portion) of the reinforcement upright 3 and building 2.

[0048]The rigid fastening of the reinforcement upright 3 to the guiding and anchoring tube 20 may occur by welding and/or bolting and/or pins. In order to improve the transmission of forces between building 2 (the supporting part 21 in particular) and the guiding and anchoring tube 20, the guiding and anchoring tube 20 may form one or more protrusions or ribs 22, e.g. a plurality of annular ribs (Figure 4), on an outer surface thereof.

[0049]ln order to facilitate possible vertical preloading operations of the reinforcement upright 3 and/or micropile 26 obtained following the injection and solidification of a consolidation mixture through the reinforcement upright 3, the guiding and anchoring tube 20 advantageously forms one or more coupling seats, e.g. fins, for the connection of a preloading jack to the guiding and anchoring tube 20.

[0050]The guiding and anchoring tube 20 may also form holes 23 (Figures 3, 4) for receiving locking pins or bolts for locking the relative position between the guiding tube 20 and the head of the reinforcement upright 3 following the preloading.

[0051 ]For the injection of the consolidation mixture, for example cement or resin, into the reinforcement upright 3, the foundation system 1 further comprises an injection duct 24 extending along and into the reinforcement upright 3 (during the injection), and which is connectable to a pressure injection pump 25 (Figure 23).

[0052]ln the installed foundation system 1 , the seismic isolation device 10 forms a localized area of structural discontinuity of the reinforcement upright 3 and of the corresponding micropile 26 below the guiding and anchoring tube 20 and at a distance from building 2, in particular from the supporting part 21 (for example, a reinforced concrete foundation), which allows seismically isolating the building 2 from ground 5 by virtue of the possibility of shear deformation of the seismic isolation device 10 shown in Figure 5.

[0053]The invention also relates to a foundation method with seismic isolation for a building 2, comprising the steps of:

A) constructing a foundation with micropiles 26 by:

- assembling a reinforcement upright 3 defining a longitudinal axis 6 by connecting a plurality of upright segments 7 to one another,

- inserting the reinforcement upright 3 into a perforation 4 in ground 5,

- if required, consolidating the reinforcement upright 3 and the perforation 4 in ground 5 by means of a consolidation mixture, by means of casting or injection,

B) connecting the foundation with micropiles 26 to building 2 by:

- connecting an upper upright segment 7 of the reinforcement upright 3 to a supporting part 21 of building 2,

C) seismically isolating building 2 from ground 5 by:

- connecting a seismic isolation device 10 between adjacent segment ends 8, 8' of two of said upright segments 7, in which said seismic isolation device 10 is shear deformable in a direction transverse to the longitudinal axis 6 of the reinforcement upright 3 and is positioned below an area for the connection of the upright segment 7 to the supporting part 21 .

[0054]According to embodiments, the supporting part 21 may be a part of foundation, for example in reinforced concrete or in steel, or a support structure, for example in steel or in reinforced concrete, arranged above the level of the ground, for example at half the height of the first floor of a building or at a height in the range from 0 cm to 500 cm from the level of the ground.

[0055]According to an embodiment, the step of seismically isolating building 2 from ground 5 comprises making a vertical interspace 27 between building 2 and ground 5 to allow relative horizontal movements between building 2 and ground 5.

[0056]According to an embodiment, the step of connecting the reinforcement upright 3 to the supporting part 21 comprises incorporating the guiding and anchoring tube 20 in the support part 21 and fastening, by means of insertion and welding and/or bolting and/or pins, the upper upright segment 7 in the guiding and anchoring tube 20.

[0057]The insertion of the reinforcement upright 3 into ground 5 may occur by lowering the reinforcement upright 3 into a perforation 4 made previously in ground 5 or by means of self drilling driving the reinforcement upright 3 into ground 5, in which making perforation 4 and inserting the reinforcement upright 3 into perforation 4 occur simultaneously.

[0058]According to a further embodiment, the insertion and assembly of the reinforcement upright 3 occurs by alternating the steps of inserting the only partially assembled reinforcement upright 3 with the steps of assembling further upright segments 7 at an upper end of the partially assembled reinforcement upright 3. This allows making micropiles 26 having increased depth and working in confined spaces, for example in the presence of protrusions (balconies, eaves) or overlying slabs of the same building 2 or of buildings adjacent to the construction site.

[0059]According to a further embodiment, the steps of inserting the reinforcement upright 3 and of consolidating by means of the consolidation mixture (when provided) are carried out before assembling the seismic isolation device 10 in the reinforcement upright 3. This allows a free access inside the reinforcement upright 3 and an easier application of the equipment and mechanical stresses required to drive the reinforcement upright 3 into ground 5. [0060]Advantageously, following the completion of the insertion of the reinforcement upright 3 and (when provided) the consolidation by means of the consolidation solution, the upper upright segment 7 is disassembled from the underlying part of the reinforcement upright 3, i.e. micropile 26, and the seismic isolation device 10 is inserted and fastened between the upper upright segment 7 and the underlying part of the reinforcement upright 3. [0061]Particularly advantageously, building 2 is pre-existing to the construction of the foundation with micropiles 26 and the supporting part 21 is made and connected to the pre existing building 2 before inserting the reinforcement upright 3 into ground 5.

