METHOD OF RAISING A BUILDING STRUCTURE, IN PARTICULAR A BUILDING STRUCTURE SUBJECT TO FLOODING

Description

TECHNICAL FIELD

[0001] The present invention relates to a method of raising a building structure.

BACKGROUND ART

[0002] In the building industry, it is often necessary to raise a building structure, e.g. to raise a waterfront or seafront building above high-water or high-tide level. A typical example of this is the city of Venice where the ground floors of buildings are cyclically subject to flooding by high-tide or so-called "high-water" phenomena.

[0003] Alternatively, a building structure may be raised to build a basement when excavation work beneath the building is either impossible or undesirable.

[0004] DE19949562A1 discloses a foundation slab hold and lift equipment comprising tie-rods fixed to top load plate and led through slab hole and powered by hydraulic cylinders in guide pipe to project both sides of slab for the lift.

[0005] US6390734B1 discloses a device and method for leveling and supporting a slab foundation on a column of piling sections.

DISCLOSURE OF INVENTION

[0006] It is an object of the present invention to provide a method of raising a building structure, which is cheap and easy to implement.

[0007] According to the present invention, there is provided a method of raising a building structure as recited in the accompanying claims.

BRIEF DESCRIPTION OF THE DRAWINGS

[0008] A number of non-limiting embodiments of the present invention will be described by way of example with reference to the accompanying drawings, in which:

Figures 1 to 3 show schematic front sections of a building raised using the method according to the present invention;

Figure 4 shows a larger-scale view of a detail in Figure 1;

Figures 5 and 6 show the Figure 4 detail in two different operating configurations;

Figure 7 shows a larger-scale view of an alternative embodiment of the Figure 4 detail;

Figure 8 shows a schematic front section of a further building raised using the method according to the present invention.

BEST MODE FOR CARRYING OUT THE INVENTION

[0009] Number 1 in Figure 1 indicates as a whole a building resting on the ground 2 on a foundation structure 3, and which must be raised with respect to ground 2. More specifically, foundation structure 3 is defined by a reinforced-concrete slab.

[0010] It should be pointed out that, depending on the construction characteristics of building 1, foundation structure 3 may either exist already, or may be formed from an existing foundation structure shortly before the building is raised.

[0011] To begin with, a number of vertical through holes 4 are core drilled through foundation structure 3. Close to each hole 4, at least two threaded bars 5 are then fixed to foundation structure 3 with a top portion of each bar projecting upwards. Preferably, at least two bars 5 are positioned vertically adjacent to each hole 4 and symmetrically with respect to the axis of hole 4 (alternatively, metal cables may be used instead of bars 5).

[0012] Once foundation structure 3 is built, a metal pile 6 is inserted through each hole 4, and comprises a substantially constant-section rod 7, and a wider bottom head 8 defining a bottom end of pile 6. Each rod 7 is defined by a cylindrical tube having a through inner conduit 9, and is smaller transversely than relative hole 4 so as to fit relatively easily through hole 4. Each head 8 is defined by a flat, substantially circular plate 10 of substantially the same size transversely as hole 4.

[0013] Each pile 6 may obviously differ from the one shown in the accompanying drawings. For example, each pile 6 may be defined by an "I" girder, as opposed to being tubular and hollow.

[0014] Each hole 4 is preferably lined with a metal guide tube 11, which is fixed to foundation structure 3 by a ring 12 embedded in foundation structure 3, and has a top portion 13 projecting upwards from foundation structure 3. In an alternative embodiment not shown, as opposed to being fixed directly to foundation structure 3, the bottom portion of each bar 5 is connected to top portion 13 of relative guide tube 11.

