CN111836932A - Seismic device - Google Patents

Abstract

An anti-seismic device (1) for seismic isolation of a structure (2) with respect to a ground (3) is provided, comprising: a first support (4) defining a first support plane (4a) integrally connectable to the upper portion and comprising at least two first hinges (40) defining a first constant reciprocal distance (d'); a second support (5) defining a second support plane (5a) and comprising at least two second hinges (50) defining a second constant reciprocal distance (d "); a third support (6) defining a third support plane (6a) integrally connectable to the lower part and comprising at least two third hinges (60) defining a third constant reciprocal distance (d' "); and-connection means (7) defining a connection plane (7a) perpendicular to said third support plane (6a) and comprising at least two first rigid bars (70), each defining a first non-deformable connection direction (70a), and two second rigid bars (71), each defining a second non-deformable connection direction (71a), wherein said first bars (70) are instantaneously constrained to a first hinge (40) and to a second hinge (50) so that said first connection directions (70a) of said first bars (70) intersect in said connection plane (7a), and wherein said second bars (71) are instantaneously constrained to a second hinge (50) and to a third hinge (60) respectively so that said second connection directions (71a) of said second bars (71) intersect in said connection plane (7 a).

Description

Seismic device

technical field

The present invention relates to an anti-vibration device of the type specified in the preamble of the first claim.

In particular, the invention relates to a seismic joint suitable for absorbing vibrations of building type structures and infrastructure in order to stabilize the structure in the presence of seismic vibration phenomena.

Background technique

It is well known that several seismic solutions are currently used at the building level, which are also subject to the regulations in force in each country.

For example, at a regular level, some buildings are characterized by a statically indeterminate structure that is regular in plan and height, i.e. forms a compact and symmetrical plane, and in which all resistant vertical systems (such as frames and walls) are in the building extends over the entire height of the object.

Additionally, the masonry elements include a metal core that allows a predetermined deformability of the building's structure before catastrophic collapse is reached.

In addition, state regulations often state that a given elevated structure should have a single type of foundation unless it consists of separate units. In particular, the simultaneous use of pile foundations or mixed foundations and face foundations in the same structure must be avoided.

To ensure that the structure can resist seismic activity without major damage, even fairly strong seismic isolators can be used.

They are located between the foundation and the elevation structure to decouple the seismic frequency from the frequency of the elevation structure and avoid resonance phenomena. Using seismic isolators, the structure remains resilient even during severe earthquakes and retains the energy dissipation capacity provided by ductility.

An example of a seismic isolator is an LRB or lead rubber bearing, which has a lead core consisting of alternating layers of steel and elastomer connected by vulcanization, which can reduce horizontal displacement due to its high dissipation capacity.

The energy dissipation provided by the lead core through its plasticization allows to obtain equivalent viscous damping coefficients up to about 30%.

Due to the high dissipative capacity, horizontal displacement can be reduced compared to an isolation system with the same equivalent stiffness but with a smaller dissipative capacity.

These seismic isolators are usually circular, but can also be made in square cross-section, possibly with more than one lead core.

They are used on buildings, bridges or other structures during construction or seismic adaptation. They keep the structure and its contents safe.

系列(屈曲约束的轴向阻尼器)。Another type of isolator is provided by a buckling-constrained axial hysteresis dissipator such as

Series (buckling-constrained axial dampers).

耗散器会增加结构的刚度，这种效果对于符合将层间运动限制到损坏极限状态的法规要求(即根据有效的安全裕度允许结构断裂)是特别有用的。These isolators are nonlinear seismic devices whose behavior depends primarily on displacement. They are particularly suitable for use as dissipative supports for earthquake resistance through energy dissipation, especially for seismic adaptation of steel-framed buildings. Inserting these devices into the structural grid increases the dissipative capacity of the structure, thus significantly improving its response to earthquakes. before yielding,

Dissipators increase the stiffness of the structure, an effect that is particularly useful for complying with regulatory requirements to limit interlaminar motion to damage limit states (ie, allowing the structure to fracture according to an effective safety margin).

The described prior art suffers from several distinct disadvantages.

In particular, the described system, especially in the case of lead rubber bearings, is characterized by an extremely complex structure adapted to dissipate at least part of the deformation energy generated by seismic phenomena.

