Evaluating liquefaction potential of pumiceous deposits through field testing
Case study of the 1987 Edgecumbe earthquake
DOI:
https://doi.org/10.5459/bnzsee.53.2.101-110Abstract
Pumice materials, which are problematic from an engineering viewpoint, are widespread in the central part of the North Island. Considering the impacts of the 2010-2011 Christchurch earthquakes, a clear understanding of their properties under earthquake loading is necessary. For example, the 1987 Edgecumbe earthquake showed evidence of localised liquefaction of sands of volcanic origin. To elucidate on this, research was undertaken to investigate whether existing empirical field-based methods to evaluate the liquefaction potential of sands, which were originally developed for hard-grained soils, are applicable to crushable pumice-rich deposits. For this purpose, two sites, one in Whakatane and another in Edgecumbe, were selected where the occurrence of liquefaction was reported following the Edgecumbe earthquake. Manifestations of soil liquefaction, such as sand boils and ejected materials, have been reported at both sites. Field tests, including cone penetration tests (CPT), shear-wave velocity profiling, and screw driving sounding (SDS) tests were performed at the sites. Then, considering estimated peak ground accelerations (PGAs) at the sites based on recorded motions and possible range of ground water table locations, liquefaction analysis was conducted at the sites using available empirical approaches. To clarify the results of the analysis, undisturbed soil samples were obtained at both sites to investigate the laboratory-derived cyclic resistance ratios and to compare with the field-estimated values. Research results clearly showed that these pumice-rich soils do not fit existing liquefaction assessment frameworks and alternate methods are necessary to characterise them.
References
Pender MJ and Robertson TW, eds. (1987). “Edgecumbe Earthquake: Reconnaissance Report”. Bulletin of the New Zealand National Society for Earthquake Engineering, 20 (3): 201-249. DOI: https://doi.org/10.5459/bnzsee.20.3.201-249
Wesley LD, Meyer VM, Pronjoto S, Pender MJ, Larkin TJ and Duske GC (1999). “Engineering properties of pumice sand”. Proc., 8th Australia-NZ Conference on Geomechanics, Hobart, 2: 901 – 908.
Orense RP, Pender MJ and O’Sullivan A (2012). “Liquefaction Characteristics of Pumice Sands”. Final Report of EQC Project 10/589, 131pp.
Orense RP and Pender MJ (2013). “Liquefaction characteristics of crushable pumice sand”. Proc. 18th International Conference on Soil Mechanics and Geotechnical Engineering, Paris, 4pp.
Orense RP, Mirjafari Y and Suemasa N (2019). “Screw Driving Sounding: A new test for field characterisation”. Geotechnical Research, 6(1): 28–38. DOI: https://doi.org/10.1680/jgere.18.00024
Mirjafari Y, Orense RP and Suemasa N (2016). “Soil classification and liquefaction evaluation using Screw Driving Sounding”. Proc., 5th International Conference on Geotechnical and Geophysical site Characterisation, Gold Coast, Australia, 6pp.
Boulanger RW and Idriss IM (2014). “CPT and SPT based Liquefaction Triggering Procedures”. Report No. UCD/CGM-14/01, Center for Geotechnical Modeling, Department of Civil and Environmental Engineering, University of California, Davis, CA, 134 pp.
Robertson PK and Cabal KL (2012). Guide to Cone Penetration Testing for Geotechnical Engineering, 5th Edition, Gregg Drilling & Testing, 131pp.
Moss RES, Seed RB, Kayen RE, Stewart JP, Der Kiureghian A and Cetin KO (2006). “CPT-based probabilistic and deterministic assessment of in situ seismic soil liquefaction potential”. Journal of Geotechnical and Geo-environmental Engineering, 132(8): 1032-1051. DOI: https://doi.org/10.1061/(ASCE)1090-0241(2006)132:8(1032)
Andrus RD and Stokoe KH II (2000). “Liquefaction resistance of soils from shear-wave velocity”. Journal of Geotechnical and Geo-environmental Engineering, 126(11): 1015–1025. DOI: https://doi.org/10.1061/(ASCE)1090-0241(2000)126:11(1015)
Kayen RE, Moss RES, Thompson EM, Seed RB, Cetin KO, Der Kiureghian A, Tanaka Y and Tokimatsu K (2013). “Shear-wave velocity–based probabilistic and deterministic assessment of seismic soil liquefaction potential”. Journal of Geotechnical and Geo-environmental Engineering, 139(3): 407-419. DOI: https://doi.org/10.1061/(ASCE)GT.1943-5606.0000743
Mellsop N (2017). “Liquefaction Case Histories from the 1987 Edgecumbe Earthquake –Insights from an Extensive CPT Dataset, Direct Push Cross Hole Shear and Compression Wave Velocity (VsVp) Testing and Paleo-Liquefaction Trenching”. ME Thesis, University of Auckland.
Iwasaki T, Tokida K, Tatsuoka F and Yasuda S (1978). “A practical method for assessing soil liquefaction potential based on case studies at various sites in Japan”. Proc. 2nd International Conference on Microzonation, San Francisco, 885–896.
Tonkin & Taylor (2013). “Liquefaction Vulnerability Study”. Report Submitted to the Earthquake Commission, February 2013 Ref 52020.0200 v1.0.
Mori K and Sakai K (2016). “The GP sampler: a new innovation in core sampling”. Journal of the Australian Geomechanics Society, 51(4): 131-166.
Stringer ME, Orense RP, Pender MJ and Haycock I (2018). “Undisturbed sampling of pumiceous deposits in New Zealand”. Proc. Geotechnical Earthquake Engineering and Soil Dynamics V (GSP 293), Austin, Texas, 394-403. DOI: https://doi.org/10.1061/9780784481486.041
Stringer ME, Asadi MB, Orense RP, Asadi MS and Pender MJ (2019). “Cyclic behavior of undisturbed samples from pumice-rich soils”. Proc., 7th International Conference on Earthquake Geotechnical Engineering, Rome, Italy, 5112-5119.
Ishihara K (1985). “Stability of natural deposits during earthquakes”. Proc., 11th International Conference on Soil Mechanics & Foundation Engineering, San Francisco, CA, 1: 321-376.
Towhata I (2008). Geotechnical Earthquake Engineering. Springer Science & Business Media, Berlin. DOI: https://doi.org/10.1007/978-3-540-35783-4
Asadi MB, Asadi MS, Orense RP and Pender MJ (2018). “Shear wave velocity-based assessment of liquefaction resistance of natural pumiceous sands”. Géotechnique Letters, 8(4): 1-6. DOI: https://doi.org/10.1680/jgele.18.00102