[0015] In the Figure 7 embodiment, each head 8 is larger transversely than hole 4, is initially separate from rod 7, and, when building foundation structure 3, is laid substantially contacting ground 2 beneath foundation structure 3 and coaxial with hole 4, so that each rod 7 engages relative head 8 to form relative pile 6 when rod 7 is inserted through hole 4. To ensure sufficiently firm mechanical connection of rod 7 and head 8, head 8 is provided with a connecting member 14, which engages rod 7 to fix rod 7 transversely to head 8. More specifically, each connecting member 14 is defined by a cylindrical tubular member projecting axially from plate 10 and sized to engage a bottom portion of inner conduit 9 of rod 7 with relatively little clearance. To lay head 8 in an existing foundation structure 3, foundation structure 3 is core drilled and then partly restored to form a relative hole 4 smaller transversely than head 8. The Figure 4 embodiment is generally preferred when a complete foundation structure 3 already exists before raising the building, and holes 4 are core drilled in foundation structure 3; the Figure 7 embodiment is preferred when foundation structure 3 is partly built to raise the building, and heads 8 can therefore be laid on ground 2 and subsequently covered by foundation structure 3.

[0016] Once a pile 6 is inserted inside each hole 4, each pile 6 is connected to a thrust device 15, which at one end rests on a top end 16 of pile 6, and at the other end is connected to the projecting portions of bars 5. More specifically, each thrust device 15 is defined by a hydraulic jack comprising a body 17, and a rod 18 movable axially with adjustable force with respect to body 17. Body 17 rests on top end 16 of pile 6, and rod 18 is positioned contacting an underside surface of a metal plate 19 fitted through with bars 5 and made axially integral with bars 5 by respective bolts 20 (Figure 5) engaging respective threaded top portions of bars 5.

[0017] In actual use, each thrust device 15 is operated to produce a given force between respective body 17 and respective rod 18, and so statically apply thrust, of the same intensity as the force, between pile 6 and foundation structure 3. More specifically, thrust is transmitted to foundation structure 3 by bars 5, which act as reaction members and maintain a constant distance between plate 19 and foundation structure 3 as rod 18 slides out of body 17.

[0018] A control unit 21 is connected to thrust devices 15 to supply each thrust device 15 with a control signal governing the thrust to be applied. Coritrol unit 21 is also connected to a number of pressure sensors 22, each associated with a thrust device 15 to measure the instantaneous thrust applied by thrust device 15, and is connected to a number of large-base extensometers 23 fitted to the walls and/or columns of building 1 to measure the lift-induced strain on building 1. Using pressure sensors 22, control unit 21 is able to feedback control thrust devices 15 and determine the thrust applied instant by instant by thrust devices 15.

[0019] Set-up of thrust devices 15 as described above results in the situation shown in Figure 1. At this point, control unit 21 (either automatically or under the supervision of an operator) operates each thrust device 15 independently to apply a given thrust between respective pile 6 and foundation structure 3 and raise building 1 with respect to ground 2 (Figure 2). The thrusts applied on one pile 6 normally differ from those applied on the other piles 6, are always less than the design capacity of piles 6, and are calculated instant by instant, depending on how building 1 is to be raised, and on the signals from extensometers 23.

[0020] Depending on the desired lift height, rod 7 of each pile 6 may be a one-piece body, or may be formed by joining a number of tubular segments, which are inserted successively through hole 4 and welded to one another as building 1 is raised with respect to ground 2. In other words, on reaching the end of a first segment of rod 7, thrust device 15 is disconnected from the top end of the first segment to insert a second segment, which is butt welded to the first segment; and thrust device 15 is connected to the top end of the second segment to continue to the lift cycle. In an alternative embodiment, two successive tubular segments of rod 7 are fixed to each other by a connecting piece partly engaging the inner conduits of the two segments.

