With the release of the new regulatory documentation, the NERA program has officially acquired the status of an instrument for simulating soil-column reactions for the expected seismic impact. In the article some peculiar features of carrying out calculations of seismic influences are considered. It is shown that the initial dependence of the shear modulus G and the damping coefficient ξ on the shear strain γ, applied in the program for clay soils, does not fully characterize this type of rocks. The obtained results of calculations indicate the necessity of using a greater number of dependencies for a correct description of the seismogeological section
Keywords: seismic impacts, calculation, NERA, seismic microzoning.

Kaurkin M.D., Chief specialist of the Department of Geophysics , «Gazprom Geotechnology» LLC, Ph.D., (Candidate of Science in Technics), Moscow, 1-ya Magistral’naya, d. 11/2.. E-mail: kaurkin_m@mail.ru.

Romanov V.V., Associate Professor of the Department of Geophysics MGRI, Ph.D., (candidate of science in Technics). 119485, Moscow, Miklukho-Maclay St., 23. E-mail: roman_off@mail.ru.

1. Aptikaev F.F. Instrumental scale of seismic intensity. Moscow : Science and Education, 2012.
2. State Standard 25100-2011. Soils. Classification.
3. Zaalishvili V.B. A computational method for estimating seismic properties of soils // Earthquake resistant construction. Safety of buildings. 2014. No. 5. P. 16-31.
4. Kaurkin M.D., Romanov V.V. Calculation of seismic effects in specialized programs NERA and EERA // Journal «Engineering Surveys». Moscow : Geomarketing Publishing House, 2017. No. 4. P. 54-62.
5. Assessment of the impact of ground conditions on seismic hazard. Moscow : Publishing House «Science», 1988. 223 p.
6. Pavlenko O.V. Seismic waves in the soil layers: nonlinear behavior of the soil during strong earthquakes in recent years. Scientific world, 2009, 284 p.
7. SR-006-98. Determining the initial seismic effects for the project basis / Gosatomnadzor of Russia. Moscow, 1998. 72 p.
8. SR 14.13330.2014. Construction in seismic areas / Ministry of Construction and Housing of the Russian Federation. Moscow, 2014. 125 p.
9. SR 283.1325800.2016 Construction objects of increased responsibility. The rules of seismic zoning. Moscow, 2017. 21 p.
10. Ulomov V.I. Seismic safety of Russia in danger // FORUM International. 2005. No. 6. P. 74-75.
11. Bardet J.P., Ichii K., Lin C.H. User’s manual for EERA: A computer program for Equivalent-linear Earthquake site Response Analysis of Layered Soil Deposits. Los Angeles : Department of Civil Engineering, University of Southern California, 2000. 40 p.
12. Bardet J.P., Tobita T. NERA: A computer program for Nonlinear Earthquake site Response Analyses of Layered Soil Deposits. Los Angeles : Univ. of Southern California, 2001. 44 p.
13. Idriss I. Earthquake Ground Motions at Soft Soil Sites // Second International Conference on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics, March 11-15, 1991, St. Louis (Missouri). V. 3. P. 2265-2272.
14. Ishibashi I., Zhang X.-J. Unified dynamic shear moduli and damping ratios of sand and clay // Soils and Found. 1993. V. 33, Issue 1. P. 182-191.
15. Iwan W.D. On a class of models for the yielding behavior of continuous and composite systems // Journal of Applied Mechanics, ASME. 1967. V. 34. P. 612-617.
16. Kramer S.L. Geotechnical Earthquake Engineering. USA : New Jersey : Upper Saddle River : Prentice Hall Inc., 1996. 653 p.
17. Mróz Z. On the description of anisotropic workhardening // Journal of Mechanics and Physics of Solids. 1967. V. 15. P. 163-175.
18. Effects of Soil Model on Site Response Analyses / Mahdy Khari, Khairul Anuar Bin Kassim, Azlan Bin Adnan and Hossein Moayedi // Asian Journal of Scientific Research. 2014. V. 7, Issue 1. P. 76-84.
19. Schanbel P.B., Lysmer J., Seed H.B. SHAKE: A computer program for earthquake response analysis of horizontally layered sites : Earthquake Engineering Research Center, Report No. UCB/EERC72/12. Berkeley : University of California, 1972. 102 p.
20. Vucetic M., Dobry R. Effect of soil plasticity on cyclic response // Journal of Geotechnical Engineering. V. 117, No. 1. P. 89-107.
21. Zhang J., Andrus R.D., Juang C.H. Normalized shear modulus and material damping ratio relationships // Geotech. Geoenviron. Engin. 2005. V. 131, No. 4. P. 453-464.