RU128211U1 - SEISMIC ISOLATING FOUNDATION (OPTIONS) - Google Patents

Abstract

1. A seismic insulating foundation containing a foundation plate, a base immersed on the bottom of the pit, and a damping element placed between them in the form of a multilayer bed of spherical bearings of at least three different diameters, limited by gaskets installed on the walls of the pit, with each bearing contains internal and external metal spheres, the space between which is filled with a slightly viscous non-freezing liquid, for example, antifreeze, and metal balls adjacent to both of these m areas, with kacheniya.2. A seismic insulating foundation containing a foundation plate, a pile base with a head immersed in the ground, and a damping element placed between them in the form of a cartridge covering a multilayer bed of spherical bearings of at least three different diameters and made to move the pile base around the headband, each bearing contains internal and external metal spheres, the space between which is filled with a low-viscosity non-freezing liquid, for example, antifreeze, and metal with balls adjacent to both of these spheres with the possibility of rolling, and the tip of the pile base is equipped with limiters for moving the cartridge. 3. The foundation according to claim 2, in which the base is multi-pile with a tip in the form of a concrete grillage.

Description

Technical field

The utility model relates to the field of construction, namely, the construction of seismic insulating foundations of buildings and structures in areas prone to earthquakes.

State of the art

Known seismic insulating foundation of the company Spie Batignolle [Civil Engineering Journal, No. 3, 2010 p.56-60, Fig. 6], selected as a prototype.

The prototype contains a foundation plate, a base with a head, immersed at the bottom of the pit, and a damper element located between them. In the prototype, the damper element is made in the form of sequentially installed neoprene gaskets and friction plates. In a stationary state, the friction forces between the friction plates ensure the motion of the foundation plate relative to the base. Under seismic effects, friction forces are overcome and the neoprene pad damps the vibrations of the foundation plate relative to the base, preventing the destruction of the building or structure if the frequencies and modes (spatial forms) of their seismic vibrations correspond to the characteristics of the damper element and the foundation as a whole.

The disadvantage of the prototype is the limited ranges of vibration damping in frequency and mode and the inefficiency of seismic isolation in a wide range of frequencies and modes of seismic vibrations that actually occur during various types of earthquakes.

Utility Model Essence

The technical result of the utility model is the expansion of the spectra of modes and frequencies in which the foundation provides reliable seismic isolation of buildings and structures.

The subject of a group utility model are two variants of a seismic isolating foundation.

The seismic insulating foundation according to the first embodiment contains a base plate, a base immersed on the bottom of the pit, and a damping element placed between them in the form of a multilayer filling of spherical bearings of at least three different diameters, limited by gaskets installed on the walls of the pit, with each bearing contains internal and external metal spheres, the space between which is filled with a weakly viscous non-freezing liquid, such as antifreeze, and metal balls adjacent both these spheres to roll.

The seismic insulating foundation according to the second embodiment contains a base plate, a pile base with a head immersed in the ground, and a damping element placed between them in the form of a cassette covering a multilayer bed of spherical bearings of at least three different diameters and made to move along the head of the pile base, with each bearing containing internal and external metal spheres, the space between which is filled with a low-viscosity non-freezing liquid, for example, toso ohm, and metal balls adjacent to both said areas in rolling and headroom pile foundation is provided with limit stops the cassette.

The last option has a development, which consists in the fact that the base is multi-pile with a head in the form of a concrete grillage.

Brief Description of the Drawings

Figures 1 and 3 show the foundations of the first and second variants, respectively, and figure 2 shows the design of the bearings used in both variants of the utility model.

Implementation of developmental utility model options

The foundation according to the first embodiment (Fig. 1) contains a foundation plate 1, a base 2, immersed on the bottom of the pit, and a damping element placed between them in the form of a multilayer backfill from spherical bearings 3 having different diameters, for example, 0.25, 0.5 and 1.0 m. The multilayer backfill is limited by gaskets 4 mounted on the walls of the pit.

Bearing 3 (figure 2) contains inner 5 and outer 6 metal spheres, the space 7 between which is filled with a low-viscosity non-freezing fluid, such as antifreeze, and metal balls 8 adjacent to the spheres 5 and 6 with the possibility of rolling.