[0021] As shown in detail in Figure 6, once building 1 is raised, thrust devices 15 are dismantled and inner conduit 9 of each pile 6 is filled with substantially plastic-state cement 24, in particular concrete. Once inner conduit 9 of each pile 6 is filled, pile 6 is fixed axially to foundation structure 3 by fitting (normally welding) to projecting portion 13 of relative guide tube 11 a horizontal metal plate 25 (or an annular flange), which is placed on top of pile 6 to engage top end 16 of pile 6. Preferably, each pile 6 is driven so that relative top end 16 is lower than the top surface 26 of foundation structure 3, projecting portion 13 of relative guide tube 11 is cut, and plate 25 is fixed to the rest of guide tube 11 so as to be substantially coplanar with top surface 26 of foundation structure 3, thus enabling the whole of top surface 26 of foundation structure 3 to be walked on. Once each pile 6 is fixed axially to foundation structure 3, the projecting portions of relative bars 5 are cut.

[0022] In an alternative embodiment not shown, each pile 6 is fixed axially to foundation structure 3 by fitting bars 5 with plate 25, which is placed on top of pile 6 to engage top end 16 of pile 6.

[0023] As shown in Figure 3, once the building is raised, a cavity 27 is formed beneath foundation structure 3 and may be used to build a basement.

[0024] In an alternative embodiment shown in Figure 8, as opposed to resting directly on ground 2, foundation structure 3 rests on a further foundation structure 28 having numerous piles 29 driven into ground 2 beneath a watercourse 30 or a basin 30 (e.g. a lagoon). This solution is typical of a building 1 built on water, wherein piles 29 of further foundation structure 28 are driven into ground 2 beneath, and support building 1 above, the water level of watercourse or basin 30. If foundation structure 3 rests on an existing further foundation structure 28, heads 8 of piles 6 obviously rest on further foundation structure 28, so that, when raising the building, foundation structure 3 and building 1 are therefore raised with respect to further foundation structure 28, as described above.

[0025] In an alternative embodiment not shown in detail, as opposed to resting directly on ground 2, foundation structure 3 rests on numerous piles driven into ground 2. This solution is typical of a building 1 built on water, wherein the piles of the further foundation structure are driven into ground 2 beneath, and support building 1 above, the water level.

[0026] It should be pointed out that, before raising the building as described above, a static analysis of building 1 must be conducted to ensure building 1 is capable of safely withstanding the stresses induced when raising it. If necessary, building 1 may be strengthened before it is raised.

[0027] When raising building 1, the load applied on each pile 6 may cause some of piles 6 to sink into ground 2. This problem can easily be solved by simply increasing the length (as described above) of the sunken piles 6 by the same amount as the sink depth. In an embodiment not shown, to prevent piles 6 from sinking, one or more metal plates may be laid beneath foundation structure 3. This solution is particularly effective when foundation structure 3 rests on a bed of gravel.

[0028] It is normally advisable to dig a trench around building 1 to eliminate the stabilizing effect of the surrounding earth and so make building 1 easier to raise. The trench should be dug by degrees to avoid disturbing the existing equilibrium, and adequate temporary bracing should be provided to prevent cave-in.

[0029] If building 1 is located close to a watercourse, it may be advisable or necessary to construct a dam about foundation structure 3 to prevent water infiltrating into cavity 27 formed beneath foundation structure 3 when raising building 1.

[0030] If building 1 shares one or more walls with adjoining buildings, all the floors connected to the common wall must be detached to raise the floors with respect to the common wall, and must be reconnected to the common wall once the building is raised. Obviously, before being detached from a common wall, the floor must be adequately propped using a temporary metal frame adjacent to, but not contacting, the common wall. This method also applies to exceptionally large buildings (roughly with a base area of over 1000 sq.m) which are divided into a number of parts which are raised separately.

Claims

1. A method of raising a building structure (1), resting on an first foundation structure (28), with respect to the first foundation structure (28); the method comprising the steps of:

forming a second foundation structure (3) on the first foundation structure (28) for supporting the building structure (1) with respect to the first foundation structure (28) and having a number of through holes, (4), and a number of connecting members, each fixed to the second foundation structure (3) close to a respective hole (4) and having at least one portion (13) projecting upwards;

inserting through each hole (4) a pile (6) having a bottom end (8) resting on the first foundation structure (28), and a top end (16) projecting from the hole (4);