Consequently, these structures are very expensive in terms of cost and make it possible to solve the problem of seismic vibration management only in terms of damage tolerance, ie damage tolerance within damage limit states resulting from sometimes even plastic deformation phenomena.

Thus, the systems of the previous type described are reactive and irreversible beyond certain seismic thresholds.

In fact, all the devices known from the prior art only function in terms of the stiffness of the joints and the support structure.

SUMMARY OF THE INVENTION

In this context, the technical aim of the present invention is to design a seismic device capable of substantially overcoming at least some of the disadvantages mentioned.

Within the scope of said technical task, an important object of the present invention is to obtain an anti-seismic device capable of isolating the foundation of a building or supporting structure from the ground during eg seismic vibrational activities, thereby limiting deformation of the device.

Another important object of the present invention is to create an anti-vibration device capable of isolating a structure from vibrations, rather than merely interfering with the stiffness of the support joints of the structure.

In summary, another object of the present invention is to achieve an isolation device capable of reducing the freedom of movement experienced by a ground-supported structure with respect to the original reference system of said structure.

The technical and specific objects are achieved by the anti-vibration device as claimed in the appended claim 1 .

Preferred technical embodiments are described in the dependent claims.

Description of drawings

The features and advantages of the present invention will become apparent from the following detailed description of the preferred embodiment, wherein:

Figure 1 shows a schematic model of the device according to the invention in a free state;

Figure 2 shows a schematic model of a device according to the invention subjected to seismic stress;

Figure 3 is an example of an embodiment of the device according to the invention in a free state;

Figure 4 represents an embodiment of the device according to the invention subjected to seismic stress;

Figure 5 shows an example of a foundation comprising two devices of the invention arranged in a coplanar manner;

Figure 6 shows an example of a foundation comprising four superimposed devices of the present invention;

Figure 7a shows a second embodiment of the device according to the invention in a first configuration;

Figure 7b shows a second embodiment of the device according to the invention in a second configuration; and

Figure 7c shows a second embodiment of the device according to the invention in a third configuration.

Detailed ways

Measurements, values, shapes, and geometric references such as perpendicularity and parallelism, when used herein with words such as "about" or other similar terms such as "approximately" or "substantially", are to be understood In addition to measurement errors or inaccuracies due to production and/or manufacturing errors, and most importantly, except for slight deviations from the values, measurements, shapes or geometrical reference values associated therewith. For example, the term, if associated with a value, preferably indicates a divergence of no greater than 10% of the value.

Additionally, when terms such as "first," "second," "upper," "lower," "primary," and "secondary" are used, they do not necessarily refer to order, priority, or relative position, but may simply are used to more clearly distinguish the different components from each other.

Unless otherwise stated, measurements and data given in the text should be considered to have been obtained in Standard International Atmospheric ICAO (ISO2533).

Referring to the drawings, the reference numeral 1 generally denotes an anti-vibration device according to the present invention.

The seismic device 1 is preferably adapted to isolate the structure 2 with respect to the ground 3 .

Structure 2 is preferably a building-type structure. Thus, it can be a building, such as a bridge or other type of infrastructure.

In addition, the term "structure" 2 can be understood not only as a whole structure, but also as a part of the structure.

The device 1 may actually be accommodated in the foundation of the structure 2, or may be arranged in the middle part thereof. In one example, the device 1 is arranged at the bottom of the foundation of a residential building (ie a house). In the second example, the device 1 is arranged below a bridge support tower.

In a third example, the device 1 may be accommodated in a bridge section comprising a coupler between the support tower and the transport lane of the bridge itself.

The ground 3 can be any type of bottom, preferably flat.

The ground 3 may be, for example, solid soil or seabed.

Generally, the device 1 can be connected to the upper and lower parts.

The lower part may consist of ground 3 . However, it does not have to be ground 3, but can be composed of others.

Similarly, the upper part may consist of structure 2, but need not consist of it.

As mentioned above, in practice, the device 1 can take on different configurations, eg an arrangement in the middle region of the structure 2 .

The structural terminology of the device 1 is described in terms of its constituent parts after structural science modeling. This means that, for example, when referring to hinges and rods, they refer to physical elements that exhibit behavior similar to rods and/or hinges, especially in a two-dimensional plane, but have nothing to do with the actual physical parts used limit.

For example, a hinge can be made of several joints, just like a rod, which in terms of modeling can refer to rods, beams, or other elements suitable in this case to connect the hinge or have its own stiffness.

