Classifications

• • E—FIXED CONSTRUCTIONS
  • E04—BUILDING
  • E04H—BUILDINGS OR LIKE STRUCTURES FOR PARTICULAR PURPOSES; SWIMMING OR SPLASH BATHS OR POOLS; MASTS; FENCING; TENTS OR CANOPIES, IN GENERAL
  • E04H9/00—Buildings, groups of buildings or shelters adapted to withstand or provide protection against abnormal external influences, e.g. war-like action, earthquake or extreme climate
  • E04H9/02—Buildings, groups of buildings or shelters adapted to withstand or provide protection against abnormal external influences, e.g. war-like action, earthquake or extreme climate withstanding earthquake or sinking of ground
  • E04H9/021—Bearing, supporting or connecting constructions specially adapted for such buildings
  • E04H9/023—Bearing, supporting or connecting constructions specially adapted for such buildings and comprising rolling elements, e.g. balls, pins
• • E—FIXED CONSTRUCTIONS
  • E04—BUILDING
  • E04H—BUILDINGS OR LIKE STRUCTURES FOR PARTICULAR PURPOSES; SWIMMING OR SPLASH BATHS OR POOLS; MASTS; FENCING; TENTS OR CANOPIES, IN GENERAL
  • E04H9/00—Buildings, groups of buildings or shelters adapted to withstand or provide protection against abnormal external influences, e.g. war-like action, earthquake or extreme climate
  • E04H9/02—Buildings, groups of buildings or shelters adapted to withstand or provide protection against abnormal external influences, e.g. war-like action, earthquake or extreme climate withstanding earthquake or sinking of ground
  • E04H9/021—Bearing, supporting or connecting constructions specially adapted for such buildings
  • E04H9/0215—Bearing, supporting or connecting constructions specially adapted for such buildings involving active or passive dynamic mass damping systems

