{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,5,29]],"date-time":"2026-05-29T09:39:30Z","timestamp":1780047570085,"version":"3.53.1"},"reference-count":25,"publisher":"Geological Institute, Bulgarian Academy of Sciences","issue":"1","content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"published-print":{"date-parts":[[2021,4]]},"abstract":"<jats:p>Usually, soils with mainly fine grain-sized content, as loess, are considered to have low liquefaction potential. Regardless of this, many researchers have analyzed and presented much field evidence that silty soil (in particular loess) liquefaction occurred under certain conditions. In Bulgaria, the first loess river terrace (T1) within the Danube River lowland areas is covered by low plasticity silty loess with a thickness of 10\u201312 m. \u0422he groundwater level is often located between 5 m and 8 m in depth so that substantial part of loess deposits are saturated and immersed. Meanwhile, that region of North Bulgaria is under the influence of the Vrancea seismic zone in  Romania, which is able to generate strong earthquakes with magnitudes M\u22657.0. The present paper aims to assess the liquefaction potential of loess in a ground profile representative of the T1 loess river terraces by the so-called simplified procedure based on SPT, which is incorporated in the software code NovoLiq. The safety factor against liquefaction FSL is estimated at the respective depths in one-dimensional model of the ground profile for free-field conditions at varying peak ground accelerations amax. The critical amax, at which liquefaction of loess is possible according to the assumptions of the applied simplified procedure and the requirements of the National Annex of Bulgaria to Eurocode 8, has been established.<\/jats:p>","DOI":"10.52321\/geolbalc.50.1.37","type":"journal-article","created":{"date-parts":[[2021,4,16]],"date-time":"2021-04-16T15:44:44Z","timestamp":1618587884000},"page":"37-44","source":"Crossref","is-referenced-by-count":9,"title":["Liquefaction potential assessment of saturated loess"],"prefix":"10.52321","volume":"50","author":[{"given":"Doncho","family":"Karastanev","sequence":"first","affiliation":[{"name":"Geological Institute, Bulgarian Academy of Sciences, Acad. G. Bonchev Str., Bl. 24, 1113 Sofia, Bulgaria"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Boriana","family":"Tchakalova","sequence":"additional","affiliation":[{"name":"Geological Institute, Bulgarian Academy of Sciences, Acad. G. Bonchev Str., Bl. 24, 1113 Sofia, Bulgaria"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"29796","published-online":{"date-parts":[[2021,4,16]]},"reference":[{"key":"ref0","unstructured":"Andrews, D.C.A., Martin, G.R. 2000. Criteria for liquefaction of silty soils. Proceedings of the 12th World Conference on Earthquake Engineering, Auckland, New Zealand, p. 312."},{"key":"ref1","doi-asserted-by":"publisher","unstructured":"Berov, B., Ivanov, P., Frangov, G., Dobrev, N., Krastanov, M. 2017. Liquefaction susceptibility of quaternary deposits in Bulgaria. Proceedings of the 17th International Multidisciplinary Scientific GeoConference SGEM 2017, 29 June\u20135 July, 2017, Albena, Bulgaria, 17 (12), 499\u2013506, https:\/\/doi.org\/10.5593\/sgem2017\/12\/S02.064.","DOI":"10.5593\/sgem2017\/12\/s02.064"},{"key":"ref2","unstructured":"Boulanger, R.W., Idriss, I.M. 2014. CPT and SPT-based liquefaction triggering procedures. Report No. UCD\/CGM14\/01. University of California Davis, CA, 134 pp."