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2018 Vol.34, Issue 9

Research Article

Liquefaction Resistance of Pohang Sand

포항모래의 액상화 저항 특성에 관한 연구

Sung-Sik Park1
,
Zhenzhen Nong2
,
Sun-Gyu Choi3
,
Hong-Duk Moon4*
박 성식1
,
농 쩐쩐2
,
최 선규3
,
문 홍득4*
1Member, Associate Prof., Dept. of Civil Engrg., Kyungpook National Univ.
2Graduate Student, Dept. of Civil Engrg., Kyungpook National Univ.
3Post-doctoral Researcher, Dept. of Civil and Environ. Engrg., KAIST
4Member, Prof., Dept. of Civil Engrg., Gyeongnam National Univ. of Science and Technology
1정회원, 경북대학교 공과대학 건설환경에너지공학부 부교수
2비회원, 경북대학교 공과대학 건설환경에너지공학부 박사과정
3비회원, 한국과학기술원 건설및환경공학과 박사후연구원
4정회원, 경남과학기술대학교 건설환경공과대학 토목공학과 교수
* Corresponding Author
30 September 2018. pp. 5-17
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Abstract

A magnitude 5.4 earthquake struck the city of Pohang, North Gyeongsang Province, South Korea on November 15, 2017. Many sand volcanoes were observed on paddy fields, parks and roads. This phenomenon was the first to be observed as a sign of soil liquefaction in South Korea. In this study, two different kinds of ejected Pohang sands were collected from a liquefied paddy field. Those sands were reconstituted into loose and dense conditions and then a series of cyclic simple shear tests were conducted under confining stresses of 100 and 200 kPa. A real earthquake motion was also repetitively applied to the specimen. As a result of constant shear stress tests, the cyclic resistance ratio (CRR) of loose sand was 0.12-0.14, while the CRR value of dense sand was 0.17-0.21. It was shown that the relative density was more influencing factor on liquefaction resistance than the sand types and initial confining stress. When a real Pohang earthquake motion was repetitively applied to the specimen, a loose sand was liquefied at the second earthquake motion but the dense sand at the third earthquake motion.

Keywords
Liquefaction
Sand
Pohang earthquake
Direct simple shear test

2017년 11월 15일 경상북도 포항시 흥해읍에서 5.4 규모의 지진으로 논, 공원 또는 도로 등지에서 액상화로 인해 모래와 물이 지표면으로 분출되는 현상이 국내에서 처음으로 발생하였다. 본 연구에서는 포항지역 논에서 분출한 모래를 채취한 다음, 이를 2 종류로 분류하여 이에 대한 반복직접단순전단시험을 실시하였다. 포항모래의 상대밀도에 따른 액상화 거동을 연구하기 위해 느슨하거나 조밀한 상태로 모래를 재성형한 다음 구속응력 100kPa 또는 200kPa를 가한 후 정현파의 반복전단응력을 가하였다. 또한 실제 포항지역에서 계측된 지진파를 실험기기에 입력하여 액상화 발생 여부를 연구하였다. 정현파를 사용한 전단시험 결과 느슨한 시료의 전단저항응력비는 0.12-0.14, 조밀한 시료는 0.17-0.21정도로 조밀한 모래의 액상화 저항력이 느슨한 상태보다 42-50% 정도 높게 나타났다. 모래 종류 및 구속응력보다는 모래의 상대밀도가 액상화 저항력에 더 큰 영향을 미치는 것으로 나타났다. 실지진파를 이용한 전단시험 결과는 구속응력에 관계없이 느슨한 모래의 경우는 2회, 조밀한 모래는 3회 정도의 반복입력 시 액상화가 발생하는 것으로 나타났다.

