ИСТИНА

Seismic micro-zoning (SMR) in Russia is carried out within the framework of engineering surveys for construction. The purpose of SMR is, firstly, the allocation within a certain territory of areas with an intensity of seismic fluctuations, different from the general seismic zoning of the territory of the Russian Federation, OSR-97 defined with a map. OSR-97, in turn, is a geophysical justification for the development and application of SNIP in the area of earthquake-proof construction. OSR maps characterize the degree of seismic hazard throughout the country and are used for socio-economic planning, rational land use and earthquake-proof construction. Secondly, SMR works are conducted to determine the maximum seismic impact on structures. Attention should also be paid to the fact that seismic hazard does not decrease, but grows in direct connection with economic development of seismically active territories and human impact on the lithospheric envelope of the Earth (construction of large structures, extraction of minerals, dense urban buildings, etc.). In general, due to the actual uniqueness of the geological and geophysical properties of the Earth's regions, the need for the whole range of works on SMR is determined by the importance of the facility and the ratio of the main estimated costs. These include, on the one hand, additional costs for design and construction in terms of increased intensity (scoring). On the other hand, there is the possibility of the emergence of costs for the possible strengthening of the base of the structure according to the indications of current seismicity. And, finally, the costs for eliminating the consequences of seismic impacts greater than those that were taken during design can be formed. Works on SMR for any parts of seismic zones can provide more precise seismic effects from earthquakes of this intensity in one direction or another. This refinement is possible up to ± 2 points on the MSK-64 intensity scale. This scale describes the impact on objects of construction of seismic oscillations, mechanical movements of the Earth's surface caused by earthquakes [1]. The paper presents the results of SMR at two construction sites in the Crimea. The upper part of section of site No. 1 (Sevastopol) is represented by porous limestones, which can be relatively easily eroded with the formation of karst voids. Site No. 2 (Gurzuf, the camp "Kiparisny", Artek) was located on the coastal slope and is characterized by pronounced landslide processes. At the first stage, seismic studies were performed at the construction sites, recording P- and S- refracted waves. As a result of the studies, seismic sections were calculated in the isolines of the velocity of propagation of P- and S- waves, as well as the values ​​of the parameter Vs/Vp. The depth of the investigations was about 15-25 m. Further, the distribution obtained in the medium for propagation velocity of elastic waves was used to further refine the seismic intensity of the construction area. At the second stage, calculations were made for seismic microzoning of construction sites using seismic rigidity methods, Nakamura and scenario earthquakes. As a result, the following results were obtained: • by the method of seismic rigidity, the Nakamura method and the method of scenario earthquakes of the construction site is characterized by an average increment of seismic intensity relative to the reference soil II category according to seismic properties: for a 10 meter "-0.3" point, for a 30 meter "-0.8" points; • Based on the results obtained by methods of engineering-geological analogies, seismic stiffnesses and the calculated method, the scale of the site No. 1 on the MSK-64 was 7.0 points; • Based on the results obtained by methods of engineering-geological analogies, seismic stiffnesses and the calculated method, the score of the site No. 2 on the MSK-64 was 7.7 points for the 10-meter layer and 7.2 points for the 30-meter layer.