The support 1 preferably comprises a first support 4 , a second support 5 and a third support 6 .

The first support 4, the second support 5 and the third support 6 preferably define similar forms.

Preferably, the first support 4 defines a first support plane 4a.

The first support 4 is preferably connectable to the upper part, eg to the structure 2 or, in another example, to the third support 6 of the attachment 1 .

Thus, the first support plane 4a may consist of an interaction or constraint plane between the first support 4 and the structure 2 .

In addition, the first support 4 includes at least two first hinges 40 .

Hinges 40 are preferably made of mechanical joints that allow momentary connection of other elements. Such mechanical joints may be bolts adapted to preferably allow only a certain degree of transients of other elements, especially rotation about the hinge.

Such first hinges 40 are further preferably spaced apart from each other to define a first distance d'.

The first distance d' is preferably defined along the first support plane 4a.

In addition, it is preferably constant, so that the first support 4 defines a rigid rod.

Preferably, the third support 6 defines a third support plane 6a.

The third support 6 is preferably connectable to the lower part, for example to the ground 3 or the first support 2 of the second device 1 .

The term "lower" as well as the term "upper" used previously are defined with reference to the ground 3 along a vertical direction, eg defined by the acceleration of gravity.

Thus, the third support plane 6a may consist of an interaction or constraint plane between the third support 6 and the ground 3 .

Furthermore, the third support 6 includes at least two third hinges 60 .

Likewise, the third hinge 60 is preferably made of a mechanical joint that allows the other elements to be connected instantaneously. Such mechanical joints may be bolts adapted to preferably allow only a certain degree of transients of other elements, especially rotation about the hinge.

Such third hinges 60 are further preferably spaced apart from each other to define a third distance d"'.

The third distance d"' is preferably defined along the third support plane 6a.

Furthermore, it is preferably constant, so that the third support 6 defines a rigid rod.

Also, preferably, the distance d"' is equal to the first distance d'. Alternatively, in the example of Figs. 7a-7c, the first distance d' is greater than the third distance d"', preferably between 18% and 25% %, more preferably in the range of 21% to 23%.

Preferably, the second support 5 defines a second support plane 5a.

The second support 5 is preferably connectable to the first support 4 and the third support 6 .

Thus, the first support plane 5a is included between the first support plane 4a and the third support plane 6a.

In addition, the second support 5 includes at least two second hinges 50 . Preferably, in the example of Figures 7A-7c, the second support 5 comprises four second hinges 50, two second upper hinges 50a and two second lower hinges 50b.

The second hinge 50 is preferably made like the other hinges from a mechanical joint that allows the other elements to be connected instantaneously. Such mechanical joints may be bolts adapted to preferably allow only a certain degree of transients of other elements, especially rotation about the hinge.

Furthermore, such second hinges 50 are preferably spaced apart from each other to define a second distance d". Preferably, in the example of Figures 7a-7c, the second support 5 defines a second lower hinge 50b between said second hinges 50b. Two lower distances d ₁ ″, and a second upper distance d ₂ ″ is defined between said second upper hinges 50a.

The second distance d" is preferably defined along the second support plane 5a. Furthermore, it is preferably constant, so the second support 5 defines a rigid rod.

Preferably, the second distance d" and the first and third distances d' and d"' are not equal, but are smaller than them.

For example, the second distance d" may be at least 3% smaller than the third distance d"', more suitably 5% smaller.

Alternatively, in the example of Figures 7a-7c, the second lower distance d1" is smaller than said _first and said third distances d' and d"', preferably between 40% and 40% to the first distance d'. percentages in the range of 50%, and more preferably in the range of 44% to 48%. Furthermore, the second upper distance _d2 " is greater than said first and said third distances d' and d"' compared to the third distance d"', preferably greater than the third distance d"' at 9%- A percentage between 15% and more preferably between 11-13%.

The device 1 comprises connecting means 7 .

The connecting means 7 are preferably adapted to connect the supports 4 , 5 , 6 .

They preferably define a connection plane 7a. The connection plane 7a is perpendicular to the third support plane 6a. Therefore, it is substantially perpendicular to the ground 3 and connects the supports 4, 5, 6 perpendicularly with respect to the ground.

The connecting device 7 comprises at least two first rods 70 and two second rods 71 .

