Estimation of elastic and plastic zones near a tunnel considering in situ rock mass conditions and the damage induced by excavation

Myung* Sagong; Kyuho Paik

doi:None

All Issue

2004 Vol.6, Issue 3 Preview Page Next Page

Estimation of elastic and plastic zones near a tunnel considering in situ rock mass conditions and the damage induced by excavation 원지반의 암반조건과 시공으로 인한 손상을 고려한 터널주변 탄․소성영역의 산정

30 September 2004. pp. 227-235

PDF XML

Abstract

Tunneling in rock mass produces two types of damages in the vicinity of a tunnel: structural and constructional damages. Structural damage represents the damage induced by the unbalance of geostatic stress caused by the tunneling, and constructional damage is the damage produced during the construction. In this study, formulations of tangential and radial stresses in the elastic and plastic zones near a tunnel, and the calculation of radius of plastic zone surrounding a tunnel are introduced by modifying the Hoek-Brown criterion of 2002 edition, which has capability of considering in situ rock mass characteristics and construction damage. From the parametric study, influences of rock mass quality, uniaxial compressive strength of intact rock, and the dimension of the tunnel on the plastic zone are investigated. The accuracy of the proposed approach is evaluated by comparing with results from the previous study.

Keywords

Elastic zone

plastic zone

damage zone

tangential stress

radial stress

터널의 시공은 터널주변 지반에 구조적인 손상과 시공상의 손상을 불러일으킨다. 여기서의 구조적인 손상이란 터널굴착으로 인한 원지반응력의 교란으로 인하여 발생하는 것을 의미하며, 시공상의 손상이란 시공방법에 따른 주변지반의 손상을 의미한다. 본 논문에서는 원지반의 특성과 시공 중 손상을 고려할 수 있는 Hoek과 Brown 2002년도 공식을 이용하여 터널주변 탄․소성 영역에 작용하는 접선 및 반경방향의 응력 산정을 위한 식과 터널주변 소성영역의 산정방법이 제시되었다. 또한, 매개변수분석을 통하여 암반의 등급, 무결암의 일축압축강도, 그리고 터널의 크기와 소성영역간의 상관관계를 조사하였으며, 기존의 연구에서 제안된 방법과의 비교를 통하여 본 연구에서 제안된 방법의 정확도를 검증하였다.

키워드

탄성영역

소성영역

손상영역

접선응력

반경응력

References

1. Brown, E. T., Bray, J. W., and Landanyi, B. (1983), “Ground Response Curves for Rock Tunnels”, Journal of Geotechnical Engineering, Vol. 109(1), pp. 15-39.

2. Cai, M., Kaiser, P. K., and Martin, C. D. (2001), “Quantification of rock mass damage in under- ground excavations from microseismic event monitoring”, International Journal of Rock Mecha- nics and Mining Science, Vol. 38, pp. 1135-1145.

3. Carranza-Torres, C., and Fairhurst, C. (1999), “The elasto-plastic response of underground excavations in rock masses that satisfy the Hoek-Brown failure criterion”, International Journal of Rock Mechanics and Mining Sciences, Vol. 36, pp. 777-809.

4. Hoek, E. (1998), Rock Engineering course note by Evert Hoek, http://www.rocscience.com/hoek/ PracticalRockEngineering.asp, retrieved on Jun 5, 2004.

5. Hoek E. and Brown E. T. (1980a), “Empirical strength criterion for rock masses”, Journal of Geotechnical Engineering Division, Vol 106, No. GT9, pp. 1013-1035.

6. Hoek E. and Brown E. T. (1980b), “Underground excavation in rock”, The institute of mining and metallurgy, London. pp. 107.

7. Hoek E. and Brown E. T. (1997), “Practical estima- tion of rock mass strength”, International Journal of Rock Mechanics & Mining Sciences, Vol 34(8), pp. 1165-1186.

8. Hoek E., Carranza-Torres C., and Corkum B. (2002), “Hoek-Brown failure criterion-2002 edition”, 5th North American Rock Mechanics Symposium and 17th Tunneling Association of Canada Confe- rence: NARMS-TAC, pp. 267-271.

9. Londe, P. (1988), “Discussion on the Determi- nation of the Shear Stress Failure in Rock Masses”, Journal of Geotechnical Engineering, Vol. 114(3), pp. 374-376.

10. Pan, X. D. and Brown, E. T. (1996), “Influence of Axial Stress and Dilatancy on Rock Tunnel Stability”, Journal Geotechnical Engineering, Vol. 122(2), pp. 139-148.

11. Pusch, R. and Stanfors, R. (1992), “The zone of disturbed around blasted tunnels at depth”, International Journal of Rock Mechanics and Mining Science & Geomechanics Abstract, Vol. 29, No. 5, pp. 447-456.

12. Timoshenko, S. P., and Goodier, J. N. (1970), Theory of Elasticity International Third Edition, McGraw-Hill, Singapore, pp. 69.

13. Wang, Y. (1996), “Ground Response of Circular Tunnel in Poorly Consolidated Rock”, Journal of Geotechnical Engineering, Vol. 122(9), pp. 703- 708.

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 : 6
No :3
Pages :227-235

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

All Issue