터널과지하공간 (Tunnel and Underground Space)

  • 제28권6호
  • /
  • Pages.635-650
  • /
  • 2018
  • /
  • 1225-1275(pISSN)
  • /
  • 2287-1748(eISSN)
한국암반공학회 (Korean Society for Rock Mechanics and Rock Engineering)
권호 표지
DOI QR코드

DOI QR Code

수치해석을 통한 지진하중의 주기특성에 따른 그라운드 앵커의 거동

Behaviour of Ground Anchor According to Period Characteristic of Seismic Load Using Numerical Analysis

  • 오동욱 (서울과학기술대학교 건설시스템공학과) ;
  • 정혁상 (동양대학교 철도대학 철도건설안전공학과) ;
  • 윤환희 (동양대학교 일반대학원 철도토목학과) ;
  • 이용주 (서울과학기술대학교 건설시스템공학과)
  • Oh, Dong-Wook (Department of Civil Engineering, Seoul National University of Science and Technology) ;
  • Jung, Hyuk-Sang (Department of Railroad Construction and Safety Engineering, Dongyang University) ;
  • Yoon, Hwan-Hee (Department of Railroad and Civil Engineering, Dongyang University) ;
  • Lee, Yong-Joo (Department of Civil Engineering, Seoul National University of Science and Technology)
  • 투고 : 2018.11.29
  • 심사 : 2018.12.24
  • 발행 : 2018.12.31
PDF 다운로드
⟨ 이전 논문 다음 논문 ⟩

초록

최근 국내에 발생된 지진으로 인해 더 이상 한반도가 지진으로부터 안전지대가 아니라는 것이 많은 사람들에게 각인되었다. 경주와 포항에서 발생된 지진은 그 동안 국내에서 내진설계에 기준으로 고려한 지진의 특성과 상이하게 나타났고, 그에 따른 내진설계 방법에 대한 연구 또한 많은 연구자들에 의해 수행되어 지고 있다. 이러한 지진하중에 대한 고려는 주로 기존 상부 구조물에 초점이 맞춰져 있으며, 그에 따른 연구 또한 활발히 이루어지고 있는 실정이다. 하지만, 지반의 구조적 안정성을 확보하기 위해 시공된 네일, 록볼트, 그라운드 앵커 등과 같은 지중구조물에 대한 지진하중으로부터의 구조적 안정성에 대한 고려는 많이 이루어지지 않고 있는 실정이다. 본 연구에서는 풍화암에 정착된 그라운드 앵커에 대해 정하중이 작용할 때와 지진하중이 앵커에 미치는 영향을 분석하였다. 정하중에 의한 영향은 현장 인장시험 결과로, 지진하중 영향은 수치해석을 통해 파악하였다. 그 결과, 앵커에 긴장력 도입으로 인한 반력판의 침하가 발생하는 것으로 나타났으며, 그로 인한 앵커의 축력 감소가 발생하였다. 또한 지진하중에 의해 앵커 정착부의 변위가 증가하였으며, 정착부 길이가 길수록 장주기 지진에 의한 영향이 큰 것으로 나타났다.

Many people have been recognized that the Korean Peninsula is no longer safe area from the earthquake by the recent earthquakes occurred in the country. The earthquakes that occurred at Pohang and Gyeongju appeared differently from them considered in the seismic design and researches on the seismic design method have been also conducted by many researchers. Studies on seismic loads are mainly focused on existing superstructures, and research involving them has been actively carried out in reality. However, paper regarding structural stability of reinforcement from seismic load such as soil-nails, rock-bolts, ground anchors which were constructed to ensure stability of serviced structure have been published rarely. In this study, ground anchor been effected by static load and seismic load which is settled in the weathered rock is analyzed. Results for static load are obtained from field test and seismic load is from numerical analysis. In this study, the behavioral characteristics of the ground anchor were analyzed by numerical analysis in case of seismic loading based on the result of the in-situ tensile test of the ground anchor settled weathered rock. As a result, settlement of concrete block due to application of tension force for ground anchor occurred as well as following loss of axial force for ground anchor. Also, as bond length and period of seismic load are longer, increasement of displacement is greater.