fitting to each pile (6) a respective thrust device (15), which rests at one end on the top end (16) of the pile (6) and is secured at the other end to the corresponding connecting member which acts as a reaction member;

statically applying a respective thrust on each pile (6) by means of the respective thrust device (15) to raise the seconde foundation structure (3) together with the building structure (1) with respect to the first foundation structure (28); and

fixing each pile (6) axially to the second foundation structure (3) once raising is competed;

wherein each pile (6) comprises a metal rod (7) of substantially constant section defined by a number of segment, which are inserted successively through the respective hole (4) and joined to one another; and a wider metal bottom head (8);

the method is characterized in comprising the further steps of:

lining, when forming the second foundation structure (3), each hole (4) with a metal guide tube (11), which is fixed to the second foundation structure (3) and has a portion projecting upwards from said second foundation structure (3); and

using each guide tube (11) as connecting member acting as a reaction member and secured to the respective thrust device (15).

2. A method as claimed in Claim 1, wherein the first foundation structure (28) comprises a large number of piles (29) driven into the ground (2).

3. A method as claimed in Claim 2, wherein the first foundation structure (28) comprises a large number of piles (29) driven into the ground (2) beneath a watercourse (30) or a basin (30).

4. A method as claimed in one of Claims 1 to 3, wherein raising is controlled by a control unit (21), which controls the thrust devices (15) and is connected to a number of extensometers (23) fixed to the building structure (1).

5. A method as claimed in Claim 4, wherein the control unit (21) is connected to sensors (22) mounted on the thrust devices (15) to determine, instant by instant, the intensity of the thrusts exerted by the thrust devices (15).

6. A method as claimed in Claim 5, wherein the control unit (21) feedback controls the thrust devices (15).

7. A method as claimed in one of Claims 1 to 6, wherein each head (8) is sized transversely to permit insertion of the head (8) through the respective hole (4).

8. A method as claimed in Claim 7, wherein each head (8) is larger transversely than the respective hole (4), is initially separate from the rod (7), and, when forming the second foundation structure (3), is positioned substantially contacting the first foundation structure (28) beneath the second foundation structure (3) and substantially coaxial with the hole (4); and the rod (7) engages the head (8) when the rod (7) is inserted through the hole (4).

9. A method as claimed in Claim 8, wherein the head (8) comprises a joining member (14), which engages the rod (7) to fix the rod (7) transversely to the head (8).

10. A method as claimed in Claim 9, wherein the rod (7) is defined by a cylindrical tube having an inner conduit (9), a bottom portion of which is engaged by the joining member (14).

11. A method as claimed in one of Claims 1 to 10, wherein each rod (7) is defined by a cylindrical tube having an inner conduit (9); and, once raising is completed, a substantially plastic-state cement material (24) is fed into the inner conduit (9).

12. A method as claimed in Claim 11, wherein said cement material (24) is defined by concrete.

13. A method as claimed in one of Claims 1 to 12, wherein, once raising is completed, each pile (6) is fixed axially to the second foundation structure (3) by securing to the connecting member a horizontal metal plate (25), which is placed, on top of the pile (6) to engage a top end (16) of the pile (6).

14. A method as claimed in one of Claims 1 to 13, wherein at least one metal plate is placed beneath the second foundation structure (3), rests on the first foundation structure (28), and on which the bottom ends (8) of the piles (6) rest.

15. A method as claimed in one of Claims 1 to 14, wherein:

a control unit (21) is connected to the thrust devices (15) to supply each thrust device (15) with a control signal governing the thrust to be applied;

the control unit (21) is connected to a number of pressure sensors (22), each associated with a thrust device (15) to measure the instantaneous thrust applied by thrust device (15), and is connected to a number of large-base extensometers (23) fitted to the walls and/or columns of the building structure (1) to measure the lift-induced strain on the building structure (1); and

using the pressure sensors (22), the control unit (21) is able to feedback control the thrust devices (15) and determine the thrust applied instant by instant by the thrust devices (15).

