Study on flexible segment efficiency for seismic performance improvement of subsea tunnel

Dong-In  Jang; Jong-Ill  Kim; Chang-Won  Kwak; Inn-Joon  Park

doi:10.9711/KTAJ.2017.19.3.503

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2017 Vol.19, Issue 3 Preview Page Next Page

Study on flexible segment efficiency for seismic performance improvement of subsea tunnel 해저터널 내진성능 향상을 위한 Flexible segment 효용성 연구

31 May 2017. pp. 503-515

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Abstract

Underground structures that have recently become larger are required to be stable not only during normal times but also during earthquakes. Especially, it is very important to maintain the stability of the subsea tunnels during the earthquake. The objective of this paper is to verify the effectiveness of the flexible segment, which is one of the breakthrough facilities to maintain the stability of the subsea tunnel during the earthquake using the shaking table test. Another goal of this paper is to propose the optimum position of the flexible segment through 3D dynamic numerical analysis based on the verified results from shaking table tests. The 1g shaking table test considering the similarity ratio (1:100) to the cross section of the selected artificial subsea tunnel was carried out considering the Geongju and Artificial seismic waves, longitudinal and lateral wave, and with/without flexible segments eight times or more. As a result of the shaking table test, it was confirmed that the flexible segment is effective in improving the seismic performance of the undersea tunnel in all the experimental results. In addition, 3D dynamic numerical analysis was performed to select the optimum position of the flexible segment which is effective for improving seismic performance. As a result, it was confirmed that the seismic acceleration is attenuated when the flexible segment is installed adjacent to the branch section in subsea tunnel.

Keywords

Flexible segment

Subsea tunnel

Shaking table test

Geongju seismic wave

Artificial seismic waves

최근 대형화되고 있는 지하구조물은 평상시는 물론 지진시에도 안정성을 확보하여야 한다. 특히 지하구조물 중에서도 해저터널은 지진시 안정성 유지가 매우 중요하다고 할 수 있다. 본 논문의 목표는 해저터널의 지진시 안정성 유지에 획기 적인 시설물 중의 하나인 Flexible segment에 대해서 진동대 시험을 이용한 효용성 검증이다. 검증된 결과를 토대로 3차 원 동해석을 통해 Flexible segment의 최적위치를 제안하는 것이 또 다른 하나의 논문 목표이다. 본 연구 수행을 위해 선 정한 가상해저터널 단면에 상사율(1:100)을 고려한 1g 진동대 시험(1g Shaking Table Test)을 경주지진파, 인공지진파, 종방향, 횡방향, Flexible segment유무 등을 고려해서 모두 8회 이상 수행하였다. 진동대 시험 수행결과 전 시험 모두에 서 Flexible Segment가 해저터널 내진성능향상에 효과가 있음을 확인하였다. 또한 시험적으로 내진성능 향상에 효과가 검증된 Flexible segment의 최적 위치를 선정하기 위하여, 3차원 동적 수치해석을 수행하였다. 그 결과 분기구간에서 Flexible segment를 인접해 설치할 경우 지진가속도가 감쇠하는 것을 확인할 수 있었다

키워드

Flexible segment

해저터널

진동대 시험

경주지진파

인공지진파

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. (2011a), “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. (2011b), “Effect of depth on seismic response of circular tunnels”, Canadian Geotechnical Journal, Vol. 48, pp. 117-127.

5.Iai, S. (1989), “Similitude for shaking-table tests on soil-structure-fluid model in 1g gravitational field”, Soils Found. Vol. 29, No.1, pp. 105-118.

6.Kim, H., Kang S.O., Yoo, K.S., Kim, S.H. (2017), “Design considerations and field applications on inflatable structure system to protect rapidly flooding damages in tunnel”, Journal of Korean Tunnelling and Underground Space Association, Vol. 19, No. 2, pp. 161-177.

7.Kwak, C.W., Park, I.J. (2015), “Seismic behaviors of twin tunnel with flexible segment”, Journal of Korean Tunnelling and Underground Space Association, Vol. 17, No. 6, pp. 695-702.

8.Kwak, C.W., Jang, D.I., Park I.J., Park, S.Y. (2016), “Seismic response analysis of virtual honam-jeju subsea tunnel”, Journal of Korean Tunnelling and Underground Space Association, Vol. 18, No. 3, pp. 319-329.

9.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 : 19
No :3
Pages :503-515
Received Date : 2017-04-13
Revised Date : 2017-04-24
Accepted Date : 2017-05-17
DOI :https://doi.org/10.9711/KTAJ.2017.19.3.503

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

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