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Effect of Joint Cohesive Strength on the Earth Pressure against the Support System in a Jointed Rock Mass

절리형성 암반지층 굴착벽체 작용토압에 대한 절리 점착강도의 영향

Moorak Son*
,
Solomon Adedokun
손 무락*
,
아데도쿤 솔로몬
Prof., Department of Civil Engrg., Daegu Univ
Graduate Student, Department of Civil Engrg., Daegu Univ.
*교신저자. *Corresponding Author. 
31 July 2014. pp. 41-53
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Abstract

This study examined the magnitude and distribution of the earth pressure on the support system in a jointed rock mass by considering different joint shear strength, rock type, and joint inclination angle. The study particularly focused on the effect of joint cohesive strength for a certain condition. Based on a physical model test (Son and Park, 2014), extended parametric studies were conducted considering rock-structure interactions based on the discrete element method, which can consider the rock and joint characteristics of rock mass. The results showed the earth pressure was strongly affected by the joint cohesive strength as well as the rock type and joint inclination angle. The study indicated that the effect of joint cohesive strength was particularly significant when a rock mass was under the condition of joint sliding. This paper investigates the magnitude of joint cohesive strength to prevent a joint sliding for each different condition. The test results were also compared with Peck’s earth pressure, which has been frequently used for soil ground. The comparison indicated that the earth pressure in a jointed rock mass can be significantly different from that in soil ground. This study is expected to provide a better understanding of the earth pressure on the support system in a jointed rock mass.

Keywords
Rock excavation
Support system
Earth pressure
Joint cohesive strength
Rock type
Joint inclination angle
Rock-structure interaction

본 연구는 절리형성 암반지층 굴착벽체 작용토압의 크기 및 분포에 대해서 절리의 점착강도, 암석종류 및 절리경사각을 달리하여 조사하였다. 본 연구는 특히 절리 점착강도의 영향에 대해 초점을 두었다. 실내모형실험(Son and Park, 2014)에 근거하여 암석과 구조물의 상호작용을 고려하면서 확장된 매개변수 연구를 수행하였다. 이 때 매개변수 연구는 암석과 절리의 거동특성을 고려할 수 있도록 개별요소법에 근거하여 수행하였다. 연구결과 굴착벽체에 작용하는 토압은 암석 및 절리경사각 뿐만아니라 절리 점착강도에 의해서 크게 영향을 받는 것으로 나타났다. 절리 점착강도의 영향은 특히 절리가 활동될 수 있는 조건에서 크게 나타났다. 본 연구에서는 서로 다른 조건에서 절리의 활동을 방지하기 위한 절리 점착강도의 크기를 조사하였다. 연구결과는 또한 토사지반에서의 토압산정을 위해 자주 이용되는 Peck의 경험토압과도 비교되었다. 비교결과 절리형성 암반지층에서 발생하는 토압은 토사지반에서의 토압과는 크게 다를 수 있다는 것을 나타냈다. 본 연구결과는 향후 절리형성 암반지층 굴착벽체 작용토압에 대해 보다 나은 이해를 제공할 수 있을 것으로 기대된다.

References
1
1.Bjerrum, L., Frimann Clausen, C. J., and Duncan, j. M. (1972), Earth pressure on flexible structures: a state-of-the-art-report. Proc. 5th European Conf. Soil Mech., Madrid, 2, pp.169-196.
2
2.Chae, Y. S. and Moon, I. (1997), Earth pressure on retaining wall by considering local soil condition. Korean Geotechnical Society ’94 fall conference paper, pp.129-138.
3
3.Haahash, Y. M. A. and Whittle, A. J. (2002), Mechanism of load transfer and arching for braced excavations in clay. Journal of Geoteh. and Geoenviron. Eng., Vol.128, No.3, pp.187-197.
4
4.Itasca Consulting Group, Inc. (2004), Universal Distinct Element Code, User's Manual, Minneapolis, Minnesota, U.S.A
5
5.Jeong, E. T. and Kim, S. G. (1997), Case study of earth pressure distribution on excavation wall of multi-layered soil. Korean Geotechnical Society ’97 spring conference paper, pp.78-80.
6
6.Lambe, T. W. and Whitman, R. V. (1978), Soil mechanics, SI version, John Wiley & Sons Inc., New York.
7
7.Laio, S. S. C. and Neff, T. L. (1990), Estimating lateral earth pressure for design of excavation support, Proceedings, Design and Performance of earth retaining structures, ASCE special conference, Ithaca, New York, pp.489-509.
8
8.Peck, R.B. (1969), “Deep Excavations and Tunneling in Soft Ground. State-of-the-Art report”, Proceedings of the 7th International Conference on Soil Mechanics and Foundation Engineering, Mexico City, State-of-the Art Volume, pp.225-290.
9
9.Potts, D. M. and Fourie, A. B. (1986), A numerical study of the effect of wall deformation on earth pressures. Intern. Journal of Numerical Ana. Methods in Geomech. Vol.10, No.4, pp.383-405.
10
10.Son, M. (2013), Earth pressure on the support system in jointed rock mass, Canadian Geotech. Journal, Vol.50, No.5, pp.493-502.
11
11.Son, M. and Park, J. (2014), Physical model test and numerical simulation of excavation walls in jointed rock masses, Canadian Geotech. Journal, 10.1139/cgj-2013-0081
12
12.Tschebotarioff, G. P. (1973), Foundations, Retaining and Earth Structures. 2nd Ed., MGH.
13
13.Wong, I. H., Poh, T. Y., and Chuah, H. L. (1997), Performance of excavations for depressed expressway in Singapore, Journal of Geoteh. and Geoenviron. Eng., Vol.123, No.7, pp.617-625.
14
14.Worden, F. T. and Achmus, M. (2013), Numerical modeling of three-dimensional active earth pressure acting on rigid walls, Computer and Geotechnics, Vol.51, pp.83-90.
15
15.Yoo, C. S. and Kim, Y. J. (2000), “Deep excavation in soil, including rock with layers on retaining wall and apparent horizontal displacement of earth pressure”, Journal of Korean Geotechnical Society, Vol. 16, No. 4, pp. 43-50.
Information
  • Publisher :The Korean Geotechnical Society
  • Publisher(Ko) :한국지반공학회
  • Journal Title :Journal of the Korean Geotechnical Society
  • Journal Title(Ko) :한국지반공학회 논문집
  • Volume : 30
  • No :7
  • Pages :41-53
  • Received Date : 2014-04-23
  • Revised Date : 2014-07-01
  • Accepted Date : 2014-07-16
  • DOI :https://doi.org/10.7843/kgs.2014.30.7.41
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