The foundation according to the second embodiment (Fig. 3) contains a foundation plate 1, a pile base 9 immersed in the ground with a head 10. Between the plate 1 and the head 9 there is a damping element in the form of a cassette 11, covering a multilayer backfill of bearings 3 having different diameters, for example , 0.25, 0.5 and 1.0 m. The head 10 is equipped with limiters 12.

The cassette 11 is arranged to move along the head 10 of the pile base 9 within the limits defined by the limiters 12. In the second embodiment of the foundation, bearings of the design described above are also used (FIG. 2).

The foundation in the first embodiment is constructed as follows.

In a previously prepared and protected from collapse pit, the bottom is covered with gravel and concreted with the formation (after building strength with concrete) of crushed stone-concrete base 2. Then, gaskets 4 are mounted on the walls of the pit (for example, in the form of packages of used car tires). Then the free volume of the pit is layer-by-layer filled with bearings 3 of at least three different diameters, starting with bearings of a smaller diameter. As the formation of a multilayer backfill, the diameters of the bearings 3 in its layers increase. The base plate 1 above the multilayer filling of the bearings 3 is formed by the stepwise pouring of concrete by the sliding formwork method.

The foundation works according to the first option as follows. During earthquakes, the seismic vibrations of the base immersed in the soil affect the multilayer filling of the bearings 3. Due to the ability of the outer sphere 6 of each bearing 3 to slide along balls 8 rotating in the antifreeze medium relative to the inner sphere 5, the bearings 3 elastically move relative to each other (like bubbles of a fluidized bed) in accordance with the forces acting on them. Thus, the base plate 1 is isolated from the direct effects of vibrations of the base 2. With large amplitudes of vibrations, the plate 1 can move in horizontal directions, and the multilayer filling of the bearings 3 remains between the gaskets 4.

As a result, the vibrations of the base 2 are damped in a wide range of frequencies and modes, isolating the base plate 1 from the destructive seismic effect.

The foundation according to the second option is constructed as follows.

After the construction of a pile foundation 9 in the soil having one or more piles, a head 10 is mounted on it with limiters 12 to move the cassette 11. In the case of several piles, the head 10 is made in the form of a grill connecting them. Pa head 10, a cassette 11 is installed, into which spherical bearings 3 of at least three different diameters are poured in layers, starting from bearings of a smaller diameter. As the formation of a multilayer backfill, the diameters of the bearings 3 in its layers increase. The base plate 1 is mounted on a multilayer backfill of bearings 3, covered by a cassette 11.

The foundation according to the second embodiment works similarly to the foundation according to the first embodiment of the utility model, except that the cassette 11, filled with layers of bearings 3, has the additional possibility of local movements along the surface of the head 10 between the stops 12.

The proposed foundation options are able to isolate a building, bridge, viaduct and other structures from seismic vibrations of a wide range of frequencies and modes, due to the fact that the layers of bearings of different diameters, freely moving relative to each other, effectively dampen mechanical vibrations acting on them, regardless of their direction in space.

Using the variants of the proposed seismic isolating foundation increases the seismic resistance of buildings and structures installed on it.

Claims (3)

1. A seismic insulating foundation containing a foundation plate, a base immersed on the bottom of the pit, and a damping element placed between them in the form of a multilayer bed of spherical bearings of at least three different diameters, limited by gaskets installed on the walls of the pit, with each bearing contains internal and external metal spheres, the space between which is filled with a slightly viscous non-freezing liquid, for example, antifreeze, and metal balls adjacent to both of these m spheres to roll. 2. A seismic insulating foundation containing a base plate, a pile base with a head immersed in the ground, and a damping element placed between them in the form of a cartridge covering a multilayer bed of spherical bearings of at least three different diameters and made to move along the head of the pile the base, with each bearing containing internal and external metal spheres, the space between which is filled with a low-viscosity non-freezing liquid, for example, antifreeze, and metal kimi balls adjacent to both said areas in rolling, and the headroom of the pile base is provided with limit stops the cassette. 3. The foundation according to claim 2, in which the base is multi-pile with a tip in the form of a concrete grillage.

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