All Issue

2019 Vol.35, Issue 1
January 2019. pp. 5-15
Abstract

본 연구에서는 제주도 북동부 육・해상 및 북서부 육상에 위치한 현무암반에 대한 공내재하시험으로부터 계측된 변형계수와 RQD 및 RMR의 관계를 각각 살펴보았으며, 기존의 경험식들로부터 추정된 변형계수 값과 비교・분석하였다. 뿐만 아니라, 속도검층시험을 통하여 산정된 탄성파 속도비 및 동적 포아송 비와 변형계수의 관계에 대해서도 각각 살펴보았다. 그 결과, 다공성 구조 및 층상 구조가 특징인 제주도 현무암반의 경우, RQD 값만을 이용한 암반등급의 결정, 변형계수 계측방법의 선정 및 변형계수의 추정은 부적절하며, 최소한 RMR을 통하여 암반등급을 결정하고, 변형계수를 추정하는 것이 바람직하다는 것을 알 수 있었다. RMR을 이용한 기존의 변형계수 추정식은 제주도 현무암반의 변형계수에 비해 큰 값을 예측하는 경향을 보였으며, 탄성파 속도비 및 동적 포아송 비와 변형계수는 서로 정성적인 특성이 일치하는 관계에 있었다. 그리고, 적절한 제주도 현무암반의 변형계수를 추정하기 위한 RMR과 탄성파 속도비를 이용한 변형계수 추정식을 각각 제시하였다.

In this study, the in situ deformation moduli, which were measured by borehole loading tests at basaltic rock masses located in the northeastern onshore and offshore and the northwestern onshore of Jeju Island, were examined in relation to RQD and RMR. The measured deformation moduli were also compared with the estimated deformation moduli from conventional empirical formulas using RQD and RMR. In addition, the measured deformation moduli were analyzed with respect to both the velocity ratio (VP/VS) and dynamic Poisson’s ratio, which were obtained from the elastic wave velocities measured by velocity logging tests. As results, with only RQD, it was inappropriate to evaluate the quality of the Jeju island basaltic rock masses, which are characterized by vesicular structures, to select a measurement method of in situ deformation moduli, and to estimate the deformation moduli. On the other hand, it was desirable to evaluate the quality of the Jeju Island basaltic rock masses, and to estimate the deformation moduli by using RMR. The conventional empirical formulas using RMR overestimated the deformation moduli of the Jeju Island basaltic rock masses. There was qualitative consistency in the relation between velocity ratio and deformation moduli. To estimate appropriately the deformation moduli of the Jeju Island basaltic rock masses, empirical formulas were proposed as the function of RMR and velocity ratio, respectively.

References
1 

Ahn, T. (2011), "The Correlation Between RMR and Deformation Modulus by Rock Masses Using Pressuremeter", Journal of the Korean Geo-Environmental Society, Vol.12, No.1, pp.5-12 (in Korean).

2 

Aydan, Ő., Ulusay, R., and Kawamoto, T. (1997), "Assessment of Rock Mass Strength for Underground Excavations", International Journal of Rock Mechanics, Mining Science, Vol.34, No.3-4, pp.1-17.

10.1016/S1365-1609(97)00273-6
3 

Barton, N. (2007), Rock quality, seismic velocity, attenuation and anisotropy, Taylor & Francis, p.729.

4 

Bieniawski, Z.T. (1978), "Determining Rock Mass Deformability: Experience from Case Histories", International Jour. of Rock Mechanics, Mining Science and Geomechanics, Vol.15, pp.237-247.

10.1016/0148-9062(78)90956-7
5 

Bieniawski, Z.T. (1989), Engineering rock mass classifications, John Wiley & Sons, Inc. p.250.

6 

Cho, T.C., Lee, S.B., Hwang, T.J., and Won, K.S. (2009), "Variations of Mechanical Properties of Hallasan Trachyte with Respect to the Degree of Weathering", Tunnel and Underground Space, Vol.19, No.4, pp.287-303.

7 

Chun, B., Ryu, W., Sagong, M., and Do, J. (2009), "Indirect Estimation of the Rock Deformation Modulus based on Polynomial and Multiple Regression Analyses of the RMR System", International Journal of Rock Mechanics & Mining Sciences, Vol.46, pp.649-658.

10.1016/j.ijrmms.2008.10.001
8 

Deere, D.U., Hendron, A.J., Patton, F.D., and Cording, E.J. (1967), "Design of Surface and Near-surface Construction in Rock", Proceedings of the 8th U.S. Symposium on Rock Mechanics, pp.237-302.

9 

Eum, K.Y. (2002), Study on the Mechanical Properties of Volcanic Rocks in Chejudo, Master thesis, Yonsei University, p.63.

10 

Gokceoglu, C., Sonmex, H., and Kayabasi, A. (2003), "Predicting the Deformation Moduli of Rock Masses", International Journal of Rock Mechanics & Mining Sciences, Vol.40, pp.701-710.

10.1016/S1365-1609(03)00062-5
11 

Hoek, E. and Diederichs, M.S. (2006), "Empirical Estimation of Rock Mass Modulus", International Journal of Rock Mechanics & Mining Sciences, Vol.43, pp.203-215.

10.1016/j.ijrmms.2005.06.005
12 

Jo, C., Byun, J., and Hwang, S. (2006), "Considerations on the Difficulties in Velocity Logging in the Near Surface Environments", Geophysics and Geophysical Exploration, Vol.9, No.3, pp.185-192 (in Korean).

