Comparison of liquefaction evaluation based on SPT and geophysical tests (case study: Mahabad dam, Iran)

Shahrabi, M. M ; Sharif University of Technology

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  1. Type of Document: Article
  2. Publisher: Australian Geomechanics Society
  3. Abstract:
  4. Standard Penetration Test (SPT) is the most commonly used insitu test for soil characterization, including the liquefaction resistance. Many studies have sought to correlate SPT number to cyclic resistance ratio (CRR) as a frequently-used approach for assessment of liquefaction potential. However, it has been shown that SPT has major deficiencies (e.g., inaccuracy in coarse sands and clays) which have given rise to development and utilization of new characterization methods such as geophysical tests (e.g., down-hole and cross-hole). In this paper, a comparison is made between the results of SPT and geophysical tests in three boreholes through the body and foundation of Mahabad Dam (located in north-western part of Iran) and the corresponding assessment of liquefaction potential. It is shown that the cyclic resistance stresses obtained by SPT are lower than those obtained by geophysical tests. Hence, some parts of the dam body are found close to being liquefiable by means of SPT tests, whereas geophysical tests prove the dam site to be safer, indicating considerable discrepancy between the two methods. Additionally, for some parts of the dam body and especially dam foundation where confining pressures are high or the soil is very dense and SPT number (N) is not an applicable characterization measure, shear wave velocities obtained by geophysical tests provide a meaningful tool for assessment of liquefaction potential
  5. Keywords:
  6. Characterization ; Dams ; Shear flow ; Shear waves ; Soil liquefaction ; Assessment of liquefactions ; Characterization methods ; Confining pressures ; Development and utilizations ; Liquefaction evaluation ; Liquefaction resistance ; Soil characterization ; Standard penetration test ; Geophysics
  7. Source: 5th International Conference on Geotechnical and Geophysical Site Characterisation, 5 September 2016 through 9 September 2016 ; Volume 1 , 2016 , Pages 657-661 ; 9780994626110 (ISBN)
  8. URL: https://www.scopus.com/inward/record.uri?eid=2-s2.0-85015184452&partnerID=40&md5=0b49348f17dc9581d346491d05ea2a55