JP2014533783A - Seismic dissipation module composed of compression resistant spheres embedded in variable low density material - Google Patents

Abstract

The present invention is used in the industry for manufacturing seismic vibration isolation devices, i.e. reinforced concrete beds (4) which are used to insulate building load structures from the effects of earthquakes and which are to be produced on the ground (5). ) And the substructure (6) of the building (7), by placing it between the variable low density material, urethane foam or polystyrene or other similar material to be used in the new building ( 3) Made of sintered alumina, bound by 3), in the case of an earthquake, absorbs and isolates seismic waves and thus theoretically reduces the impact on the building until they negate the effect Seismic dissipation and insulation panel or module composed of compression resistant spheres (2) so that the movement of the building can be independent of the movement of the ground on which it is built An apparatus consisting of one). [Selection] Figure 4

Description

  The present invention relates to a reinforced concrete bed and building foundation to be used in the industry for manufacturing seismic vibration isolation devices, i.e. to insulate building load-bearing structures from the effects of earthquakes and to be produced on the ground. Made of sintered alumina, bound by a variable low density material, urethane foam or polystyrene or other similar material to be used in a new building by placing it between buildings In the case of an earthquake, the movement of the building will cause the ground on which it is built so that it absorbs and isolates seismic waves and thus theoretically reduces the impact on the building until they negate the effect It relates to a device consisting of an earthquake dissipating and insulating panel or module composed of compression resistant spheres, which can be independent of the movement of

  Seismic events are a source of considerable damage to both concrete and masonry buildings with well-known consequences for the lives of many people. The buildings are fixed to the ground by various forms of foundations; they therefore completely affect the seismic waves propagating through the ground to the foundation and thus to the building so as to generate forces that cause considerable stress on the structural mass Attempts have been made to improve as much as possible by placing buildings and metal reinforcements of considerable scale that can withstand these forces.

  Ensure ductility characteristics for structural elements and for buildings as a whole to contain uncertainty due to uncertainty in determining structural modeling parameters and to ensure good behavior of buildings under seismic action The specific measures listed below, aimed at that, must be adopted.

  When an earthquake occurs, the base of an insulated building may move in all horizontal directions compared to the foundation; therefore, if after movement the residual movement is not as small as compared to the building, the building Needs to return to its original position. To that end, the foundation of a building is also referred to as an auxiliary device whose function is to dissipate energy and / or bring the system back to the center and / or introduce lateral constraints on the building There must be an appropriate re-centering system.

  Devices capable of returning the building to the center and further dissipating energy can include hydraulic devices or devices based on shape memory alloys (SMA) of specific mechanical properties. These materials are generally composed of nickel-titanium alloys and have the ability to “remember” their original shape, which is unusual for other types of materials.

  In general, the movement experienced by an insulated building as a result of seismic action must be within acceptable values that contain the dimensions of the structural joints and should not cause problems in equipment / system connections. . For insulated buildings, flexible connections should in fact be envisaged for all equipment / systems connected from the ground to the superstructure.

  Without permanent movements that are incompatible with the baseline extremes, the foundation building must withstand the effects resulting from the response of the building on the ground and above.

  The building must be equipped with a structural system that ensures rigidity and resistance to the two perpendicular horizontal components of seismic action.

  The foundation system must have high expansile stiffness in the horizontal plane and sufficient bending stiffness.

  Foundation structural elements that must be dimensioned to the base of the stress transferred from them to the building must have non-dissipating behavior, regardless of the structural behavior attributed to the building over them. Don't be.

  By inserting a vibration isolator between the foundation and the high building, the seismic frequency is decoupled from the high building frequency, thereby preventing the occurrence of resonance.

  In the case of seismic stress, the insertion of a vibration isolator allows the appropriate period of vibration of the building to be increased to move it away from the region of the response spectrum with greater acceleration.

  In order to reduce the transmission of energy supplied by seismic effects on the superstructure, this effectively causes the building to be dynamically disconnected from the ground (the “filter” effect). Finally, as a result of this, this foundation-vibration isolator-building system can dissipate the seismic energy on the ground: the dissipation is almost exclusively concentrated in the isolator, which is a large plastic deformation through a wide history cycle. Dissipate the seismic energy transmitted from the foundation to them at a price. This allows the superstructure to have a response in the elastic field in effect by remaining substantially stationary compared to the ground motion. This significantly changes the seismic input as reducing the acceleration transmitted to the building significantly increases the building's ability to respond to ultimate crush strength and damage extremes.