16. A method as claimed in claim 15, wherein the control unit (21) operates each thrust device (15) independently to apply a given thrust between the respective pile (6) and the second foundation structure (3) and raise the building structure (1) with respect to the first foundation structure (28).

17. A method as claimed in claim 16, wherein the thrusts applied on one pile (6) normally differ from those applied on the other piles (6), are always less than the design capacity of piles (6), and are calculated instant by instant, depending on how the building structure (1) is to be raised, and on the signals from the extensometers (23).

Ansprüche

1. Verfahren zum Anheben einer Gebäudestruktur (1), die auf einer ersten Fundamentstruktur (28) ruht, in Bezug auf die erste Fundamentstruktur (28); wobei das Verfahren die folgenden Schritte umfasst:

Ausbilden einer zweiten Fundamentstruktur (3) auf der ersten Fundamentstruktur (28), um die Gebäudestruktur (1) in Bezug auf die erste Fundamentstruktur (28) zu halten, und die eine Anzahl von Durchgangslöchern (4) und eine Anzahl von Verbindungselementen hat, die jeweils an der zweiten Fundamentstruktur (3) nahe an einem jeweiligen Loch (4) befestigt sind und wenigstens einen Abschnitt (13) hat, der aufwärts vorsteht;

Einsetzen eines Pfeilers (6) mit einem unteren Ende (6), das auf der ersten Fundamentstruktur (28) ruht, und einem oberen Ende (16), das aus dem Loch (4) vorsteht, durch jedes Loch (4);

Montieren einer jeweiligen Axialschubvorrichtung (15) an jedem Pfeiler (6), die an einem Ende auf dem oberen Ende (16) des Pfeilers (6) ruht und an dem anderen Ende an dem entsprechenden Verbindungselement befestigt ist, das als ein Reaktionselement wirkt,

statisches Anwenden eines jeweiligen Axialschubs auf jeden Pfeiler (6) mit Hilfe der jeweiligen Axialschubvorrichtung (15), um die zweite Fundamentstruktur (3) zusammen mit der Gebäudestruktur (1) in Bezug auf die erste Fundamentstruktur (28) anzuheben; und

axiales Befestigen jedes Pfeilers (6) an der zweiten Fundamentstruktur (3), wenn das Anheben einmal abgeschlossen ist;

wobei jeder Pfeiler (6) eine Metallstange (7) mit im Wesentlichen konstantem Querschnitt, der durch eine Anzahl von Segmenten definiert ist, die nacheinander durch das jeweilige Loch (4) eingesetzt und miteinander verbunden sind; und einen breiteren unteren Metallkopf (8) umfasst;

wobei das Verfahren dadurch gekennzeichnet ist, dass es die folgenden weiteren Schritte umfasst:

wenn die zweite Fundamentstruktur (3) ausgebildet wird, Auskleiden jedes Lochs (4) mit einem Metallführungsrohr (11), das an der zweiten Fundamentstruktur (3) befestigt ist und einen Vorsprung hat, der von der zweiten Fundamentstruktur (3) aufwärts vorsteht; und

Verwenden jedes Führungsrohrs (11) als ein Verbindungselement, das als ein Reaktionselement wirkt und an der jeweiligen Axialschubvorrichtung (15) befestigt ist.

2. Verfahren nach Anspruch 1, wobei die erste Fundamentstruktur (28) eine große Anzahl von Pfeilern (29) umfasst, die in den Boden (2) angetrieben werden.

3. Verfahren nach Anspruch 2, wobei die erste Fundamentstruktur (28) eine große Anzahl von Pfeilern (29) umfasst, die in den Boden (2) unterhalb eines Wasserlaufs (30) oder eines Beckens (30) angetrieben werden.

4. Verfahren nach einem der Ansprüche 1 bis 3, wobei das Anheben von einer Steuereinheit (21) gesteuert wird, die die Axialschubvorrichtungen (15) steuert und mit einer Anzahl von Dehnungsmessern (23) verbunden ist, die an der Gebäudestruktur (1) befestigt sind.