The first rod 70 is preferably substantially rigid. In addition, they each define a first connection direction 70a.

The first connection direction 70a corresponds to the main extension of the rod 70 and therefore to the axial direction.

The first connection direction 70a is also non-deformable.

Preferably, the first rod 70 is adapted to constrain the first support 4 and the second support 5 .

More specifically, the two first rods 70 are momentarily constrained to the first hinge 40 and the second hinge 50, respectively, such that the connection directions 70a of the first rods 70 intersect in the connection plane 7a.

In the example of Figures 7a-7c, the first lever 70 is momentarily attached to the first hinge 40 and the second upper hinge 50a, respectively, and defines substantially the same geometry as described.

Also, preferably, the second rod 71 is also rigid. In addition, they each define a second connection direction 71a.

The second connection direction 71a corresponds to the main extension dimension of the rod 71 and therefore to the axial direction.

The second connection direction 71a is also non-deformable.

Preferably, the second rod 71 is adapted to constrain the second support 5 and the third support 6 .

More specifically, the two second rods 71 are each momentarily constrained to the second hinge 50 and the third hinge 60 such that the second connection direction 71a of the second rods 71 intersects in the connection plane 7a.

In the example of Figures 7a-7c, the second rod 71 is momentarily constrained to the second lower hinge 50b and the third hinge 60, respectively, and defines substantially the same geometry as described.

The first rod 70 and the second rod 71 are preferably identical to each other, but may also be different.

Thus, the device 1, at least in the free state, substantially preferably defines two overlapping and correspondingly similar mirror-image structures with respect to the second support plane 5a.

These structures are given by the first support 4 , the first rod 70 and the second support 5 and the second support 5 , the second rod 71 and the third support 6 .

In the example of Figures 7a-7c, the distance between the first hinge 40 and the second upper hinge 50a in the vertical direction and in the aligned configuration (Figure 7a) is preferably very close to the first distance d', and preferably It differs from it by less than 3%, more preferably less than 1%. In addition, the distance between the second lower hinge 50b and the third hinge 60 in the vertical direction and in the aligned configuration (Fig. 7a) is preferably greater than the third distance d"', preferably between 12% and 20% between, more preferably between 15% and 17%.

These structures are also substantially similar to the articulated quads or "Chebyshev rails" used in "straight" sections when the side bars cross.

As already mentioned, the device 1 preferably defines a free state and at least one stress state.

In the free state, the device 1 is free with respect to the seismic stress and the first support plane 4a, the second support plane 5a and the third support plane 6a are parallel to each other. In this state, the device 1 is adapted to support the superstructure.

In a state of stress, the device 1 is stressed by means of a seismic stress defining at least one displacement x.

For example, the displacement x is arranged along the third support plane 6a and parallel to the connecting plane 7a in order to allow the device 1 to move according to the displacement x.

In detail, the first support 1 is subjected to a displacement x due to the seismic stress on the ground 3, so that all the supports 5, 6 arranged above also move with it.

Structurally, the device 1 so far described in the two-dimensional model may comprise pairs of first and second rods 70 , 71 .

These first and second rods 70 , 71 mutually coupled to the other first and second rods 70 , 71 are preferably parallel to the latter and are arranged along parallel and spaced connection planes 7a.

Additionally, the supports 4, 5, 6 may form or include a number of different structural elements.

For example, the first support member 4 may include the first support rod 41 , the second support member 5 may include the second support rod 51 , and the third support member may include the third support rod 61 .

In this configuration, the support rods 41, 51, 61 are preferably rigidly connected to the hinges 40, 50, 60, respectively.

This configuration can be used for a device 1 extending vertically in a two-dimensional manner (ie mainly along the connection plane 7a) and having two first rods 70 and two second rods 71 .

In particular, the device 1 may comprise adjacent pairs of first rods 70 and second rods 71 connected to adjacent pairs of support rods 41 , 51 , 61 .

In this case, the hinges 40, 50, 60 comprise spacers adapted to connect pairs of support rods 41, 51, 61 and rods 70, 71 and the device 1 is basically made of two structures, as before As described in the construction, the two structures are adjacent and constrained in a mirror-like fashion.

Optionally, the device 1 may include a first support plate, a second support plate and a third support plate.

In detail, the first support 4 may include a first support plate, the second support 5 may include a second support plate, and the third support may include a third support plate.