키워드

OBGHBQ_2018_v28n6_635_f0001.png 이미지

Fig. 1. N value with depth

OBGHBQ_2018_v28n6_635_f0002.png 이미지

Fig. 2. Ground anchor construction phase

OBGHBQ_2018_v28n6_635_f0003.png 이미지

Fig. 3. Result and overview of performance test for ground anchor

OBGHBQ_2018_v28n6_635_f0004.png 이미지

Fig. 4. Earthquake wave propagation

OBGHBQ_2018_v28n6_635_f0005.png 이미지

Fig. 5. Mesh generation for numerical analysis

OBGHBQ_2018_v28n6_635_f0006.png 이미지

Fig. 6. Dynamic curve

OBGHBQ_2018_v28n6_635_f0007.png 이미지

Fig. 7. Settlement of concrete block

OBGHBQ_2018_v28n6_635_f0008.png 이미지

Fig. 8. δv for T step depending on Lb

OBGHBQ_2018_v28n6_635_f0009.png 이미지

Fig. 9. Increasement vertical displacement (Δδv)

OBGHBQ_2018_v28n6_635_f0010.png 이미지

Fig. 10. Vertical displacement rate of change

OBGHBQ_2018_v28n6_635_f0011.png 이미지

Fig. 11. Normalized δv rate of change

OBGHBQ_2018_v28n6_635_f0012.png 이미지

Fig. 12. δH of bond length

OBGHBQ_2018_v28n6_635_f0013.png 이미지

Fig. 13. Change of axial force due to earthquake

Table 1. Material properties

OBGHBQ_2018_v28n6_635_t0001.png 이미지

Table 2. Rayleigh damping coefficient

OBGHBQ_2018_v28n6_635_t0002.png 이미지

참고문헌

  1. Lee, G.Y. and Oh, C.W., 2017, 5 reasons the damage from Pohang earthquake bigger than Gyeongju earthquake, Hankyoreh, 2017.11.17.
  2. Amorosi, A. and Boldini, D., 2009, Numerical modelling of the transverse dynamic behaviour of circular tunnels in clayey soils, Soil Dynamics and Earthquake Engineering, Vol 2009, 1059-1072.
  3. George, D.H. and Dimitri, E.B., 2010, Soil-structure interaction effects on seismic inealstic analysis of 3-D tunnels, Soil Dynamics and Earthquake Engineering, Vol 2010, 851-861.
  4. Geotechnical Control Office, 1997, Model Specification for Prestressed Ground Anchors, Civil Engineering Department Hong Kong, Geospec 1, 1-164.
  5. Yu, H., Yuan, Y., Qiao, Z., Gu, Y., Yang, Z. and Li, X., 2013, Seismic analysis of a long tunnel based on multi-scale method, Engineering Structure, Vol 2013, 572-587.
  6. Lee, D.H., Shim, J.Y. and Jeon, J.S., 2016, Damage Potential of a Domestic Metropolitan Railway Bridge subjected to 2016 Gyeonju Earthquake, EESK J Earthquake Eng, Vol 20, No 7, 461-472
  7. Koseki, J., Koda, M., Matsuo, S., Takasaki, H. and Fujiwara, T., 2012, Damage to railway earth structures and foundations caused by the 2011 off the Pacific Coast of Tohoku Earthquake, Vol 52, No 5, 872-889. https://doi.org/10.1016/j.sandf.2012.11.009
  8. Ha, S.J., Han, S.W. and Oh, J.H., 2017, Assessment of Code-specified Ground Motion Selection Criteria with Accurate Selection and Scaling Method-II Seismic Response, EESK J Earthquake Eng, Vol 21, No 4, 181-188. https://doi.org/10.1080/13632469.2016.1160008
  9. You, K.H. and Kim, Y.J., 2018, A preliminary numerical analysis study on the seismic stability of a building and underground structure by using SSI, Journal of Korean Tunnelling and Underground Space Association, Vol 20, No 1, 23-38. https://doi.org/10.9711/KTAJ.2018.20.1.023
  10. Ministry of Land, 2009, Ground Anchor Design.Construction and Maintenance Manual, Ministry of Land, 1-160.
  11. Park, D.H., Shin, J.H. and Yun, S.U., 2010, Seismic Analysis of Tunnel in Transverse Direction Part II: Evaluation of Seismic Tunnel Response via Dynamic Analysis, Journal of the Korean Geotechnical Society, Vol 26, No 6, 71-85.
  12. Plaxis bv, 2018, Reference Manual, Plaxis bv, 1-494.
  13. Song, K.I., Cho, G.C. and Chang, S.B., 2008, Evaluation of bonding state of tunnel shotcrete using impact-echo method - numerical analysis, Tunnelling Technology, Vol 10, No 2, 105-118.
  14. Yoon, J.K., Kim, D.S. and Bang, E.S., 2006, Journal of the Earthquake Engineering Society of Korea, Vol 10, No 2, 51-62.
  15. Hashash, Y.M.A., Musgrove, M.I., Harmon, J.A., Okan, I., Groholski, D.R., Phillips, C.A., and Park, D., 2017, Deepsoil 7.0, User Manual, 1-169.