Definitions

• Seismic dissipation module made up of compression-resistant spheres immersed in a variable low density material.
• the present invention concerns the industry for making seismic isolators, namely devices used for isolating the load-bearing structure of buildings from the effects of an earthquake and consists of a seismic dissipation and isolation panel or module made up of compression-resistant spheres, made of sintered alumina, bound by variable low density substances, polyurethane foams or polystyrene or other similar material, to be used in new buildings by placing it between a reinforced concrete bed to be made on the ground and the foundation structures of the building, so that, in the event of an earthquake, there can be movements of the building independent from those of the ground on which it is built, so absorbing and isolating the seismic wave and therefore reducing the effects on the structures until, in theory, they cancel them.
• Seismic events are the cause of considerable damage to both concrete and masonry buildings, with well-known consequences on the life of many people. Buildings are anchored to the ground by various types of foundations; they are consequently totally affected by the seismic wave that propagates through the ground to the foundations and therefore to the building, so producing forces that cause considerable stresses to the structural masses, which it is attempted to remedy by laying considerable dimensions of structures and of metal reinforcements that can withstand these forces as much as possible. To contain the uncertainties due to the uncertainty of the determination of the structural modelling parameters and guarantee good behaviour of the structures under seismic actions, specific measures must be adopted, which are listed below, aiming at ensuring ductility characteristics to the structural elements and to the building as a whole.
• the base of the isolated building can move in all horizontal directions compared to the foundations; therefore, after a movement, it is necessary for the building to return to its original position, if the residual movements are not of small magnitude compared to the building.
• the base of the building must be provided with suitable re- centring systems, also called auxiliary devices, whose function is to dissipate energy and/or re-centre the system and/or to provide lateral constraint of the structure.
• Devices that can re-centre the structure and also dissipate energy may include hydraulic devices or devices based on the particular mechanical properties of Shape Memory Alloys (SMA). These materials, typically made up of nickel- titanium alloys, have the ability to "remember" their original shape, which is unusual for other types of materials.
• SMA Shape Memory Alloys
• the foundation system must be provided with high extensional stiffness in the horizontal plane and with sufficient flexural stiffness.
• the structural elements of the foundations which must be sized on the basis of the stresses transmitted to them from the structure above, must have non- dissipative behaviour, irrespective of the structural behaviour attributed to the structure bearing down on them.
• the foundation-isolators-structure system can dissipate the seismic energy of the ground: the dissipation is almost exclusively concentrated in the isolation devices, which dissipate the seismic energy transmitted to them from the foundations at the expense of large plastic deformations, through wide hysteresis cycles.
• This allows the superstructure to have a response practically in elastic field by remaining almost immobile compared to the motion of the ground. This considerably changes the seismic input, since, by reducing the accelerations transmitted to the building, the response capacity of the structure to the ultimate collapse strength and to the extreme state of damage is considerably raised.
• these devices In addition to protecting the load-bearing structure, these devices also allow the non-structural parts and all it contains to be protected.
• this technology allows the prevention of cracks or damage to infills, partition walls, installations/sy stems or to goods inside buildings, such as museums or libraries, data processing centres, etc. This allows the damage caused to the structures by an earthquake to be minimized or completely eliminated, so maintaining unchanged the activity carried on in it, even after the occurrence of a severe telluric event.
• the isolated structure behaves almost like a rigid body that tends to remain still compared to the vibrations of the ground.
• Isolators made of elastomeric material and steel are made up of layers of elastomeric material (natural rubber or suitable artificial materials) alternated with steel plates, having the predominant function of confining the elastomer, and are arranged in the structure so as to withstand the rated horizontal actions and deformations through actions parallel to the position of the layers and of the vertical loads through actions perpendicular to the layers.
• They are usually of circular design, but can also be made with square or rectangular section. They are characterized by reduced horizontal stiffness, high vertical stiffness and appropriate dissipative capacity.
• Elasto-plastic isolators are made up of elements that stay elastic when there are just vertical loads but plasticize when there are horizontal actions higher than a set threshold.
• elasto-plastic isolators Thanks to their high dissipation capacity, elasto-plastic isolators have the task of limiting the transfer of stresses to the substructures, and so guarantee a better response of the entire construction to a seismic event.
• Sliding or rolling isolators made up respectively of steel and Teflon supports and of supports on roller or spheres, are all characterized by low friction resistance values. Therefore, whereas for elasto-plastic isolators and for those made of elastomeric material and steel, the damping needed to contain the relative movements of the two separate structures is ensured by the strongly hysteretic behaviour of the material with which they are made, for sliding isolators and for rolling isolators, it is necessary to place suitable energy dissipators in parallel.
• viscoelastic dissipators exploit the viscous behaviour of materials such as plastics, mineral oils and silicone.
• elasto-plastic dissipators exploit the plasticization of metallic materials to dissipate energy in hysteresis cycles.
• friction dissipators exploit the friction between suitably treated metal surfaces that slide against each other.
• elasto-plastic isolators and those made of elastomeric material and steel are particularly vulnerable in the event of fire and must be suitably protected from such an eventuality or used together with devices that can replace them if they are destroyed.
• the new aseismic marble base is particularly suitable for statues vertically developed that have a very small base and are therefore particularly vulnerable to horizontal seismic actions, which can compromise their balance and cause them to tip over.
• the rolling mechanical isolators described in patent "MICALI" No. 1146596 are made entirely of steel or other suitable rigid material and each made up of a pair of circular concave elements with a sphere interposed of diameter not less than the sum of the heights of the two concavities.
• WO 99/07966 discloses a friction ball, made of either plastically deformable homogeneous material (lead, aluminium, brass, iron, steel, etc.) or elastomeric material, which is deformed when it supports a weight; said deformation generating a frictional force which resists rolling motion in the deformed ball.
• a panel or module to be used in new buildings to be installed between a reinforced concrete bed to be made on the ground and the foundation structures of the building, such as for example a reinforced concrete beam or foundation bed, so that, in the event of an earthquake, there can be movements of the building independent from those of the ground on which it is built, so absorbing and isolating the seismic wave and therefore reducing the effects on the structures until, in theory, they cancel them.
• Fig. 1 shows a plan view and a cross-sectional view of a prefabricated panel or module (1) made up of spheres (2), with a pre-set centre-to-centre distance between them that changes depending on the point load (load acting on a single point of the sphere) that it is wished make the sphere support, made of sintered alumina, bound by variable low density substances, polyurethane foams or polystyrene or other similar material (3);
• Fig. 2 is a cross-section:
• FIGS 3 and 4 show an alternative embodiment of the prefabricated panel or module (1) in which:
• Fig. 3 shows a plan view and a cross-sectional view of a prefabricated panel or module (1) made up of spheres (2), whose movement capacity is localized inside a circular area (9) and having a pre-set centre-to-centre distance between them that changes depending on the point load (load acting on a single point of the sphere) that it is wished make the sphere support, made of sintered alumina, bound by variable low density substances, polyurethane foams or polystyrene or other similar material (3);
• Fig. 4 is a cross-section:
• substructure or "first foundation”, the part of the structure situated below the interface of the isolation system and that includes the foundations, generally having negligible horizontal deformability and directly subject to the movements imposed by the seismic movement of the ground;
• the polyurethane or polystyrene or other similar material (3) of the prefabricated module (1) is used to support the concrete casting of the superstructure in the first 28 days of curing of the said concrete.
• the sintered alumina with which the spheres (2) of the prefabricated module (1) are made is a ceramic material resulting from the sintering of alumina, a substance present in bauxite, consisting of a thermal and mechanical process through which the powdered materials are reduced to a compact mass of a given shape; it combines the advantages of aluminium alloys and of powder metallurgy.
• the sintered alumina spheres are characterized by very high hardness and compressive strength and therefore high resistance to axial loads, such that laboratory tests show that a sintered alumina sphere, about 5 cm in diameter, subjected to a vertical axial load of 9,000 kg, does not show any plastic effect on its contact surface.
• the thickness of the prefabricated panel or module (1) is equal to the diameter of the spheres (2), (example: 3-5-8 cm, etc.) with a variable surface area that is suitable for transport, (example: 3.00 x 1.50 m, etc.) or below standard sizes.
• the sintered alumina spheres (2) should be covered with a suitable additive on the market, a silicone release agent, to ensure that the polyurethane or polystyrene or other similar material (3) does not come into contact with the spheres (2), since these must be allowed the possibility of rotating independently from the structure made of binding material (3) that surrounds them.
• the possibility of multidirectional rotation of the spheres (2) in the event of an earthquake absorbs and isolates the horizontal oscillating motion of the ground (5) without transmitting stresses to the superstructure of the building (7), which, by inertia, will tend to maintain the position, so reducing the well- known disastrous effects.
• the binding material (3), of the sintered alumina spheres (2), at low and variable density allows their controlled rotation.
• the prefabricated module (1) does not undergo deformations during the earthquake, since the sintered alumina spheres (2) have high compressive strength and are without plastic consequences; consequently, the response, with dissipative-isolating effect, will always be the same even during the next earthquake shock, without the panel (1) components ever having to be replaced.
• the centre-to-centre distances between the sintered alumina spheres (2) may, in particular cases, be adapted to the requirements of the weights above so as to optimize the point load on the sphere (2).
• the binding material (3) of the sintered alumina spheres (2) is shaped in such a way that each sphere (2) must move inside a localized circular area (9) that delimits its possibility of movement and, in the same way, allows its controlled rotation.