[0062]Further advantageously, the supporting part 21 is connected to the pre-existing building

2 by making holes 31 in load-bearing elements 28 of building 2 and constructing the supporting part 21 in reinforced concrete and extending into the holes 31 (Figures 21 , 22).

[0063]lndeed, the foundation method according to the invention is particularly advantageous for an adaptation of existing buildings to the same seismic stresses provided for designing newly constructed buildings.

[0064]According to a preferred embodiment (Figures 19-27), starting from an existing state of building 2 with vertical load-bearing elements 28 at the foundation level, or above, with original backfilling 29 (Figure 19), the following steps are performed:

[0065]- making an excavation 30 with planned shape and size at the load-bearing elements 28 (Figure 20),

[0066]- making holes 31 in the load-bearing element 28 (Figure 21) with possible arrangement of a lower separating layer 32, for example a polymeric film, in a lower intrados area of each hole 31 ,

[0067]- constructing the supporting part 21 in reinforced concrete at the load-bearing element 28 and with a penetration of the supporting part 21 into the holes 31 for a load-bearing connection of the supporting part 21 to the load-bearing element 28 of building 2 (Figure 22). The supporting part 21 may be configured as a beam or plate structure. By virtue of the lower separators 32 previously positioned in the lower intrados area of the holes 31 , the supporting part 21 is disconnected from a possible portion underlying the load-bearing element 28, for example by an existing supporting part of building 2.

[0068]lt is advantageous to incorporate the guiding and anchoring tube 20 in the supporting part 21 (Figure 22) during the construction of the supporting part 21 in reinforced concrete. [0069]- Inserting the reinforcement upright 3 from the top downwards, through the guiding and anchoring tube 20 (which may act as positioning reference and guide) incorporated in or connected to the supporting part 21 , and inserting the reinforcement upright 3 into ground 5, in which the reinforcement upright 3 is still without the seismic isolation device 10 (Figure 23), [0070]- when provided, injecting consolidation mixture through the reinforcement upright 3 to anchor the reinforcement upright 3 to ground 5 which accommodates the reinforcement upright

3 to make the micropile 26 (Figure 23),

[0071]- following the completion of the insertion of the reinforcement upright 3 and the consolidation by means of the consolidation mixture, disassembling the upper upright segment 7 from an underlying part of the reinforcement upright 3, i.e. micropile 26, and fastening the seismic isolation device 10 between the upper upright segment 7 and the underlying part of the reinforcement upright 3 (Figure 24),

[0072]- preloading from above the reinforcement upright 3 (and the entire micropile 26), including the seismic isolation device 10 integrated therein, for example by means of a jack 33 which engages the guiding and anchoring tube 20 and the upper upright segment 7 and which pushes the reinforcement upright 3 downwards with respect to the guiding and anchoring tube 20, and fastening the upper upright segment 7, for example by means of welding, bolts and/or pins, to the guiding and anchoring tube 20 (Figure 24),

[0073]- making the vertical interspace 27 between building 2 and ground 5 to allow relative horizontal movements between building 2 and ground 5 (Figure 25),

[0074]- horizontally cutting 35 the load-bearing element 28 below the connection of the load- bearing element 28 to the supporting part 21 , to disconnect building 2 from an original part thereof underlying the load-bearing element 28 (Figure 25),

[0075]- constructing an inspection pit 34 at the position of the seismic isolation device 20 in the reinforcement upright 3 (Figure 25) and/or making vertical holes in the supporting part 21 for the passage of an inspection camera to view the seismic isolation device 10,

[0076]- optionally, filling excavation 30 with soil around the inspection pit 34 (Figure 25). [0077]The sequence of steps of the method described was indicated by way of non-limiting, but particularly advantageous, example. According to alternative embodiments, one or more steps may be omitted or carried out in different order with respect to the one described. [0078]Those skilled in the art will appreciate that the foundation method according to the invention is applicable in a highly versatile manner both to newly constructed buildings and for the seismic rehabilitation of existing buildings, as well as under conditions of confined spaces, such as for example in urban and densely built-up environments.

List of references:

1 foundation system

2 building

3 reinforcement upright

4 perforation

5 ground

6 longitudinal axis

7 upright segments

8 first segment end (male) ' second segment end (female) male upright connection portion ' female upright connection portions 0 seismic isolation device 1 central axis 2 lower support body 3 upper support body 4 isolating body 5 first isolator connection portion (male) 5' second isolator connection portion (female) 6 steel plate 7 block in elastomeric material 8 metal sheets 9 cavity filled with lead 0 guiding and anchoring tube 1 supporting part 2 guiding tube ribs 3 guiding tube holes 4 injection duct 5 injection pump 6 micropile 7 vertical interspace 8 load-bearing elements 9 original backfilling 0 excavation 1 holes in the load-bearing elements 2 lower separating layer 3 jack 4 inspection pit 5 horizontal cutting