  In addition to protecting the load bearing structure, these devices further allow the non-structural parts and all it contains to be protected. In fact, as a result of the almost complete absence of intermediate landing deformation (drift), this technique can cause cracks in embedded, partition walls, equipment / systems, or items in buildings such as museums, libraries, data processing centers, etc. Make it possible to prevent damage. This allows damage caused to the building by the earthquake to be minimized or eliminated so as to keep the activities continued to follow even after the occurrence of a severe earth event To.

  During an earthquake, an insulated building behaves almost like a stiff body that tends to remain stationary compared to ground vibrations.

  Using seismic vibration isolation devices, buildings are designed to remain in the elastic field even during the most severe earthquakes and to keep the energy dissipation capability afforded by ductility intact.

  Currently, in the field of earthquake engineering, there are three categories of vibration isolator and various types for each category.

  Vibration isolation devices made from elastomeric material and steel have the dominant function of confining the elastomer, and the normal horizontal action and deformation through the action parallel to the position of the layer and the vertical load through the action perpendicular to the layer It is composed of layers of elastomeric material (natural rubber or suitable artificial material) that are alternated by steel plates placed in the building to withstand.

  They are usually of circular design, but can also be made of square or rectangular sections. They are characterized by reduced horizontal stiffness, high vertical stiffness, and adequate dissipation capability.

  An elasto-plastic vibration isolator consists of elements that remain elastic when there is only a vertical load, but plasticizes when there is a horizontal action that exceeds a set threshold.

  Thanks to their high dissipation capability, elastoplastic vibration isolators have the task of limiting the transmission of stress to the substructure, thus ensuring a better response of the entire building to seismic events.

  Sliding or rotational vibration isolators constructed from steel and Teflon supports and from supports on rollers or spheres, respectively, are all characterized by low frictional resistance values. Therefore, to contain the relative movement of two separate buildings by virtue of the strong hysteretic behavior of the materials from which they are made, against elasto-plastic vibration isolators and against those made of elastomeric material and steel. While the necessary damping is ensured, it is necessary to arrange an appropriate energy dissipator in parallel to the sliding vibration isolator and to the rotational vibration isolator.

  The dynamics of these types of vibration isolators are complex because the sliding process is inherently non-linear.

  Some dissipators, called viscoelastic dissipators, take advantage of the sticky behavior of materials such as plastic, mineral oil and silicone. Other dissipators, called elastoplastic dissipators, utilize the plasticization of metallic materials to dissipate energy in a hysteresis cycle. Ultimately, so-called friction dissipators utilize friction between appropriately treated metal surfaces that slide against each other.

  In addition to the aging of the elastomer (rubber) and thermoplastic polymer (Teflon), the physical and chemical properties of the adhesive used to bond the steel plate to the rubber, also possibly placed in parallel with the sliding or rotational vibration isolator The physical and chemical properties of linear chain organosilicon polymers (silicone oils and greases) used in viscoelastic dissipators are also important for durability purposes.

  In addition, elastoplastic vibration isolation devices and those made of elastomeric material and steel are particularly brittle in the event of a fire and are adequately protected from what may happen of this kind or they are destroyed If so, it must be used with a device that can replace them.

  In current technology, there is also an ENEA seismic marble base for the bronze statue of Riace.

  These belong to the seismic vibration isolation system developed by ENEA for the protection of sophisticated equipment. These are passive and / or semi-passive non-intrusive seismic protection devices composed of two superimposed blocks of marble on their inner surface, with two depressions in specular reflection on the two blocks, The outer shape is hollowed out to be a spheroid with four marble spheres placed on it, and their rotation allows the large movement, low stiffness and low friction requirements that are required to maximize seismic isolation give.

  When there is an earthquake, it is the lower part of the foundation to be subjected to seismic action, and this transmits stress upwards because they are completely absorbed by the movement of the spheres inside the cavity that are hollowed out into the marble It is possible to move with the ground without doing it. The movement of the sphere makes the less rigid protection system with very low friction a property that minimizes seismic stress or renders them almost ineffective. The new seismic marble foundation has a very small foundation, and therefore is particularly vulnerable to vertically created images, especially vulnerable to horizontal seismic action that can compromise their balance and cause them to flip Is suitable.

  When used for large areas, this type of seismic insulation is used for homes and apartments because the materials used to make this device are very expensive both in terms of raw materials and installation Therefore, the use of these seismic foundations with marble spheres is limited to artistic works.

  Different types of seismic dissipators or vibration isolators on the market are very expensive and are made by highly specialized techniques, and even their installation cannot be performed by ordinary construction companies.