5. Verfahren nach Anspruch 4, wobei die Steuereinheit (21) mit Sensoren (22) verbunden ist, die auf den Axialschubvorrichtungen (15) montiert sind, um momentweise die Intensität der Axialschübe, die von den Axialschubvorrichtung (15) ausgeübt werden, zu bestimmen.

6. Verfahren nach Anspruch 5, wobei die Steuereinheit (21) die Axialschubvorrichtungen (15) per Rückkopplung steuert.

7. Verfahren nach einem der Ansprüche 1 bis 6, wobei jeder Kopf (8) quer dimensioniert ist, um das Einsetzen des Kopfs (8) durch das jeweilige Loch zuzulassen.

8. Verfahren nach Anspruch 7, wobei jeder Kopf (8) quer größer als das jeweilige Loch (4) ist, anfänglich von der Stange (7) getrennt ist und, wenn die zweite Fundamentstruktur (3) ausgebildet wird, im Wesentlichen in Kontakt mit der ersten Fundamentstruktur (28) unterhalb der zweiten Fundamentstruktur (3) und im Wesentlichen koaxial mit dem Loch (4) positioniert ist; und die Stange (7) in den Kopf (8) eingreift, wenn die Stange (7) durch das Loch (4) eingesetzt ist.

9. Verfahren nach Anspruch 8, wobei der Kopf (8) ein Verbindungselement (14) umfasst, das in die Stange (7) eingreift, um die Stange (7) quer zu dem Kopf (8) zu befestigen.

10. Verfahren nach Anspruch 9, wobei die Stange (7) durch ein zylindrisches Rohr mit einem Innenkanal (9) definiert ist, dessen Bodenabschnitt mit dem Verbindungselement (14) in Eingriff ist.

11. Verfahren nach einem der Ansprüche 1 bis 10, wobei jede Stange (7) durch ein zylindrisches Rohr mit einem Innenkanal (9) definiert ist und, wenn das Anheben einmal abgeschlossen ist, im Wesentlichen Zementmaterial (24) in plastischem Zustand in den Innenkanal (9) eingespeist wird.

12. Verfahren nach Anspruch 11, wobei das Zementmaterial (24) durch Beton definiert wird.

13. Verfahren nach einem der Ansprüche 1 bis 12, wobei, wenn das Anheben einmal abgeschlossen ist, jeder Pfeiler (6) axial an der zweiten Fundamentstruktur (3) befestigt wird, indem eine horizontale Metallplatte (25) an dem Verbindungselement befestigt wird, die oben auf dem Pfeiler (6) angeordnet ist, um in ein oberes Ende (16) des Pfeilers (6) einzugreifen.

14. Verfahren nach einem der Ansprüche 1 bis 13, wobei wenigstens eine Metallplatte unterhalb der zweiten Fundamentstruktur (3) angeordnet ist, auf der ersten Fundamentstruktur (28) ruht und die unteren Enden (8) der Pfeiler (6) auf ihr ruhen.

15. Verfahren nach einem der Ansprüche 1 bis 14, wobei
eine Steuereinheit (21) mit den Axialschubvorrichtungen (15) verbunden ist, um jede Axialschubvorrichtung (15) mit einem Steuersignal zu versorgen, das den Axialschub, der angewendet werden soll, regelt;
die Steuereinheit (21) mit einer Anzahl von Drucksensoren (22) verbunden ist, von jeden jeder zu einer Axialschubvorrichtung (15) gehört, um den momentanen Axialschub, der von der Axialschubvorrichtung (15) angewendet wird, zu messen, und mit einer Anzahl von Dehnungsmessern (23) mit großer Basis verbunden ist, die an die Wände und/oder Säulen der Gebäudestruktur (1) montiert sind, um die durch das Anheben induzierte Spannung auf der Gebäudestruktur (1) zu messen; und
die Steuereinheit unter Verwendung der Drucksensoren (22) fähig ist, die Axialschubvorrichtungen (15) durch Rückkopplung zu steuern und den durch die Axialschubvorrichtungen (15) angewendeten Axialdruck momentweise zu bestimmen.

