KSCE Journal of Civil and Environmental Engineering Research (대한토목학회논문집)

Korean Society of Civil Engeneers (대한토목학회)
권호 표지
DOI QR코드

DOI QR Code

Estimation of Elastic Modulus in Rock Mass for Assessing Displacment in Rock Tunnel

암반터널에서의 변위파악을 위한 암반 탄성계수 추정

  • 손무락 (대구대학교 토목공학과) ;
  • 이소단 (중국 강소성 만성직단) ;
  • 이원기 (대구대학교 토목공학과)
  • Received : 2010.09.16
  • Accepted : 2010.11.16
  • Published : 2011.04.30
Download PDF
⟨ Previous Next ⟩

Abstract

Elastic modulus in rockmass is an important factor to represent the characteristic of rock deformation and is used to estimate the displacement due to tunnel excavation. Nevertheless, the study to estimate the elastic modulus, which condisiders the rock type and joint characteristics (joint shear strength and joint inclination angle), has been done in less frequency. Accordingly, this study is aimed at providing the method to estimate the elastic modulus of rockmass in the various rock and joint conditons and the results grasped from the study. For this purpose, the 2D discrete numerical analysis will be carried out and the displacements due to tunnel excavation will be investigated with the consideration of rock and joint conditions. Then the displacement results will be used to estimate the elastic modulus of rockmass in which rock and joint conditions are considered with the utilization of the elastic theory of circular tunnel. The results of elastic modulus, which considers the conditions of various rock and joint, would be expected to have a great practical use in field.

암반에서의 탄성계수는 암반의 변형특성을 나타내는 매우 중요한 인자로서 암반에서의 터널굴착으로 인한 내공변위를 파악하는데 이용된다. 그럼에도 불구하고 현재까지는 암석종류 및 절리특성을 반영하여 탄성계수를 산정하는 연구는 미흡한 것으로 판단된다. 따라서, 본 연구는 다양한 암석 및 절리상태에서 암반의 탄성계수를 추정하는 방법과 그 결과를 제시하고자 한다. 이를 위해서 2차원 개별요소법에 근거한 수치해석이 수행될 것이며 이를 통해 암석과 절리상태가 고려된 터널굴착 유발 내공변위가 조사될 것이다. 조사된 변위결과는 암반에서의 원형터널에 대한 탄성이론을 역이용하여 암석종류 및 절리특성이 반영된 탄성계수를 추정하는데 사용될 것이다. 본 연구를 통해 암석종류 및 절리특성을 고려하여 추정된 탄성계수는 향후 실무에서 절리가 형성된 암반터널에서의 발생변위를 파악함에 있어서 그 활용도가 매우 클 것으로 기대된다.

Keywords

References

  1. Barton, N. R. (1976) The shear strength of rock and rock joints, Int. J. Mech. Min. Sci. & Geomech. Abstr. Vol. 13, No. 10, pp. 1-24. https://doi.org/10.1016/0148-9062(76)90221-7
  2. Bieniawski, Z. T. (1976) Rock mass classification in rock engineering, John Wiley& Sons, NY.
  3. Bieniawski, Z. T. (1978) Determining rock mass deformability: Experience from case histories. Int. J. Rock Mechanics Miner. Sci. and Geomechanics Abstr., Vol. 15, No. 5, pp. 237-247. https://doi.org/10.1016/0148-9062(78)90956-7
  4. Bienniawski, Z. T. (1989) Engineering Rock Mass Classification, John Wiley & Sons, NY.
  5. Clerici, A. (1993) Indirect determination of the modulus of deformation of rock masses-case histories. Proc. Symp. EUROCK, Rotterdam, A. A. Balkema, Eds. L. M. Riberio e Sousa, and N. F. Grossman, pp. 509-517.
  6. Coulson, J. H. (1970) The Effects of Surface Roughness on the Shear Strength of Joints in Rock, Ph.D Dissertation, Univ. of Illinois at Urbana-Champaign.
  7. Goodman, R. E. (1989) Introduction to rock mechanics. John Wiley & Sons, New York.
  8. Grimstad, E. and Barton, N. (1993) Updating the Q-system for NMT. Proc. Int. Symp. on Sprayed Concrete, Fagernes, Norwegian Concrete Association, Norway, pp. 44-66.
  9. Hoek, E. and Brown, E. T. (1980) Underground Excavations in Rock, Institution of Mining and Metallurgy, London.
  10. Hoek, E. and Brown, E. T. (1998), Practical estimates of rock mass strength. Int. J. Rock Mech. Min. Sci. Vol. 34, No. 8, pp. 1165-1186.
  11. Kirsch, G. (1898) Die theorie der elastizitat und die bedurfnisse der festigkeitslehre, Veit. Ver. Deut. Ing., Vol. 42, No. 28, pp 797-807.
  12. Palmstrom, A. (1996) Characterizing rock masses by the RMi for use in practical rock engineering, Part 1: the development of the rock mass index (RMi), Tunneling and Underground Space Technology, Vol. 11, No. 2, pp. 175-186. https://doi.org/10.1016/0886-7798(96)00015-6
  13. Palmstrom, A. and Singh, R. (2001) The deformation modulus of rock masses-comparisons between in situ tests and indirect estimates, Tunnelling and Underground Space Technology, Vol. 16, pp. 115-131. https://doi.org/10.1016/S0886-7798(01)00038-4
  14. Serafim, J. L. and Pereira, J. P. (1983) Considerations on the Geomechanical Classification of Bieniawski, Proc. Symp. on Engineering Geology and Underground Openings, Lisboa, pp. 1133-1144.
  15. UDEC User's Manual. (2004) ITASCA Consulting Group, Minnesota, U.S.A 2004.