  The rotary mechanical vibration isolator described in US Pat. No. 6,057,086 is made entirely from steel or other suitable hard material, and each is inserted with a diameter equal to or greater than the sum of the two concave heights. Consists of a pair of circular concave elements with a sphere. According to this patent, a lower bed or mesh building is established by setting a concave element in a mesh building with two reinforced concrete beds or one mounted directly on the ground and the other on a sphere. Only the object is forced to undergo any horizontal seismic motion of the ground, while the upper one is lower concave compared to the upper one placed in it, thanks to the rotation of the lower sphere Since it is forced to receive only a short upward lateral movement due to the momentary movement of the element, it can remain almost stationary according to the gentle inertia of the building.

  The limitations of these rotary mechanical vibration isolators are related to the compressive strength of the sphere due to the small contact surface with the associated concave rotating seat and the resulting need for large numbers or large dimensions.

  (Patent Document 2) discloses a friction ball made of either a plastically deformable homogeneous material (lead, aluminum, brass, iron, steel, etc.) or an elastomer material that deforms when supporting weight. The deformation action generates a frictional force that withstands the rotational movement of the deformed ball.

  The limits of these friction balls are related to both the high cost of the material from which they are made and the low durability over time in terms of their resistance.

MICALI, Italian Patent No. 1146596 International Patent No. 99/07966

  In the case of repeated earthquakes that have very low cost but technical characteristics with respect to density and strength, it is possible to have the same response for each event, and the components need to be replaced Therefore, it is an object of the present invention to manufacture a seismic vibration isolator composed of raw materials that do not include any maintenance costs and are easy to find on the market. Furthermore, the vibration isolator provides excellent insulation from rising moisture, assuming the quality of the aggregate of sintered alumina spheres.

  In the case of an earthquake, a building that is independent of the movement of the ground on which it is built, so as to absorb and isolate seismic waves and thus theoretically reduce the effect on the building until they negate the effect It is another object of the present invention to produce a seismic vibration isolation device that can withstand multi-directional seismic input so that it can be moved in the same manner.

  It is an object of the present invention to produce a seismic vibration isolator that can prevent structural sizing and, at the same time, the transmission of induced seismic forces on a building to provide reduced maintenance of the building's function. Is a further purpose.

  According to the invention for a panel or module to be used in a new building to be installed between a reinforced concrete bed to be produced on the ground and a building foundation such as a reinforced concrete beam or foundation bed In the case of an earthquake, these and other targets are obtained, so as to absorb and insulate seismic waves and thus theoretically reduce the impact on the building until they negate the effect Allowing it to become a building movement independent of the movement of the ground on which it is built.

  Additional features and advantages of the present invention will become more readily apparent from the description of the preferred but non-exclusive embodiments of the product that is the subject of this patent application, which is illustrated by way of example and not limited in the drawing unit, where:

Point load (load acting on a single point of the sphere) required to make a sphere support made of sintered alumina bound by variable low density material, urethane foam or polystyrene or other similar material (3) Shows a plan view and a cross-sectional view of a pre-made panel or module (1) composed of spheres (2) with a preset center-to-center distance between them varying according to It is made of pre-made, composed of spheres (2) made of sintered alumina and bound by variable low density material, urethane foam or polystyrene or other similar materials (3): Reinforced concrete bed (4) mounted on a panel or module (1), ground (5) and surrounded at the top by an "insulating interface", where the "insulating interface" is in operation of the insulation system Means a separate surface; • Reinforced concrete beams or foundation beds (6); • Buildings with columns (8) (7). 3 and 4 show an alternative embodiment of a pre-made panel or module (1), where: Spherical support made of sintered alumina, whose mobility is localized inside the circular region (9) and bound by a variable low density material, urethane foam or polystyrene or other similar material (3) A pre-made panel or module composed of spheres (2) having a preset center-to-center distance between them that varies according to point loads (loads acting on a single point of the sphere) A plan view and a sectional view of (1) are shown; The following cross-sections: • Bonded by a variable low density material, urethane foam or polystyrene or other similar material (3) with the ability to move within the local region (9) and made of sintered alumina A reinforced concrete bed (4) of a foundation made of pre-made panels or modules (1), ground (5) and surrounded at the top by an "insulating interface", consisting of a shaped sphere (2), “Insulating interface” here means the separation surface on which the insulation system is operating; • Reinforced concrete beams or foundation beds (6); • Buildings with columns (8) (7).

In the description below, the following terms are used, for which a definition is given below:
-"Substructure" or "First foundation", located below the interface of the insulation system, which has negligible horizontal deformation and is directly subjected to the movements forced by the ground seismic motion. And part of the building including the foundation;
“Superstructure” or “second foundation”, the part of the building located above the insulating interface and thus insulated.

  A pre-made module (1) polyurethane or polystyrene or other similar material (3) is used to support the concrete casting of the superstructure during the first 28 days of curing of the concrete.

