Seismic behaviors of twin tunnel with flexible segment

Chang-Won Kwak; Inn-Joon Park

doi:10.9711/KTAJ.2015.17.6.695

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2015 Vol.17, Issue 6 Preview Page

Seismic behaviors of twin tunnel with flexible segment Flexible Segment가 설치된 병렬터널의 지진시 동적거동

30 November 2015. pp. 695-702

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Abstract

Recently, the improvement of mechanical and theoretical issues in geo-centrifuge test enhances the applicability and accuracy of the test. Geo-centrifuge test is appropriate to simulate the behaviors of underground structures like tunnel, since tunnel interacts with the soil and/or rock around it and the test can embody the in-situ stress conditions effectively. In this study, the seismic behaviors of twin tunnel were analyzed based on geo-centrifuge test. Flexible segment to mitigate seismic acceleration were implemented in the model with thin and thick thickness. Based on the test results, it was found that flexible segment can decrease the peak acceleration generally, however, thin flexible segment was not able to reduce peak acceleration in short-period seismic wave. Thick flexible segment was more effective in case of high bedrock acceleration condition. Additionally, 3-dimensional numerical analysis was performed to verify the characteristics of seismic behavior and the effect of flexible segment. Consequently, the numerical analysis result showed good agreement with the test result.

Keywords

Geo-centrifuge

Twin tunnel

Flexible segment

Numerical analysis

원심모형시험은 최근의 기계적, 이론적 발전에 따라 그 활용도와 정확성이 높아지고 있다. 원심모형시험은 원지반 응력을 효과적으로 재현할 수 있으므로 주위 지반 또는 암반과 상호작용을 하는 터널과 같은 지하구조물의 거동을 모사하기 적합하다. 본 연구에서는 병렬 터널의 지진시 동적 거동을 원심모형시험을 통하여 분석하였다. 터널 모델링시 지진에 의해 발생하는 최대 가속도 저감을 위하여 Flexible segment를 고려하였으며 Flexible segment의 두께가 얇은 경우와 두꺼운 경우를 각각 고려하였다. 시험 결과 Flexible segment의 지진시 터널 구조물에 발생하는 최대 가속도 저감 효과를 확인하였다. 그러나 Flexible segment가 얇은 경우 단주기파 적용시 최대가속도의 저감효과는 없었고, 두꺼운 경우 기반암 가속도가 클 경우 보다 효과적임을 확인하였다. 또한 동일 모델에 대하여 3차원 수치해석을 수행하여 지진시 거동을 파악한 결과, 시험 결과와 유사한 경향을 보임을 확인할 수 있었다.

키워드

원심모형시험

병렬터널

Flexible segment

수치해석

References

1.Baziar, M.H., Moghadam, M.R., Kim, D.S., Choo, Y.W. (2014), “Effect of underground tunnel on the ground surface acceleration”, Tunnelling and Underground Space Technology, Vol. 44, pp. 10-22.

2.Chen, Z.Y., Shen, H. (2014), “Dynamic centrifuge tests on isolation mechanism of tunnels subjected to seismic shaking”, Tunnelling and Underground Space Technology, Vol. 42, pp. 67-77.

3.Cilingir, U., Madabhushi, S.P.G. (2009), “A model study on the effects of input motion on the seismic behaviour of tunnels”, Soil Dynamics and Earthquake Engineering, Vol. 31, pp. 452-462.

4.Cilingir, U., Madabhushi, S.P.G. (2009), “Effect of depth on seismic response of circular tunnels”, Canadian Geotechnical Journal, Vol. 48, pp. 117- 127.

5.Lanzano, G. (2009), “Physical and analytical modeling of tunnels under dynamic loadings. Ph. D. Dissertation, University of Naples ‘FedericoII’ Naples.

6.Pitilakis, K., Tsinidis, G., Leanza, A., Maugeri, M. (2014), “Seismic behaviour of circular tunnels accounting for above ground structures interaction effects”, Soil Dynamics and Earthquake Engineering Vol. 67, pp. 1-15.

7.Yang, W., Hussein, M.F.M., Marshall, A.M. (2013), “Centrifuge and numerical modelling of ground-borne vibration from an underground tunnel”, Soil Dynamics and Earthquake Engineering Vol. 51, pp. 23-34.

Information

Publisher :Korean Tunneling and Underground Space Association
Publisher(Ko) :한국터널지하공간학회
Journal Title :Journal of Korean Tunnelling and Underground Space Association
Journal Title(Ko) :한국터널지하공간학회 논문집
Volume : 17
No :6
Pages :695-702
Received Date : 2015-11-16
Revised Date : 2015-11-23
Accepted Date : 2015-11-24
DOI :https://doi.org/10.9711/KTAJ.2015.17.6.695

Journal of Korean Tunnelling and Underground Space Association ISSN:2233-8292(Print) 2287-4747(Online) 한국터널지하공간학회 논문집

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