The support plates are preferably coplanar with the support planes 4a, 5a, 6a, respectively, and are adapted to connect the hinges 40, 50, 60, respectively. Such support plates can also be connected by two first rods 70 and two second rods 71 , or by several pairs of rods 70 , 71 .

Preferably, as already mentioned, the device 1 is suitable for use in seismic foundations of building type structures.

In this case, the seismic foundation comprises at least one device 1 and generally part of the structure 2 .

The device 1 can thus be arranged between two structural parts 2 or between the ground and the structural part 2 (usually the base).

The foundation comprising the device 1 can further provide different configurations.

They may comprise single or multiple devices 1 .

For example, the foundation may comprise a plurality of devices 1, wherein all the corresponding third support planes 6a are coplanar.

Furthermore, preferably all first support planes 4a are also coplanar.

For example, such a configuration is shown in FIG. 5 .

In addition, the seismic foundation may comprise a plurality of devices 1 arranged consecutively in an overlapping manner, and wherein, i.e., one of the third support planes 6a is integrated with the lower part (eg, the ground 3), and one of the first support planes 4a is integrated with The upper part (eg structure 2 ) is integrated and the other first and third support planes 4a and 6a are integrated with each other.

Also, preferably, the devices 1 do not overlap along the coplanar connection planes 7a, but each device 1 defines at least one free connection plane 7a that is skewed with respect to the connection planes 7a of the other devices 1, thereby allowing the foundation to absorb along the connection planes 7a is connected to multiple displacements x of the seismic stress in different directions, as shown in Fig. 6.

For example, the foundation may preferably comprise four overlapping devices 1 to achieve a column in which each device 1 defines a connecting plane that is skewed with respect to the adjacent plane, preferably equal to 45°. In this case, the device 1 may preferably have an octagonal perimeter.

In this way, a foundation is created that can absorb the seismic stress from the ground 3, the displacement of which is x- in four different directions.

Even two overlapping devices 1 defining mutually perpendicular connection planes 7a are sufficient to dampen all coplanar forces, since the forces can always be separated along two perpendicular axes.

The functions of the apparatus 1 described above in terms of structure are as follows.

When in the free state, all support planes 4a, 5a, 6a are parallel to each other and the rods 70, 71 preferably intersect at points included in the geometrical axis of the device 1 .

When the device 1 transitions from a free state to a stressed state due to the application of a seismic stress on the first support 4 with a displacement x, it will experience a displacement x if the first support 4 is parallel to the connection plane 7a.

When the first support 4 moves and normally vibrates, the intersection of the rods 70 , 71 deviates from the axis of the device 1 and the second support plane 5 a is inclined corresponding to the inclination of the second rod 71 .

Similarly, the first rod 70 and the first support plane 4a are inclined with respect to the second support plane 5a.

If the first support plane 4a and the third support plane 6a are integrally constrained to the upper and lower parts, respectively, characterized by sufficient values of the moment of inertia, the limits of which are easily detectable according to the dimensions of the device 1 from experimental tests, The first support 4 and the third support 6 then remain parallel during the movement of the device 1 .

In this case, the support planes 4a, 6a remain parallel and only the second support plane 5a is inclined together with the rods 70, 71 performing the opposite rotation. More specifically, when the second support plane 5a is rotated, the support plane can only translate back and forth along a plane parallel to the ground 3 or in a direction perpendicular to the ground 3 .

However, for low-intensity or low-amplitude vibrational stresses, the latter motion is extremely limited and negligible.

Thus, the device 1 allows to obtain a basic "floating" effect when the structure 2 is subjected to the seismic stresses present on the ground 3 .

The device 1 according to the invention has important advantages.

Indeed, the device 1 allows to absorb the stresses originating from seismic activity in a dynamic and mechanical manner, ie without resorting to deformable elements.

Thus, the device 1 allows to absorb movements and displacements x imposed by seismic stress not only due to the rigidity of the constituent elements, but also due to the movement mechanism included in the device 1 .

Indeed, with regard to the size and configuration of the device 1 or the foundation comprising it, the vibration modes of seismic stress can be completely absorbed by the relative movement of the first support plane 4a with respect to the third support plane 6a.

This absorption occurs in a completely stable manner, as the device 1 tends to return to a free state when unforced. Thus, the free state achieved by the device 1 is a stable equilibrium state.