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• Engineering & Computer Science (AREA)
• Architecture (AREA)
• Business, Economics & Management (AREA)
• Emergency Management (AREA)
• Environmental & Geological Engineering (AREA)
• Civil Engineering (AREA)
• Structural Engineering (AREA)
• Vibration Prevention Devices (AREA)
• Buildings Adapted To Withstand Abnormal External Influences (AREA)

Priority Applications (6)

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Publications (1)

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Country Status (9)

Cited By (2)

Families Citing this family (8)

Citations (3)

Family Cites Families (28)

• 2011
  • 2011-11-21 IT IT000066A patent/ITMC20110066A1/it unknown
• 2012
  • 2012-11-19 JP JP2014541570A patent/JP2014533783A/ja active Pending
  • 2012-11-19 CA CA2856108A patent/CA2856108A1/en not_active Abandoned
  • 2012-11-19 EP EP12790430.8A patent/EP2783057B1/en active Active
  • 2012-11-19 US US14/359,778 patent/US20140345210A1/en not_active Abandoned
  • 2012-11-19 CN CN201280057154.3A patent/CN103946468A/zh active Pending
  • 2012-11-19 MX MX2014005823A patent/MX2014005823A/es not_active Application Discontinuation
  • 2012-11-19 WO PCT/EP2012/004798 patent/WO2013075814A1/en active Application Filing
• 2014
  • 2014-05-20 CL CL2014001320A patent/CL2014001320A1/es unknown

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