13 

Kim G.W. (1993), "Revaluation of 「Geomechanics Classifications of Rock Masses」", Proceedings of the Korean Geotechnical Society Conferences, pp.33-40 (in Korean).

14 

Kim, J.H. (2006), A Study on the Mechanical Characteristics and the Strength in Pyoseonri Basalt, Master thesis, Cheju National University, p.93 (in Korean).

15 

Kim, Y.K. and Choi, O.G. (1991), "Engineering Geological Characteristics of Volcanic Rocks of the Northwestern Cheju Island, Korea", The Journal of Engineering Geology, Vol.1, No.1, pp.19-37.

16 

Koo, H.B., Bae, G.J., Moon, H.D., and Hong, S.W. (1994), "An Evaluation of Rock Mass Rating System as Design Aids in Korea", Proceedings of the Korean Geotechnical Society Conferences, pp.209-216 (in Korean).

17 

Kwon, B.D. (2006), "On-Land Seismic Survey of Korea", Economic and Environmental Geology, Vol.39, No.4, pp.441-446 (in Korean).

18 

Leem, K.M., Park, J.O., Yu, Y.C., and Song, M.Y. (2009), "Geophysical Well-log Analysis of Andesite and Sedimentary Rocks in Myodo-dong, Yeosu, Southern Korea", Journal of Korean Earth Science Society, Vol.30, No.4, pp.401-408 (in Korean).

10.5467/JKESS.2009.30.4.401
19 

Moon, K., Park, S., Kim, Y., and Yang, S. (2014), "Mechanical Properties of basalt in Jeju Island with Respect to Porosity", Journal of the Korean Society of Civil Engineering, Vol.34, No.4, pp.1215-1225 (in Korean).

10.12652/Ksce.2014.34.4.1215
20 

Nam, J.M., Yun, J.M., Song, Y.S., and Kim, J.H. (2008a), "Analysis of Engineering Properties to Basalt in Cheju Island", Journal of Korean Geosynthetics Society, Vol.7, No.1, pp.12-21.

21 

Nam, J.M., Yun, J.M., Song, Y.S., and Kim, J.H. (2008b), "Analysis of Influence Factors to Compressive and Tensile Strength of Basalt in Cheju Island", The Journal of Engineering Geology, Vol.18, No.2, pp.215-225.

22 

Nam, J.M., Yun, J.M., and Song, Y.S. (2009), "Estimation to the Strength of Basalt in Jeju Island according to Rock Failure Criterions", The Journal of Engineering Geology, Vol.19, No.2, pp.153-163.

23 

Serafim, J.L. and Pereira, J. P. (1983), "Consideration of the Geomechanical Classification of Bieniawski", Proceedings of International Symposium on Engineering Geology in Underground Construction, Lisbon, Portugal, Vol.1, No.2, pp.33-44.

24 

Stewart, R.R., Huddleston, P.D., and Kan, T.K. (1984), "Seismic Versus Sonic Velocities: A Vertical Seismic Profiling Study", Geophysics, Vol.49, No.8, pp.1153-1168.

10.1190/1.1441745
25 

Sunwoo, C., Chung, S.K., Han, K.C., Hwang, S.H., and Lee, S.K. (2001), "Correlation Between the Rock Mass Classification Methods", Journal of the Korean Geotechnical Society, Vol.17, No.4, pp.127-134 (in Korean).

26 

Yang, S.B. (2014), "Comparative Study on Physical and Mechanical Characteristics of Volcanic Rocks in Jeju Island", Journal of the Korean Geotechnical Society, Vol.30, No.11, pp.39-49 (in Korean).

10.7843/kgs.2014.30.11.39
27 

Yang, S.B. (2015a), "Physical and Mechanical Characteristics of Basalts in Northwestern and Southeastern Jeju Island", Journal of the Korean Geotechnical Society, Vol.31, No.7, pp.41-52 (in Korean).

10.7843/kgs.2015.31.7.41
28 

Yang, S.B. (2015b), "Cohesion and Internal Friction Angle of Basalts in Jeju Island", Journal of the Korean Geotechnical Society, Vol.31, No.11, pp.33-40 (in Korean).

10.7843/kgs.2015.31.11.33
29 

Yang, S.B. (2016), "Strength Parameters of Basalts in Jeju Island according to Rock Failure Criterions", Journal of the Korean Geotechnical Society, Vol.32, No.3, pp.15-27 (in Korean).

10.7843/kgs.2016.32.3.15
30 

Yang, S. and Sassa, S. (2016), "Mechanical Characteristics and Design Strength Parameters due to Vesicular Property of Basalts", Journal of Japan Society Civil Engineers, Ser. B3, Vol.72, No.2, pp.437-442 (in Japanese).

31 

Yang, S. and Sassa, S. (2017), "Effects of Porosity on Mechanical Characteristics of Vesicular Basalts", Proceedings of the 27th International Ocean and Polar Engineering Conference, pp.705-711.

32 

Yoon, S.H. and Ko, K.W. (2011), Topography, Geology and Underground Water in Jeju Island, Nae Ha Publishing Company, pp.5-57 (in Korean).

Information
  • Publisher :The Korean Geotechnical Society
  • Publisher(Ko) :한국지반공학회
  • Journal Title :Journal of the Korean Geotechnical Society
  • Journal Title(Ko) :한국지반공학회 논문집
  • Volume : 35
  • No :1
  • Pages :5-15
  • Received Date :2018. 10. 01
  • Accepted Date : 2019. 01. 11