16. Verfahren nach Anspruch 15, wobei die Steuereinheit (21) jede Axialschubvorrichtung (15) unabhängig betreibt, um einen gegebenen Axialschub zwischen dem jeweiligen Pfeiler (6) und der zweiten Fundamentstruktur (3) anzuwenden und die Gebäudestruktur (1) in Bezug auf die erste Fundamentstruktur (28) anzuheben.

17. Verfahren nach Anspruch 16, wobei die auf einen Pfeiler (6) angewendeten Axialschübe sich normalerweise von denen die auf die anderen Pfeiler (6) angewendet werden, unterscheiden, immer kleiner als die konstruktive Kapazität der Pfeiler (6) sind und momentweise abhängig davon, wie die Gebäudestruktur (1) angehoben werden soll, und von den Signalen von den Dehnungsmessern (23) berechnet werden.

Revendications

1. Procédé de surélévation d'une structure de bâtiment (1), reposant sur une première structure de fondation (28), par rapport à la première structure de fondation (28) ; le procédé comprenant les étapes de :

formation d'une seconde structure de fondation (3) sur la première structure de fondation (28) permettant de supporter la structure de bâtiment (1) par rapport à la première structure de fondation (28) et ayant un certain nombre de trous traversants (4), et un certain nombre d'organes de liaison, chacun fixé à la seconde structure de fondation (3) près d'un trou (4) respectif et ayant au moins une portion (13) faisant saillie vers le haut ;

insertion à travers chaque trou (4) d'un pieu (6) ayant une extrémité basse (8) reposant sur la première structure de fondation (28), et une extrémité haute (16) faisant saillie depuis le trou (4) ;

installation sur chaque pieu (6) d'un dispositif de poussée (15) respectif, qui repose au niveau d'une extrémité sur l'extrémité haute (16) du pieu (6) et est solidarisé au niveau de l'autre extrémité à l'organe de liaison correspondant qui agit comme un organe de réaction ;

application statique d'une poussée respective sur chaque pieu (6) au moyen du dispositif de poussée (15) respectif pour surélever la seconde structure de fondation (3) conjointement avec la structure de bâtiment (1) par rapport à la première structure de fondation (28) ; et

fixation de chaque pieu (6) de façon axiale sur la seconde structure de fondation (3) une fois que la surélévation est achevée ;

dans lequel chaque pieu (6) comprend une tige en métal (7) de section sensiblement constante définie par un certain nombre de segments, qui sont insérés successivement à travers le trou (4) respectif et joints les uns aux autres ; et une tête basse plus large en métal (8) ;

le procédé est caractérisé en ce qu'il comprend les étapes supplémentaires de :

revêtement, lors de la formation de la seconde structure de fondation (3), de chaque trou (4) avec un tube-guide en métal (11), qui est fixé à la seconde structure de fondation (3) et a une portion faisant saillie vers le haut depuis ladite seconde structure de fondation (3) ; et

utilisation de chaque tube-guide (11) comme organe de liaison servant d'organe de réaction et solidarisé au dispositif de poussée (15) respectif.

2. Procédé selon la revendication 1, dans lequel la première structure de fondation (28) comprend un grand nombre de pieux (29) enfoncés dans le sol (2).

3. Procédé selon la revendication 2, dans lequel la première structure de fondation (28) comprend un grand nombre de pieux (29) enfoncés dans le sol (2) en dessous d'un cours d'eau (30) ou d'un bassin (30).

4. Procédé selon l'une des revendications 1 à 3, dans lequel la surélévation est commandée par une unité de commande (21), qui commande les dispositifs de poussée (15) et est reliée à un certain nombre d'extensomètres (23) fixés à la structure de bâtiment (1).

