Tunnel and Underground Space (터널과지하공간)

Korean Society for Rock Mechanics and Rock Engineering (한국암반공학회)
권호 표지

Classification of Rock Mass on Cutting Slopes in Muakjae, Seoul

서울 무악재 절취사면에서의 암판정 연구

  • Published : 1999.06.01
Download PDF
⟨ Previous Next ⟩

Abstract

There are substantial difficulties in assessing the volume of soill/rock to be excavated and the cost thereof, which is attributable to the subjective and qualitative methods of rock mass classification prevailing at the moment. This paper intends to introduce more objective and quantitative rock mass classification method easily applicable to the excavation of granites in Muakjae, Seoul. As a result of such study it is proven that Schmidt hammer and point load strength tests are fairly reliable and easily applicable to estimate and quantify uniaxial compressive strength of granitic material in Seoul. In an efforts to confirm the granitic rock mass conditions in 12 meters underground, seismic refraction surveys were made on the top of vertical exposures from where underlying rock mass conditions could be directly inspected. Rock mass boundaries determined by seismic refraction methods were found to agree within a 1m variance with visible differences in rock mass conditions in the vertical exposure beneath the test site. Thus it can be concluded that detailed geotechnical mapping on cutting slopes is a most efficient, dependable and cost-effective technique in assessing likely excavation conditions of shallow granitic mass in Seoul.

주관적이고 정성적인 암판정 방법들 때문에 굴착될 토충과암석의 물량과 이에 따른 굴착비용 산정시에 일반적으로 어려움이 많다. 그러므로 본 논문은 굴착 목적에서 서울 화강암에 대하여 객관적이고 정량적이고 쉽게 적용될 수 있는 암반판정 방법들을 제시한다. 슈미트해머와 점하중강도 시험들은 서울 화강암의 암석에 대한 일축압축강도를 정량적으로 추정하기 위한 신뢰도가 높고 손쉽게 수행할 수 있는 방법들로서 입중되었다. 또한 지표면에서 약 12m 깊이인 천부지역의 화강암 암반상태를 확인하기 위하여, 지반조건을 직접 관찰할 수 있는 수직 절취사면의 최상부에서 현장 탄성파탐사 방법이 사용되었다. 이로서 현장 탄성파탐사로서 암반 상태 및 깊이를 판단하는 신뢰성을 확인할 수 있었는데 매우 정확한 1 m의 오차만 있었다. 그러므로 비교적 천부인 서을 화강암 암반의 굴착난이도 상태를 판단하기 위하여 현장에서 절취사면에 대한 정밀 지반조사방법은 매우 유용하고 경제적인 방법으로서 고려될 수 있다.

Keywords

References

  1. 대한토목학회 1992년도 학술발표회 개요집(Ⅰ) 암판정에 관한 고찰 이수곤
  2. 대한토목학회 1994년도 학술발표회 논문집(Ⅰ) 절취공사시의 암판정 방법 연구 이수곤;이송
  3. Weathering(2nd ed.) Ollier, C.
  4. 서울의 지질도(1:50,000) 홍승호(외)
  5. 토목시공 고등기술강좌(Series Ⅲ) 암석과 불연속면의 분류 및 공학적 특성 이수곤
  6. Transactions of the Institution of Mining and Metallury;Section A-Mining Industry v.80 Logging the mechanical character of rock Franklin, J.A.;Brock, E.;Walton, G.
  7. Air Force Weapons Laboratory Technical Report, AFWL-TR-65-116 Engineering Classification and Index Properties for Intact Rock Deere, D.U.;Miller, R.P.
  8. Geotechnical Manual for Slopes(2nd ed.) GCO(Geotechnical Control Office)
  9. Engineering Geology for Civil Engineering Construction Goodman, R.E.
  10. 건설표준품셈 대한건설협회
  11. Trans. Inst. Min. Metall.;Section A-Mining Industry v.80 Selection of open pit excavation and loading equipment Atkinson, T.
  12. Proceedings of the Engineering Group of the Geological Society 20th Regional Meeting on Site Investigation Practice: Assessing BS 5930 v.2 Discussion on rock descriptions Hencher, S.
  13. Proceedings of the 7th Southeast Asian Geotechnical Conference v.1 The description and classification of weathered rocks in Hong Kong for engineering purposes Hencher, S.R.;Martin, R.P.
  14. Bulletin of the International Association of Engineering Geology no.24 Rock and soil description and classification for engineering geological mapping IAEG(International Association of Engineering Geology)
  15. Bulletin of the International Association of Engineering Geology no.17 Engineering classification and index properties of a weathered granite Irfan, T.Y;Dearman, W.R.
  16. Int. J. of Rock Mech. and Min. Sci. & Geomech. Abstr. v.18 Basic geotechnical description of rock masses ISRM(International Society for Rock Mechanics)
  17. Quarterly Journal of Engineering Geology v.22 no.1 A revision of the description and classification of weathered granite and its application to granites on Korea Lee, S.G.;De Freitas, M.H.
  18. Geophysical Exploration Heiland, C.A.
  19. Int. J. of Rock Mech. and Min. Sci. & Geomech. Abstr. v.16 no.2 Suggested methods for determining the uniaxial compressive strength and deformability of rock materials ISRM(International Society for Rock Mechanics)
  20. Int. J. of Rock Mech. and Min. Sci. & Geomech. Abstr. v.16 no.2 Suggested methods for determining water content, porosity, density, absorption and related properties and swelling and slake-durability index properties ISRM(International Society for Rock Mechanics)
  21. Ph.D thesis, Imperial College, University of London Point Load Testing of Rocks Broch, E.
  22. Int. J. of Rock Mech. and Min. Sci. & Geomech. Abstr. v.9 The point-load strength test Broch, E.;Franklin, J.A.
  23. Int. J. of Rock Mech. and Min. Sci. & Geomech. Abstr. v.22 Suggested methods for determining point load strength: Revised version ISRM(International Society for Rock Mechanics)
  24. Bulletin of the International Association of Engineering Geology no.47 Weathering of the Massiacgneiss Dobereiner, L.(et al.)
  25. Int. J. of Rock Mech. and Min. Sci. & Geomech. Abstr. v.19 Experimental studies of the influence of rock anisotropy on size and shape effects in point load trength testing Greminger, M.
  26. Proceedings of the Conference on Rock Engineering Comparison of Schmidt hammer, point load and unconfined compression tests in Carboniferous strata Carter, P.G.;Sneddon, M.
  27. 대한토목학회논문집 v.15 no.4 점하중 강도를 이용한 한국화강암의 일축 압축강도 추정방법 이수곤;이송
  28. British Geomorphological Research Group Technical Bulletin v.18 Field assessment of rock hardness using the Schmidt test hammer Day, M.J.;Goudie, A.S.
  29. Int. J. of Rock Mech. and Min. Sci. & Geomech. Abstr. v.15 Suggested methods for determining hardness and abrasiveness of rocks ISRM(International Society for Rock Mechanics)
  30. Operating Instructions for the L-type Schmidt Jammer Schmidt, E.
  31. 대한토목학회논문집 v.14 no.1 슈미트해머 수치를 이용한 한국 화강암의 일축 압축강도 추정방법 이수곤;이송
  32. Int. J. of Rock Mech. and Min. Sci. & Geomech. Abstr. v.15 no.6 Suggested methods for the quantitative description of discontinuities in rock masses ISRM(International Society for Rock Mechanics)