The advantages and disadvantages of the NEHRP soil classification

DOI: 10.37153/2618-9283-2021-1-10-31

Authors:  
Rubric:     Seismic zoning   
Key words: seismic soils properties classification, site class, model, response spectrum, dynamic coefficient, average model, shear wave velocity, seismic rigidity, continuity
Annotation:

The influence of local ground conditions on the parameters of seismic vibrations is the subject of study in seismic microzonation. This section of engineering seismology underwent radical changes at the end of the last century. The Commission on Seismic Safety of the National Institute of Building Sciences of the United States, as part of the implementation of the National Earthquake Damage Reduction Program, developed new NEHRP Recommendations, which are significantly different from all that has been used in the world practice of anti-seismic construction. The main provisions of this NEHRP classification have been adopted in many national building codes, including Eurocode 8 and Kazakhstan's seismic regulations. One of the essential features of the classification is the use of the average values of the velocities of transverse waves and the densities of the ground thickness with a thickness of 30 meters. In Russia, the provisions of the NEHRP norms have not yet been properly developed. Currently, the issue of extending the norms of Kazakhstan to the entire territory of the CIS countries is being considered. For this reason, the article examines in detail both the advantages and disadvantages of the NEHRP Recommendations in order to extract useful experience and adapt to the realities of Russian anti-seismic construction. In particular, the error in the representation of the parameters of the soil mass by average values is shown. The ways of overcoming the identified shortcomings of the description of the soil mass with the help of model representations are outlined

Used Books:

1. Building Seismic Safety Council (1997) National earth­quake hazard reduction program (NEHRP) recommended provisions for seismic regulations for new buildings and other structures. Part 1: Provisions (FEMA 302). Building Seismic Safety Council, Washington. DC.

2. European Committee for Standardization (2003). Eurocode 8: Design of structures for earthquake resistance – Part 1: General rules, seismic actions, and rules for buildings, EN 1998-1:2003, Brussels, 229 p.

3. Rekomendatsii po opredeleniyu seismicheskikh nagruzok, sootvetstvuyutshikh inzhenerno-geologicheskim i seismologicheskim usloviyam Respubliki Kazakhstan [Recommendations on seismic loads, corresponding to engineering-geological and seismological conditions of the Republic of Kazakhstan], KazNIISA, Almaty, 2011. (In Russian)

4. SP 14.13330. 2014. Construction in seismic areas. М., 2014. (In Russian)

5.Seismicheskoe raionirovanie SSSR [ Seismic Zonation USSR], Moscow, Nauka Publ., 1968, 476 p. (In Russian)

6. Medvedev S.V. Inzhenernaya seismologiya. M.: Gosstroiizdat.1962. 284 p. (In Russian)

7. Dobry R., Borcherdt R., Crouse C.B., Idriss L.M., Joyner W.B., Martin G.R., Power M.S., Rinne E.E. and Seed R.B. (2000). New site coefficients and site classifi­cation system used in recent building seismic code provi­sions. Earthquake Engineering, 16, pp. 41-67.

8. Klimis N.S., Margaris B.N. and Koliopoulos P.K. (1999). Site-dependent amplification functions and response spec­tra in Greece. Journal of Earthquake Engineering, 3, pp. 237-270.

9. Barani A., De Ferrari R., Ferretti G., and Eva C. (2008). Assessing the effectiveness of soil parameters for ground response characterization and soil classification. Earth­quake Spectra, 24, pp. 565-597.

10. Gallipoli M. and Mucciarelli M. (2009). Comparison of site classification from V_s30, V_s<i0 and HVSR in Italy. Bul­letin of the Seismological Society of America, 99, pp. 340-351.

11. Zaslavsky Y., Shapira A., Goldstein M. et al. (2012). Questioning the applicability of soil amplification factors as defined by NEHRP (USA) in the Israel building standards. Natural Science, 4 (2012), pp. 631-639.

12. Anbazhagan P., Neaz Sheikh and Aditya Parihar (2013). Influence of Rock Depth on Seismic Site Classification for Shallow Bedrock Regions. Natural Hazards Review, May 2013, pp.108-121.

13. Respubliranskie stroitel'nye normy. RSN 60-86 [RSN 60-86; State Construction Norms], Moscow, Stroiizdat Publ. 1986. (In Russian)  

14. SP 283.1325800.2016. High critical building objects. Rules of seismic microzonation. М., 2016. (In Russian)

15. Bardet J.P. and Tobita T. NERA. F Computer Program for Nonlinear Earthquake Site Response Analyses of Layered Soil Deposits. University of Southern California. Department of Civil Engineering. April, 2001, p. 44.

16. Kharkevich A.A. Theoretical bases radio. М.: Sviaz’izdat. 1957. 348 p. (In Russian)

17. Aleshin А.S. The continuum theory of seismic microzonation. М., 2017. 300 p. (In Russian)