Journal of the Korean GEO-environmental Society (한국지반환경공학회 논문집)

Korean Geo-Environmental Society (한국지반환경공학회)
권호 표지
DOI QR코드

DOI QR Code

Correlations of Earthquake Accelerations and LPIs for Liquefaction Risk Mapping in Seoul & Gyeonggi-do Area based on Artificial Scenarios

서울, 경기지역의 시나리오별 액상화 위험지도 작성을 위한 지진가속도와 LPI 상관관계 분석

  • Received : 2019.01.18
  • Accepted : 2019.03.28
  • Published : 2019.05.01
Download PDF
⟨ Previous Next ⟩

Abstract

On November 15, 2017, a unpredictable liquefaction damage was occurred at the $M_L=5.4$ Pohang earthquake and after, many researches have been conducted in Korea. In Korea, where there were no cases of earthquake damage, it has been extremely neglectable in preparing earthquake risk maps and building earthquake systems that corresponded to prevention and preparation. Since it is almost impossible to observe signs and symptoms of drought, floods, and typhoons in advance, it is very effective to predict the impacts and magnitudes of seismic events. In this study, 14,040 borehole data were collected in the metropolitan area and liquefaction evaluation was performed using the amplification factor. Based on this data, liquefaction hazard maps were prepared for ground accelerations of 0.06 g, 0.14 g, 0.22 g, and 0.30 g, including 200years return period to 4,800years return period. Also, the correlation analysis between the earthquake acceleration and LPI was carried out to draw a real-time predictable liquefaction hazard map. As a result, 707 correlation equations in every cells in GIS map were proposed. Finally, the simulation for liquefaction risk mapping against artificial earthquake was performed in the metropolitan area using the proposed correlation equations.

2017년 11월 15일 발생한 $M_L=5.4$의 포항지진으로 액상화 피해사례가 접수되었으며 이에 대한 많은 연구가 수행 중에 있다. 지진에 의한 피해사례가 전무하였던 우리나라의 경우, 예방 및 대비에 해당하는 지진위험지도 작성과 지진 및 지진해일 관측시스템의 구축에 매우 소극적이었다. 지진은 가뭄, 홍수나 태풍 등과 달리, 발생 징후를 관찰하고 그 영향 및 규모를 미리 예측하기란 거의 불가능에 가깝기 때문에 예방 및 대비차원의 액상화 위험지도와 같은 지진재해지도 구축은 매우 효과적일 수 있다. 본 연구는 수도권지역 14,040개의 시추공 데이터를 수집하여 지반증폭계수를 이용한 액상화 평가를 우선적으로 실시하고 최대기반암가속도는 재현주기 200년부터 4,800년을 포함하는 최대기반암가속도 0.06g, 0.14g, 0.22g, 0.30g에 대한 액상화 위험지도를 작성하였다. 또한, 실시간 예측 가능한 액상화 위험지도 작성을 위해 지진가속도와 상관관계 분석을 실시하였으며 그 결과로 수치지도의 모든 셀에 해당하는 상관식이 제안되었다. 최종적으로 제안된 상관식을 이용하여 가상의 지진에 대한 액상화 위험지도를 작성하였다.

Keywords

HJHGC7_2019_v20n5_5_f0001.png 이미지

Fig. 1. Liquefaction map of christchurch (new zealand EQC, 2015)

HJHGC7_2019_v20n5_5_f0002.png 이미지

Fig. 2. Liquefaction hazard map for northwestern alameda country(www.usgs.gov)

HJHGC7_2019_v20n5_5_f0003.png 이미지

Fig. 3. Liquefaction map of seoul (Kwak et al., 2015)

HJHGC7_2019_v20n5_5_f0004.png 이미지

Fig. 4. Flow chart of calculation LPI

HJHGC7_2019_v20n5_5_f0005.png 이미지

Fig. 5. Evaluating liquefaction program (Baek, 2014)

HJHGC7_2019_v20n5_5_f0006.png 이미지

Fig. 6. Borehole locations in seoul, gyeongggi, incheon city

HJHGC7_2019_v20n5_5_f0007.png 이미지

Fig. 7. Liquefaction risk map using visual basic program

HJHGC7_2019_v20n5_5_f0008.png 이미지

Fig. 8. Seismic intensity distribution map (www.usgs.gov)

HJHGC7_2019_v20n5_5_f0009.png 이미지

Fig. 9. Coefficient of determination graph

HJHGC7_2019_v20n5_5_f0010.png 이미지

Fig. 10. Simulation pga map at hongseong ML6.0

HJHGC7_2019_v20n5_5_f0011.png 이미지

Fig. 11. Simulation liquefaction risk map at hongseong ML6.0

Table 1. Amplification coefficient according to soil type of South Korea & euro-code (Ministry of Construction and Transportation, seismic design criteria II 1997; European Committee for standardization, 1998)

