The invention may be applied to all buildings made of frames or diaphragms of reinforced concrete, metal or concrete with rigid reinforcement, such as living buildings, industrial buildings, nuclear plants, bridges, offshore drilling platforms, extraction and drilling equipment, water towers, towers and radio and television aerials, chimneys, refrigeration towers, etc.

When the invention has to be used for extant constructions, it will obtain a significant decrease of the destructive effects, caused by the seismic movements and high winds.

The invention ensures the decrease of the strength elements dimensions and the exploitation safety increase, when it is applied for new constructions.

Description of the Prior Art Romanian patent no. 95152 relates to a vibrations diminution method which consists in the base structure isolation therefore it is possible an easy relative displacement of the structure to foundation footing, in the purpose of the seismic safety.

The method is about a preparation phase in order to build a reinforced concrete support frame, to foundation release that there are on adequate depth. Afterwards the extant foundations footing are prepared for the support frame structure cooperation. After that a few holding plates of the seismic insulation devices, will be inserted. Next the reinforced concrete support frame pours. It ensures the superstructure non-deflating. After that a few insulated foundations footing are built, according to a method settled beforehand and provisory supporting elements will be mounted, for instance, pneumatic cylinders.

Above the insulation foundations - footing it will be built a new foundation footing which is equipped with special dwellings and the seismic insulation devices will be mounted into those place dwellings.

At last a construction lateral locking will be prepared on the underground area with the space-cushion buffer keeping.

The drawbacks of the method are a lot of labor, therefore a high cost, as well as a high fulfillment time.

For the strength structures vibrations decrease, caused by the seismic movements or high winds, it is known a device made of mobile bearers, having the form of a pendulum, mounted between the structure and its foundation, in order to allow an independent displacement in a horizontal plan.

The structures are engaged to the foundations - footing by a joint made of a sheared strut in a horizontal plan, so that the relative displacements are restricted.

The joint opposite side, the structure lateral leans, by a reinforced rubber bearer on an energy absorber made of storage bin that will be filled up with sand which works by the friction with foundation-footing. That device is described in Romanian patent no.

80391.

The drawback device is that it can't be used for existents constructions and more over, the device using for the new constructions will result the drawback, that the elastic materials waste their features due to repeated dynamics stress, hence the device efficiency will be significant decreased.

Summary of the invention The invention solves a technical problem that consists in the strength structures dynamic features modification by redistributed the contribution of owns modes to final efforts.

According to the invention, the strength structures vibrations diminution method consists in that there is an additional theoretical loading to each level with a certain suspended metal bodies which are gravitational pendulums.

The efforts and deformations new state will be recalculated, the suspended bodies scheme placing will be settled to each level, as well as the suspended bodies dimensions will be settled, at last, at each

level of new or extant strength structure on horizontal strength elements.

Close to vertical strength elements, it places a certain suspended metal bodies that will be inserted in a few vibration diminution devices case.

The own frequency of metal bodies is equal to the first own strength structure frequency. The metal bodies weight is 40+50 kilos.

The metal bodies overall weight on each level represents about 0.25 percent of the floor weight. The vibrations diminution devices are uniform distributed on the floor. The cases are fixed with dowels and screws that penetrate into a few holes that are built in the horizontal strength elements.

When the first vibrations begin to come out, the suspended metal bodies of the vibrations diminution devices, begin to oscillate inside the case, before the structure. The suspended metal bodies consume a part of the energy produced by the horizontal dynamic stress.

The diminution device, in accordance with invention is made of a metal body that is suspended to a rod. An extremity of rod is inserted in the metal body and the opposite one is inserted to a stiff assembled case to a metal plate. The metal plate is equipped with a few mounting holes on a strength structure element.

An elastic assembly called damper is inserted on the outer surface of the metal body and settled with screws. It has the shape of a fastener on which there are inserted some elastic elements on a circle bow shape. These circle bows are disposed in a normal plan to the metal body. A few clinker rings may be fixed on the interior surface of the clamp.

The clinker rings and elastic elements are pretensionated to assembly and support on the case internal surface.

When the invention is applied, it will be obtained the following advantages: - The invention can be used at extant constructions as well at new different types and destinations constructions.

- The efforts and deformations strength structures are decreased with 25i50 percent when the invention is used.

- Significant diminution of loads at the foundations doesn't require safety precautions against the vibrations.

- There are not necessary maintenance operations because the vibrations diminution devices present a high reliability.

- When the invention is used, important reductions material are obtained, hence the cost of the new strength structures decreases.

- The cost of extant constructions consolidation will decrease about 5...6 times when the invention is applied and about 10... 15 times of fulfillment duration as well.

- The invention doesn't require people, furniture and equipment evacuation.

Brief Descrintion of the Drawings In the drawings, wherein similar reference characters denote similar element through the several views: Fig.l - is a plan view of the strength structure, on it there are many vibrations diminution devices A.