References
1
Bjerrum, L. and Landva, A. (1966), “Direct simple shear tests on a Norwegian quick clay”, Geotechnique, Vol.16, No.1, pp.1-20.
https://doi.org/10.1680/geot.1966.16.1.1
2
Darendeli, M. B. (2001), Development of a new family of normalized modulus reduction and material damping curves, Ph.D. Dissertation, the University of Texas at Austin, America.
3
EduPro (2006), ProShake, Version 1.12, EduPro Civil Systems. Inc.
4
Finn, W.L, Ledbetter, R.H., and Wu, G. (1994), “Liquefaction in silty soils: design and analysis. Ground Failure under Seismic conditions”, Geotechnical Special Publication, No.44, pp.51-76.
5
Hazirbaba, K. and Rathje, E. (2004), “A comparison between in situ and laboratory measurements of pore water pressure generation”, Proc. 13th World Conference on Earthquake Engineering, Vancouver, Canada.
6
Idriss, I. M. (1991), Procedures for selecting earthquake ground motions at rocks sites. Report prepared for the Structures Division, Building and Fire Research Laboratory, National Institute of Standards and Technology. Center for Geotechnical Modeling, Department of Civil & Environmental Engineering, University of California, Davis.
7
Jiang, M., Cai, Z. Y., Cao, P., and Liu, D. (2010), “Effect of cyclic loading frequency on dynamic properties of marine clay”, GeoShanghai 2010 International Conference, Shanghai, China, pp. 240-245.
https://doi.org/10.1061/41101(374)36
8
JIS A 1224:2000, Test Method for Minimum and Maximum Densities of Land, Japanese Standards Association.
9
Kim, S. J. (2009), Behavior of sand in cyclic simple shear test, Master Thesis, Busan National University, South Korea.
10
Koester, J.P. (1994), “The influence of fine type and content on cyclic strength. Ground Failure under Seismic conditions”, Geotechnical Special Publication, No.44, pp.17-33.
11
Kammerer, A., Wu, J., Pestana, J., Riemer, M., and Seed, R. (2000), “Cyclic simple shear testing of Nevada sand for PEER Center project 2051999”, Geotechnical Engineering Research Report UCB/GT/00-01, University of California, Berkeley, Calif.
12
Ladd, R. S. (1978), “Preparing test specimens using under compaction”, Geotechnical Testing Journal, Vol.1, No.1, pp.16-23.
https://doi.org/10.1520/GTJ10364J
13
Law, K.T. and Ling, Y.H. (1992), “Liquefaction of granular soils with non-cohesive and cohesive fines”, Proceedings of the 10th World Conference on Earthquake Engineering, Rotterdam, pp.1491-1496.
14
Lee, C. J., Kim, S.I., and Jeong, S. S. (2010), “A study on the liquefaction resistance of anisotropic sample under real earthquake loading”, Journal of the Korean geotechnical society, Vol.26, No. 2, pp.5-14.
15
Mandokhail, S. J., Park D., Kim, H., and Park, K. C. (2016), “Cyclic simple shear test based design liquefaction resistance curve of granular soil”, Journal of the Korean geotechnical society, Vol. 32, No.6, pp.49-59.
https://doi.org/10.7843/kgs.2016.32.6.49
16
National Disaster Management Research Institute (2017), The investigated result of liquefaction due to Pohang earthquake (2017.11.15).
17
Park, S. S., Kim, Y. S., and Kim, S. H. (2011), “Cyclic shear characteristics of Nakdong River Sand containing fines with varying plasticity”, KSCE Journal of Civil Engineering, Vol.31, No.3C, pp.93-102.
18
Seed, H.B., Idriss, I. M., and Arango, I. (1983), “Evaluation of liquefaction potential using field performance data”, Journal of Geotechnical Engineering Division, Vol.109, No.3, pp.458-482.
https://doi.org/10.1061/(ASCE)0733-9410(1983)109:3(458)
19