HJHGC7_2019_v20n5_5_t0001.png 이미지

Table 2. Priority analysis of function

HJHGC7_2019_v20n5_5_t0002.png 이미지

Table 3. Priority analysis of hyperbolic & logarithm function

HJHGC7_2019_v20n5_5_t0003.png 이미지

References

  1. Ahn, J. K., Baek, W. H., Choi, J. S. and Kawk, D. Y. (2018), Investigation of Pohang earthquake liquefaction using 1D effective-stress site response analysis, Journal of the Korean Geotechnical Society, Vol. 34, No. 9, Agust, pp. 37-49.
  2. Baek, W. H. (2014), "Development of Real-Time Liquefaction Hazard map using Metropolitan area site information data", University of Seokyeong, Seoul, Korea (In Korean).
  3. Baek, W. H., Choi, J. S. and Ahn, J. K. (2018), "Seismic scenarios-based liquefaction hazard map for Pohang area", EESK J Earthquake Eng., Vol. 22, No. 3, pp. 219-224 (In Korean).
  4. Baek W. H., Choi J. S. and Kwon O. G. (2015), Real time earthquake hazard map of liquefaction in Korea, The 15th Asian Regional Conferenceon Soil Mechanics and Geotechnical Engineering, 2015/11, Fukuoka, Japan.
  5. Choi, J. S., Kwon, O. G. and Baek, W. H. (2014), Macro liquefaction hazard map for metropolitan areas in moderate seismic countries, 2nd Asia Conference on Urban Disaster Reduction, 2014/11, Taipei, Taiwan.
  6. European Committee for standardization (1998), Eurocode 8, Brussels, Belgium, pp. 33-35.
  7. EQC (New Zealand Earthquake Commission) (2015), Canterbury Earthquake Sequence : Increased Liquefaction Vulneralbility Assessment Methodology, Tonkin+Taylor.
  8. Idriss, I. (1999), "An update to the Seed-Idriss simplified procedure for evaluating liquefaction potential", Proc., TRB Worshop on New Approaches to Liquefaction, Pubbl. n. FHWA-RD-99-165, Federal Highway Administation.
  9. Iwasaki, T., Tatsuoka, F., Tokida, K. I. and Yasuda, S. (1978), "A practical method for assessing soil liquefaction potential based on case studies at various sites in Japan", Proc. Second Int. Conf. Microzonation Safer Construction Research Application, 1978, 2, pp. 885-896.
  10. Kim, S. I., Park., I. J. and Choi, J. S. (2000), A study on the assessment of liquefaction potential in Korea, Journal of Korean Society of Civil Engineers, KSCE, 20(2-C), 129-139 (In Korean).
  11. Kwak, C. W. (2001), A study on the liquefaction hazard micro zonation at reclaimed ports and harbors in Korea, Master dissertation, University of Yonsei, Seoul, Korea (In Korean).
  12. Kwak, M. J., Ku, T. J. and Choi, J. S. (2015), Development of mapping method for liquefaction hazard in moderate seismic region considering the uncertainty of big site investigation Data, Journal of the Korean Geo Environmental Society, 16(1), 17-27 (In Korean).
  13. Ku, T. J. (2010), Development of mapping of liquefaction hazard considering various ground condition in Korea, Master dissertation, University of Seokyeong, Seoul, Korea (In Korean).
  14. Seed, H. B., Tokimatsu, K., Harder, L. F. and Chung, R. M. (1985), Influence of SPT procedures in soil liquefaction resistance evaluations, Journal of Geotechnical Engineering, Vol. 111, Issue. 12, pp. 1425-1445. https://doi.org/10.1061/(ASCE)0733-9410(1985)111:12(1425)
  15. Sun, C. K., Jeong, C. K. and Kim, D. S. (2005), A proposition of site coefficients and site classification system for design ground motions at inland of the Korean Peninsula, Journal of Korean Geotechnical Society, KGS, Vol. 21, No. 6, pp. 101-115 (In Korean).
  16. Ministry of Construction and Transportation, seismic design criteria II (1997) (In Korean).
  17. Ministry of Interior Safety (2017), Enforcement decree of th earthquake and volcano disaster countermeasure pp.paragraph (2) in Aticle 10 (in Korean).
  18. National Disaster Management Institute, Program Development of Seismic Hazard Map (2001), pp. 25-26.
  19. Rea, L. M. and Parker, R. A. (2005), Designing & Conducting Survey Research A Comprehensive Guide (3rd Edition). San Francisco, CA: Jossey-Bass.
  20. Seed, H. B. and Idriss, I. M. (1971), "Simplified procedure for evaluating soil liquefaction potential", Journal of the Soil Mechanics and Foundations Division, Vol. 97, No. 9, pp. 1249-1273. https://doi.org/10.1061/JSFEAQ.0001662