5. Procédé selon la revendication 4, dans lequel l'unité de commande (21) est reliée à des capteurs (22) montés sur les dispositifs de poussée (15) pour déterminer, instant par instant, l'intensité des poussées exercées par les dispositifs de poussée (15).

6. Procédé selon la revendication 5, dans lequel l'unité de commande (21) commande par rétroaction les dispositifs de poussée (15).

7. Procédé selon l'une des revendications 1 à 6, dans lequel chaque tête (8) est dimensionnée transversalement pour permettre l'insertion de la tête (8) à travers le trou (4) respectif.

8. Procédé selon la revendication 7, dans lequel chaque tête (8) est plus grande transversalement que le trou (4) respectif, est initialement séparée de la tige (7) et, lors de la formation de la seconde structure de fondation (3), est positionnée sensiblement en contact avec la première structure de fondation (28) en dessous de la seconde structure de fondation (3) et sensiblement coaxiale avec le trou (4) ; et la tige (7) enclenche la tête (8) lorsque la tige (7) est insérée à travers le trou (4).

9. Procédé selon la revendication 8, dans lequel la tête (8) comprend un organe de jonction (14), qui enclenche la tige (7) pour fixer la tige (7) transversalement avec la tête (8).

10. Procédé selon la revendication 9, dans lequel la tige (7) est définie par un tube cylindrique ayant un conduit interne (9), dont une portion basse est enclenchée par l'organe de jonction (14).

11. Procédé selon l'une des revendications 1 à 10, dans lequel chaque tige (7) est définie par un tube cylindrique ayant un conduit interne ; et une fois que la surélévation est achevée, un matériau de ciment sensiblement à l'état plastique (24) est introduit dans le conduit interne (9).

12. Procédé selon la revendication 11, dans lequel ledit matériau de ciment (24) est défini par du béton.

13. Procédé selon l'une des revendications 1 à 12, dans lequel, une fois que la surélévation est achevée, chaque pieu (6) est fixé axialement à la seconde structure de fondation (3) en solidarisant à l'organe de liaison une plaque de métal horizontale (25), qui est placée par-dessus le pieu (6) pour enclencher une extrémité haute (16) du pieu (6).

14. Procédé selon l'une des revendications 1 à 13, dans lequel au moins une plaque de métal est placée en dessous de la seconde structure de fondation (3), repose sur la première structure de fondation (28), et sur laquelle les extrémités basses (8) des pieux (6) reposent.

15. Procédé selon l'une des revendications 1 à 14, dans lequel :

une unité de commande (21) est reliée aux dispositifs de poussée (15) pour fournir à chaque dispositif de poussée (15) un signal de commande gouvernant la poussée à appliquer ;

l'unité de commande (21) est reliée à un certain nombre de capteurs de pression (22), chacun associé à un dispositif de poussée (15) pour mesurer la poussée instantanée appliquée par le dispositif de poussée (15), et est reliée à un certain nombre d'extensomètres à grande base (23) installés sur les parois et/ou les colonnes de la structure de bâtiment (1) pour mesurer l'effort induit par soulèvement sur la structure de bâtiment (1) ; et

en utilisant les capteurs de pression (22), l'unité de commande (21) est capable de commander par rétroaction les dispositifs de poussée (15) et de déterminer la poussée appliquée instant par instant par les dispositifs de poussée (15).

16. Procédé selon la revendication 15, dans lequel l'unité de commande (21) actionne chaque dispositif de poussée (15) indépendamment pour appliquer une poussée donnée entre le pieu (6) respectif et la seconde structure de fondation (3) et surélever la structure de bâtiment (1) par rapport à la première structure de fondation (28).

17. Procédé selon la revendication 16, dans lequel les poussées appliquées sur un pieu (6) diffèrent normalement de celles appliquées sur les autres pieux (6), sont toujours inférieures à la capacité nominale des pieux (6), et sont calculées instant par instant, selon comment la structure de bâtiment (1) doit être surélevée, et selon les signaux provenant des extensomètres (23).

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