  Sintered alumina from which the spheres (2) of the pre-made module (1) are fabricated is a ceramic material, resulting from the sintering of the alumina, the powdered material being reduced to a compact mass of a predetermined shape therethrough. Present in bauxite consisting of thermal and mechanical processes; it combines the advantages of aluminum alloys and powder metallurgy.

  Sintered alumina spheres are characterized by very high hardness and compressive strength and thus a high resistance to axial loads, so laboratory tests have shown that the sintered test is subject to a vertical axial load of approximately 5 cm in diameter and 9,000 kg. It shows that the sintered alumina spheres do not show any plastic effect on their contact surfaces.

The advantages of aluminum alloys are as follows:
A low specific weight (approximately 2.7 g / cm ³ );
-Good corrosion resistance;
-Excellent mechanical properties;
-Good wear resistance;
-Good fatigue resistance;

The advantages of powder metallurgy are as follows:
-Low manufacturing costs;
-Control with good tolerance without further processing;
-The possibility of obtaining complex shapes at a limited cost.

  The thickness of the pre-made panel or module (1) is the diameter of the sphere (2) with a variable surface area suitable for transport (eg 3.00 × 1.50 m, etc.) (eg 3-5). −8 cm, others) or below standard size.

  The installation of these pre-made panels or modules (1) envisions that they are placed in contact with each other on a horizontal plane between the first foundation and the second foundation.

  Sintered alumina spheres (2) must be expected to rotate independently of the building made of the binding material (3) that surrounds them, so polyurethane or polystyrene or other similar materials ( In order to ensure that 3) does not come into contact with the sphere (2), it should be covered with a suitable additive on the market, a silicone release agent.

  The possibility of multidirectional rotation of the sphere (2) in the event of an earthquake is to absorb and insulate the horizontal vibration movement of the ground (5) without transmitting stress to the superstructure of the building (7). There is a tendency to maintain position by inertia so as to reduce the known catastrophic effects.

  The binder material (3) of the sintered alumina spheres (2) allows their controlled rotation at a low and variable density. Since the sintered alumina sphere (2) has a high degree of compressive strength and is not accompanied by plasticity, the pre-fabricated module (1) is not subject to deformation during an earthquake; With the panel (1) components never have to be replaced, the response is always the same even during the next earthquake shock.

  For the system of foundation (6), the normal and non-plastic effects on the concrete due to the sintered alumina spheres (2) of the vibration isolators, inside and outside the tear bands of the vibration isolators Both of the normal strength concrete Rck30 can be used (test performed in the laboratory). For concrete loads on the foundation (6), foundation concrete with appropriate strength is used.

  The center-to-center distance between the sintered alumina spheres (2) can be adapted to the above weight requirements in certain cases in order to optimize the point load on the sphere (2).

  According to a further embodiment of this prefabricated panel or module (1) for seismic dissipation and insulation, the boundaries of its possibility of movement are determined and likewise its controlled rotation is enabled. The binding material (3) of the sintered alumina sphere (2) is shaped in such a way that each sphere (2) has to move inside the shaped circular region (9).

  The above-described materials and dimensions of the present invention illustrated in the accompanying drawings and later claimed can be varied according to requirements. Moreover, all details may be replaced by other technical equivalents without departing from the protection scope of the patent application of the present invention.

1 Pre-made panel or module 2 Sphere 3 Bundling material 4 Reinforced concrete bed 5 Ground 6 Foundation 7 Building 8 Pillar 9 Circular area

Claims (4)

  The seismic, consisting of pre-made panels or modules (1) to be installed between the reinforced concrete bed (4) to be produced on the ground (5) and the foundation structure (6) of the building (7) A seismic dissipation module that insulates the load-bearing structure of a building from the influence, wherein the pre-made panel or module (1) is a pre-made panel or module with a preset center-to-center distance therebetween Consisting of a compression resistant sphere (2) placed inside the module (1), the pre-made panel or module (1) is variable, the compression resistant sphere (2) being made of sintered alumina Seismic dissipation module characterized by being bound by low density material, urethane foam or polystyrene or other similar material (3).   The earthquake-dissipating module (1) according to claim 1, characterized in that the sintered alumina spheres (2) are covered with suitable additives on the market, such as silicone mold release agents.   The thickness of the pre-made panel or module (1) is equal to the diameter of the sintered alumina sphere (2) with a variable surface area suitable for transport. Earthquake dissipation module (1).   The variable low density material, urethane foam or polystyrene or other similar material (3) that binds the sintered alumina spheres (2) is a circular region (9) where each sintered alumina sphere (2) is localized. Seismic dissipation module (1) according to claim 1, characterized in that they are shaped in such a way that they have to move inside.

Images