In summary, the device 1 allows reducing the freedom of movement experienced by the structure 2, eg relative to the ground 3, since it is not allowed to rotate about an axis parallel to the first support plane 4a.

Changes may be made to the invention described herein without departing from the scope of the inventive concept as defined in the claims.

For example, the supports 4, 5, 6 may be constrained together by elastic elements and/or dampers adapted to control and, if necessary, alter the dynamic response of the device 1 to seismic stresses .

Examples of this type of embodiment are shown in FIGS. 3 and 4 .

Preferably, such an elastic element may be a common spring, and the damper may be of the hydraulic type, and may be provided in which, for example, the first hinge 40 is connected to the second hinge 50 by means of said elastic element and/or the damper, the second The hinge 50 can in turn be connected to the configuration of the third hinge 60 .

These can be passive or active types. The device 1 can also actively compensate for seismic motion.

Within the stated scope, all details may be replaced by equivalent elements and may be of material, shape and size as required.

Claims (11)

1. An anti-seismic device (1) for seismic isolation of a structure (2) with respect to a ground (3), characterized by comprising:

-a first support (4) defining a first support plane (4a) that is integrally connectable to an upper portion, such as the structure (2), and comprising at least two first hinges (40) defining a first constant reciprocal distance (d');

-a second support (5) defining a second support plane (5a) and comprising at least two second hinges (50) defining a second constant reciprocal distance (d ");

-a third support (6) defining a third support plane (6a) that can be integrally connected to a lower part, for example the ground (3), and comprising at least two third hinges (60) defining a third constant reciprocal distance (d' "); and

-connection means (7) defining a connection plane (7a) perpendicular to said third support plane (6a) and comprising at least:

-two first rigid bars (70), each defining a first non-deformable connection direction (70a) and adapted to constrain said first support (4) and said second support (5), and

-two second rigid bars (71), each defining a second non-deformable connection direction (71a) and adapted to constrain said second support (5) and said third support (6),

-said first bars (70) are each instantaneously constrained to one of said first hinges (40) and to one of said second hinges (50) so that said first connection directions (70a) of said first bars (70) intersect in said connection plane (7a), and

-said second bars (71) are each instantaneously constrained to one of said second hinges (50) and to one of said third hinges (60) so that said second connection directions (71a) of said second bars (71) are crossed in said connection plane (7 a).

2. The device (1) according to claim 1, wherein the first distance (d ') and the third distance (d' ") are equal and the second distance (d") is smaller than the first and third distances (d ', d' ").

3. The device (1) according to any one of the preceding claims, wherein the second distance (d ") is at least 3% smaller than the third distance (d'").

4. Device (1) according to any one of the preceding claims, wherein said supports (4, 5, 6) and said connection means (7) define at least two superimposed "chebyshev guides".

5. Device (1) according to any one of the preceding claims, comprising a plurality of pairs of said first and second bars (70, 71) parallel to each other along parallel and spaced apart connection planes (7 a).

6. Device (1) according to any one of the preceding claims, wherein said supports (4, 5, 6) each comprise at least one support bar (41, 51, 61) respectively adapted to rigidly connect said hinges (40, 50, 60).

7. Device (1) according to any one of the preceding claims, wherein said supports (4, 5, 6) each comprise at least one support plate (42, 52, 62) respectively coplanar with said support plane (4a, 5a, 6a) and respectively adapted to rigidly connect said hinge (40, 50, 60).

8. Device (1) according to any one of the preceding claims, comprising two pairs of two second hinges (50).

9. An anti-seismic foundation of a structure (2), comprising a device (1) according to any one of the preceding claims and at least a portion of said structure (2), said structure (2) being a building-type structure.

10. An anti-seismic foundation according to the preceding claim, comprising a plurality of said devices (1), wherein said respective third support planes (6a) are all coplanar.

11. An anti-seismic foundation according to any one of the preceding claims, comprising a plurality of said devices (1), wherein said devices (1) are arranged in succession overlapping, one of said third support planes (6a) being integral with the lower portion, one of said first support planes (4a) being integral with the upper portion, said other first (4a) and third (6a) support planes being integral with each other, and each of said devices (1) defining at least one of said connection planes (7a) which is inclined with respect to said connection plane (7a) of said other device (1), so as to allow said foundation to absorb a plurality of seismic stresses (x) in different directions along said connection plane (7 a).

Images