},{"key":"ref3","doi-asserted-by":"publisher","unstructured":"Cetin, K.O., Seed, R.B., Der Kiureghian, A., Tokimatsu, K., Harder, L.F., Kayen, R.E., Moss, R.E.S. 2004. Standard penetration test-based probabilistic and deterministic assessment of seismic soil liquefaction potential. Journal of Geotechnical and Geoenvironmental Engineering 130 (12), 1314\u20131340, https:\/\/doi.org\/10.1061\/(ASCE)1090-0241(2004)130:12(1314).","DOI":"10.1061\/(asce)1090-0241(2004)130:12(1314)"},{"key":"ref4","unstructured":"EN 1998-5. 2004. Eurocode 8: Design of structures for earthquake resistance. Part 5: Foundations, retaining structures and geotechnical aspects. BDS EN 1998-5:2005.2007 (in Bulgarian)."},{"key":"ref5","unstructured":"EN 1998-5\/NA. 2012. Eurocode 8: Design of structures for earthquake resistance. Part 5: Foundations, retaining structures and geotechnical aspects. National annex to BDS EN 1998-5:2005\/NA:2012, 14 pp. (in Bulgarian)."},{"key":"ref6","unstructured":"Evlogiev, Y. 2019. Quaternary Geology and Geomorphology of the Danube Plain. Geological Institute, Bulgarian Academy of Sciences, Sofia, 268 pp. (in Bulgarian)."},{"key":"ref7","doi-asserted-by":"publisher","unstructured":"Fardis, M., Carvalho, E., Elnashai, A., Faccioli, E., Pinto, P., Plumier, A. 2005. Designers\u2019 Guide to EN 1998-1 and 1998-5. Eurocode 8: Design Provisions for Earthquake Resistant Structures. Thomas Telford Publishing, London, 279 pp., https:\/\/doi.org\/10.1680\/dgte8.33481.","DOI":"10.1680\/dgte8.33481"},{"key":"ref8","doi-asserted-by":"publisher","unstructured":"Guo, T., Prakash, S.1999. Liquefaction of silts and silt-clay mixtures. Journal of Geotechnical and Geoenvironmental Engineering 125 (8), 706\u2013710, https:\/\/doi.org\/10.1061\/(ASCE)1090-0241(1999)125:8(706).","DOI":"10.1061\/(asce)1090-0241(1999)125:8(706)"},{"key":"ref9","unstructured":"Idriss, I.M., Boulanger, R.W. 2008. Soil Liquefaction During Earthquakes. Monograph MNO-12. Earthquake Engineering Research Institute, Oakland, CA, 261 pp."},{"key":"ref10","unstructured":"Idriss, I.M., Boulanger, R.W. 2010. SPT-based liquefaction triggering procedures. Report No. UCD\/CGM-10-02. University of California Davis, CA, 136 pp."},{"key":"ref11","unstructured":"Karastanev, D. 1998. Influence of moisture content on strength behavior of loess. Proceedings of the International Symposium on Problematic soils, IS-Tohoku \u201998, Sendai, Japan, 457\u2013460."},{"key":"ref12","doi-asserted-by":"publisher","unstructured":"Kishida, H. 1969. Characteristics of liquefied sands during Mino-Owari, Tohnankai and Fukui earthquakes. Soils and Foundations 9 (1), 75\u201392, https:\/\/doi.org\/10.3208\/sandf1960.9.75.","DOI":"10.3208\/sandf1960.9.75"},{"key":"ref13","doi-asserted-by":"publisher","unstructured":"Pei, X., Zhang, X., Guoa, B., Wang, G., Zhang, F. 2017. Experimental case study of seismically induced loess liquefaction and landslide. Engineering Geology 223, 23\u201330, https:\/\/doi.org\/10.1016\/j.enggeo.2017.03.016.","DOI":"10.1016\/j.enggeo.2017.03.016"},{"key":"ref14","unstructured":"Perlea, V.G., Koester, J.P., Prakash, S. 1999. How liquefiable are cohesive soils?. Proceedings of the 2nd International Conference on Earthquake Geotechnical Engineering, Lisbon, Portugal 2, 611\u2013618."},{"key":"ref15","unstructured":"Petrova, V. 2009. Engineering geological properties of loess in the town of Silistra. Review of the Bulgarian Geological Society 70 (1\u20133), 103\u2013113 (in Bulgarian)."