Seismic protection devices for buildings

Аннотация

It is shown that the earthquake resistance of buildings during construction in difficult ground conditions has a number of features. Traditional seismic isolation systems are used without regard to the properties of weak soils and do not consider these features. New, effective design solutions are proposed that meet the requirements of improving earthquake resistance and construction in difficult ground conditions. Keywords: seismic isolation, protection devices, earthquake resistance, spatial foundation platform, sliding layer, hard pole, anti-seismic measures, flexible system. We have discussed above the methods of our ancestors to increase the seismic strength of buildings and their seismic protection. These anti-seismic measures and other seismic protection methods prove that our ancestors knew the physical nature of the impact of seismic forces on buildings and structures, as well as the law of their impact. Because these anti-seismic measures, which ensure the earthquake resistance of buildings, can be developed because of incessant research, observation, and deep analysis of experimental results for centuries, over the years, as earthquake data has been collected, the qualitative nature of this data has changed dramatically. In particular, the wide application of scientific results obtained in the field of physics to this field has opened wide opportunities for humanity in the fight against earthquakes and has further expanded the scope of their knowledge about earthquakes. A new approach to solving this problem has emerged in European science. In addition to measures aimed at increasing the load-bearing capacity of normal structures, attention has been paid to reducing the inertial forces that occur in structures during an earthquake. Measures taken in this direction are considered active measures of seismic protection of buildings. In 1925, M. M.Viscordini was the use of gula support or spherical columns with lower or upper 65 support in the basement part of the building for the seismic protection of buildings. After this incident, a number of new ideas in the seismic protection of buildings and structures during the national economy. We will briefly touch on them below. As mentioned above, seismic protection (seismic isolation) of buildings and structures from earthquakes is the oldest and most promising method of active seismic protection. The method of seismic protection of buildings is divided into the following types according to the constructive solution of its implementation: The lower floor of buildings is a flexible system of load-bearing foundations. In the 30s of the last century, the idea of protecting buildings from seismic impact by making the first or basement part flexible was put forward. This method is based on the fact that when the lower floor is made flexible, the seismic reaction of buildings is always smaller than that of buildings with a single structural scheme. When making the first floor of buildings flexible, it is necessary to take into account the nature of the stresses due to intensive rotational movement in some parts of the building may exceed those of ordinary buildings. In foreign countries (England, France, the USA, New Zealand), resin metal supports, which are installed between the foundation of the upper load- bearing structure, are widely used in the seismic protection of buildings. This support is shown schematically in Fig. 1. Initially, these structures were used for seismic protection of bridge supports, and later, such structures were widely used for seismic protection of buildings. The French-developed GAPEC-type seismic protection support system shown in the picture consists of layer construction and layers of steel sheets and neoprene material. This type of support has high resistance to compression, stretching, and twisting due to the elastic properties of the neoprene material. These supports were used as seismic protectors in a series of four-story buildings. The building with this resin metal layer of seismic protection was built by the company "Unitika" in Yatiyo, Japan, and tested in a natural experiment. The building was supported by six piers and two additional shock absorbers with above-ground structures, and this system of protective structures performed well during the powerful earthquake that occurred on July 2, 1983. During this earthquake, even when the ground vibration amplitude reached 20 cm, no damage was observed inside the building. According to the Japanese scientists who developed this construction, these seismic support supports reduce the seismic acceleration during an earthquake by 3-5 times. Kinematic support systems As mentioned above, in 1925, M. Viscordini proposed the use of gula supports or columns with spherical supports as seismic protectors in buildings. Since then, despite the fact that there are a lot of proposals by experts for the use of rocking supports in seismic protection, these structures are rarely used. Figur