Seed, H.B., Martin, P.P., and Lysmer, J. (1976), “Pore-water pressure changes during soil liquefaction”, Journal of the Geotechnical Engineering Division, Vol.102, No.GT4, pp.323-346.
20
Seed, H.B., Tokimatsu, K., Harder, L.F., and Chung, R.M. (1985), “The influence of SPT procedures in soil liquefaction resistance evaluations”, Journal of Geotechnical Engineering, Vol. 111, No.12, pp.1425-1445.
https://doi.org/10.1061/(ASCE)0733-9410(1985)111:12(1425)
21
Seed, H.B., Wong, R.T., Idriss, I.M., and Tokimatsu, K. (1986), Moduli and damping factors for dynamic analyses of cohesionless soils, Journal of Geotechnical Engineering, Vol.112, No.11, pp. 1016-1032.
https://doi.org/10.1061/(ASCE)0733-9410(1986)112:11(1016)
22
Sitharam, T. G. and Govindaraju, L. (2007), “Pore pressure generation in silty sands during cyclic loading”, Geotechnics and Geoengineering, Vol.2, No.4, pp.295-306.
https://doi.org/10.1080/17486020701670460
23
Sim, J. U., Choi, J. S., and Jim, S. I. (2002), “An experimental study for the liquefaction resistance strength of saturated using real earthquake loading”, Journal of the Korean geotechnical society, Vol.18, No.2, pp.329-337.
24
Skempton, A. W. (1986), “Standard Penetration Test Procedures and the effects in Sands of Overburden Pressure, Relative Density, Particle Size, Ageing and Over Consolidation”, Geotechnique, No.36, pp.425-447.
https://doi.org/10.1680/geot.1986.36.3.425
25
Sriskandakumar, S. (2004), Cyclic Loading Response of Fraser River Sand for Validation of Numerical Models Simulating Centrifuge Tests, M.A.Sc. Thesis, University of British Columbia.
26
Vaid, Y.P. (1994), “Liquefaction of silty soils. Ground Failure under Seismic conditions”, Geotechnical Special Publication, No. 44, pp.1-16.
27
Vaid, Y. P. and Sivathayalan, S. (1996), “Static and cyclic liquefaction potential of Fraser Delta sand in simple shear and triaxial tests”, Canadian Geotechnical Journal, Vol.33, No.2, pp.281-289.
https://doi.org/10.1139/t96-007
28
Viana, A. D. F., Soares, M., and Fourie, A. B. (2015), “Cyclic DSS tests for the evaluation of stress densification effects in liquefaction assessment”, Soil Dynamics and Earthquake Engineering, 75, pp. 98-111.
https://doi.org/10.1016/j.soildyn.2015.03.016
29
Yoon, Y. W., Yoon, G. L., and Choi, J. K. (2007), “Liquefaction strength of shelly sand in cyclic simple shear test”, Journal of the Korean Geo-Environmental Society, Vol.8, No.6, pp.69-76.
30
Youd, T. L., Idriss, I. M., Andrus, R. D., Arango, I., Castro, G, Christian, J. T., Dobry, R., Finn, W. D. L., Harder Jr., L. F., Hynes, M. E., Ishihara, K., Koester, J. P., Liao, S., Marcuson Ш, W. F., Martin, G. R., Mitchell, J. K., Moriwaki, Y., Power, M. S., Robertson, P. K., Seed, R. B., and 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, Vol.127, No.10, pp.817-833.
https://doi.org/10.1061/(ASCE)1090-0241(2001)127:10(817)
31
Zlatovic, S. and Ishihara, K. (1997), “Normalized behavior of very loose non-plastic soils: effects of fabric”, Soils and Foundations, Vol.37, No.4, pp.47-56.
https://doi.org/10.3208/sandf.37.4_47
Information
  • Publisher :The Korean Geotechnical Society
  • Publisher(Ko) :한국지반공학회
  • Journal Title :Journal of the Korean Geotechnical Society
  • Journal Title(Ko) :한국지반공학회 논문집
  • Volume : 34
  • No :9
  • Pages :5-17
  • Received Date : 2018-06-12
  • Revised Date : 2018-08-12
  • Accepted Date : 2018-08-20
  • DOI :https://doi.org/10.7843/kgs.2018.34.9.5
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