},{"key":"ref16","doi-asserted-by":"publisher","unstructured":"Seed, H.B., Idriss, I.M. 1971. Simplified procedure for evaluating soil liquefaction potential. Journal of Soil Mechanics and Foundations Division, American Society of Civil Engineers 97 (SM 9), 1249\u20131273, https:\/\/doi.org\/10.1061\/JSFEAQ.0001662.","DOI":"10.1061\/jsfeaq.0001662"},{"key":"ref17","doi-asserted-by":"publisher","unstructured":"Seed, H.B., Idriss, I.M., Arango, I. 1983. Evaluation of liquefaction potential using field performance data. Journal of Geotechnical Engineering 109 (3), 458\u2013482, https:\/\/doi.org\/10.1061\/(ASCE)0733-9410(1983)109:3(458).","DOI":"10.1061\/(asce)0733-9410(1983)109:3(458)"},{"key":"ref18","unstructured":"Wang, W. 1979. Some Findings in Soil Liquefaction. Water Conservancy and Hydro-electric Power Scientific Research Institute, Beijing, China, 1\u201317."},{"key":"ref19","unstructured":"Wang, W. 1984. Earthquake damages to Earth dams and levees in relation to soil liquefaction. Proceedings of the International Conference on Case Histories in Geotechnical Engineering, University of Missouri \u2013 Rolla, MO, 512\u2013522."},{"key":"ref20","unstructured":"Wang, L., Wang, Y., Wang, J., Li, L., Yuan, Z. 2004. The liquefaction potential of loess in China and its prevention. Proceedings of the 13th World Conference on Earthquake Engineering, Vancouver, B.C., Canada, August 1\u20136, Paper No. 3462."},{"key":"ref21","doi-asserted-by":"crossref","unstructured":"Wang, J., Yuan, Z., Li, L. 2007. Study on liquefaction of loess site. Proceedings of the 4th International Conference on Earthquake Geotechnical Engineering, Thessaloniki, Greece, March 25\u201328, https:\/\/doi.org\/10.1007\/s11803-002-0007-z.","DOI":"10.1007\/s11803-002-0007-z"},{"key":"ref22","doi-asserted-by":"publisher","unstructured":"Wang, G., Zhang, D., Furuya, G., Yang, J. 2014. Pore-pressure generation and fluidization in a loess landslide triggered by the 1920 Haiyuan earthquake, China: a case study. Engineering Geology 174, 36\u201345, https:\/\/doi.org\/10.1016\/j.enggeo.2014.03.006.","DOI":"10.1016\/j.enggeo.2014.03.006"},{"key":"ref23","unstructured":"Youd, T.L., Idriss, I.M. (Eds). 1997. Proceedings of the NCEER Workshop on Evaluation of Liquefaction Resistance of Soils. Technical report NCEER-97-0022. National Center for Earthquake Engineering Research, 276 pp."},{"key":"ref24","doi-asserted-by":"publisher","unstructured":"Youd, T.L., Idriss, I.M., Andrus, R.D., Arango, I., Castro, G., Christian, J.T., Dobry, R., Finn, W.D.L., Harder, L.F., Hynes, M.E., Ishihara, K., Koester, J.P., Liao, S.S.C., Marcuson, W.F., Martin, G.R., Mitchell, J.K., Moriwaki, Y., Power, M.S., Robertson, P.K., Seed R.B., Stokoe, K.H. 2001. Liquefaction resistance of soils: Summary report from the 1996 NCEER and 1998 NCEER\/NSF workshops on evaluation of liquefaction resistance of soils. Journal of Geotechnical and Geoenvironmental Engineering, 127 (10), 817\u2013833, http:\/\/dx.doi.org\/10.1061\/(ASCE)1090-0241(2001)127:10(817)","DOI":"10.1061\/(asce)1090-0241(2001)127:10(817)"}],"container-title":["Geologica Balcanica"],"original-title":[],"language":"en","deposited":{"date-parts":[[2021,4,16]],"date-time":"2021-04-16T15:45:48Z","timestamp":1618587948000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.geologica-balcanica.eu\/journal\/50\/1\/pp.-37-44"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2021,4]]},"references-count":25,"journal-issue":{"issue":"1","published-print":{"date-parts":[[2021,4]]}},"URL":"https:\/\/doi.org\/10.52321\/geolbalc.50.1.37","relation":{},"ISSN":["2535-1060","0324-0894"],"issn-type":[{"value":"2535-1060","type":"electronic"},{"value":"0324-0894","type":"print"}],"subject":[],"published":{"date-parts":[[2021,4]]}}}