Fig.2 - is a vertical section of the vibrations diminution device A, that is mounted on a strength element 1.

Fig.3 - is a horizontal section along lines I - I of fig. 2.

Fig.4 - is a horizontal section along lines I - I of fig. 2, in a second embodiment.

Description of the Preferred Embodiment The diminution method of the strength structures vibrations applied to the extant constructions consists in a first calculation stage based on the extant teclmical documentation or measuring taker.

The construction efforts and deformations are evaluated taking account the frequencies and periods, the calculations being based on the usual relations and theorems.

The pendulum metal bodies number is calculated taking account the level weight and adequate surfaces. The metal bodies will be placed on the strength elements to adequate level.

These metal bodies are materialized as vibrations diminution device A, the composition will be presented.

The suspended metal body of the vibrations diminution devices A, is defined by its weight and suspended element length. The weight and length metal body may be evaluated, requiring the condition that metal body frequency being equal to first frequency strength structure.

The metal bodies number and vibrations diminution devices A may be evaluated, so that the metal bodies overall weight being 0.25 percent of floor weight, as it is shown in this relation:

nxGc=0.25/ 100xGp where: n - represents the vibrations diminution devices A number: Gp - represents the floor weight: Gc - represents the suspended metal body weight. It is recommended that Gc = 40...50 kilos.

For instance, for an extant block of flats, a certain level of it being illustrated in fig. 1, considering that the floor 1 has the surface of 340 m2 and the weight Gp = 340 tones, applying the relation we will obtain: n = 0.25/100 x 340/0.05 = 17 The "n" vibrations diminution devices A will be placed on that level plan close to strength vertical elements, diaphragms 2 respectively.

Because of the supplementary weight represented by suspended metal bodies, having the own frequency equal to the own first frequency strength structure, the strength structure efforts and deformations are reevaluated resulting a theoretical decrease about 25 percent.

The vibration diminution devices A are changed in size, by iterative calculations, modifying in this way the own frequency of the suspended metal body, so that reevaluating the theoretical strength structure efforts and deformations, these are decreased about 40...50 percent. This decrease is due to the first come out vibrations, the suspended metal bodies, begin to oscillate before strength structure, spending a part of the energy produced by the dynamic stress.

After the second calculation stage is finished, it follows the physics execution of the vibrations diminution devices A that will be

fixed on horizontal strength elements - floors and beams - to each strength structure level according to the level plan.

The placing vibrations diminution devices A is fulfilled by screws and dowels that penetrate into the holes. The floors or beams are provided with those holes.

In the situation for new constructions, after the second calculation stage is finished, that theoretical reduces 40 - 50 percent of deformations and efforts state, the strength elements will be recalculated, reducing the size and weight of the strength structure elements.

After strength fulfillment is finished, according to the project, the vibrations diminution devices A will be mounted to each level in concordance with the same rules as those mentioned to extant buildings example.

In the both situations, the vibrations diminution devices A may be masked with furniture elements or being integrated in the furniture structure.

The vibrations diminution devices A, according to the invention (fig.2 and fig.3) is made of a cylindrical metal body 4 that is made of steel or cast iron. It is suspended to the rod 5 from closed case 6.

The cylindrical case 6 is coaxial to metal body 4. The rod 5 is made of elastic metal, for instance, arch wire. The rod 5 joints to case 6 and metal body 4, by screws 7, so that the pendulum made of metal body 4 and rod 5, is able to oscillate in a vertical plan and twists to fixed case 6.

An elastic assembly B is fixed on metal body outside by screws 7. This elastic assembly B limits and damps metal body 4 oscillations that come out inside the case 6.

The elastic assembly B is made of cylindrical fastener 8. The elastic arch belt or wire element extremities are inserted to the fastener 8 at equal distances.

As can be seen in fig.3, the arch elastic elements 9 are placed in the same horizontal plan that is normal to metal body 4 axis. The elastic elements 9 are orientated in the same direction.

In the another embodiment, as can be seen in fig.4, the elastic assembly B is made on fastener 8, on which are fixed elastic clinker rings 11, by the rivets 10. These rings 11 are partial superposed without interacting each other, but being able to be deform.

The elastic clinker rings 11 or elastic elements 9 radius r value is evaluated so that appears an easy radial pretension of the elastic elements 9 or 11, when the fastener 8 and elastic elements 9 or 11 are inserted into case 6.

The elastic elements 9 free extremities lean on the case 6 inner surface. In the example with elastic clinker rings 11, these compress radial each other, and are placed tangential to case 6 cylindrical surface.

The case 6 bottom side is welded on a plate 12. On the plate there are holes b, the fixing elements 3 being inserted into the holes b.

These fixing elements 3 ensure the whole vibrations diminution device A interlocking to strength element such as floor 1 where there are holes c.