• Title/Summary/Keyword: 수정된 RMR

Search Result 26, Processing Time 0.031 seconds

A Study on Rock Mass Rating system(RMR) and Modified Method (RMR 분류방법 및 수정 방법의 고찰)

  • 허종석
    • Proceedings of the Korean Geotechical Society Conference
    • /
    • 2003.06b
    • /
    • pp.51-64
    • /
    • 2003
  • Bieniawski에 의해 개발된 RMR은 암석강도 및 불연속면, 지하수 등의 6개 인자에 따라 분류되어, 이들을 합산하여 결정된다. RMR 분류법은 각 요소들에 대한 평가가 비교적 쉽고, 다양한 응용을 거쳐 여러 분야에 적용되어 국내에서도 가장 널리 사용하고 있는 암반분류 방법 중의 하나이다. RMR 분류결과는 터널의 유지시간, 최대 무지보폭의 예측, 지보량 산정, 암반의 물리적 특성값 예측 등에 적용될 수 있다. 또한 RMR 분류법을 사면안정, 댐 기초, 심부 광산 등에 적용하거나, RMR 분류법의 미비한 부분을 보완하기 위한 여러 가지 수정방법이 제시되었다.

  • PDF

A Suggestion of the Modified Weighting Values of the RMR Parameters Using a Multiple Regression Analysis on Rock Slopes (암반사면을 대상으로 다변량 수량화 기법을 응용한 RMR 인자의 수정 가중치 제안)

  • Chae Byung-Gon;Kim Kwang-Sik;Cho Yong-Chan;Seo Yong-Seok
    • The Journal of Engineering Geology
    • /
    • v.16 no.1 s.47
    • /
    • pp.85-96
    • /
    • 2006
  • This study was conducted to suggest a method to determine weighting values of each parameter of the RMR system considered with geologic characteristics of a study area. This study reviewed the weighting values of the RMR system for the Cretaceous sedimentary rocks distributed in Ulsan area. Based on the data of field survey at the study area, a multiple regression analysis was used to set up an optimal weighting values of the RMR parameters. For the multiple regression analysis, each parameter of the RMR and the slope gradient were regarded as the independent variable and the dependent variable, respectively. The analysis result suggested a modified weighting values of the RMR parameters as follows; 30 for the intact strength of rock; 18 for RQD; 8 for spacing of discontinuities; 32 for the condition of discontinuities; and 12 for ground water.

A Study of the Relationships among RMR, Q-system and GSI Applied to Classify Rock Mass of Limestone Mine (석회석 광산의 암반 분류에 적용된 RMR, Q-system, GSI 간의 상관성 연구)

  • Yoon, Yong-Kyun;Lee, Hong-Woo
    • Explosives and Blasting
    • /
    • v.35 no.4
    • /
    • pp.27-35
    • /
    • 2017
  • A total of 22 sites around openings of limestone mine are chosen to assess rock mass classification schemes such as RMR, Q-system, and GSI. RMR and Q are modified to estimate the relationship with GSI. Q' is the modified Q with SRF=1.0 and $J_w=1.0$. Rock mass is assumed to be completely dry and very favorable discontinuity orientations are assumed to estimate ${RMR_{89}}^{\prime}$. Relationships of Q-Basic RMR, Q-Total RMR, ${GSI-RMR_{89}}^{\prime}$, and GSI-Q' are analyzed, in which a correlation of ${GSI-RMR_{89}}^{\prime}$ is found to be the highest. Failure strains are calculated using the modulus ratios and most measuring sites appear to be stable with low failure strain class.

Consideration for evaluation patterns of normalized RMR parameters (정규화한 RMR 변수들의 평가 경향에 대한 고찰)

  • Lee, Seong-Min;Lee, Yeon-Hee;Kim, Sun-Myung
    • Journal of Korean Tunnelling and Underground Space Association
    • /
    • v.14 no.1
    • /
    • pp.23-35
    • /
    • 2012
  • Due to the convenience, RMR has been widely applied in civil engineering works such as tunnel, slope, and so on. Many researchers have studied to suggest more simple and trustable RMR by modifying its parameters. However, those researches have just focused on looking for easy modified-RMRs by reducing number of parameters using various statistical analyses. Therefore, this research studied questions of modified-RMRs and gaps between RMR and its parameters. Approximately 2,000 parameters of 400 RMRs from various tunnel sites were normalized respectively and compared with one another to study their relations and divergences. The comparison results showed that there were common patterns among RMR and parameters. Data of uniaxial compressive strength and RQD, qualitative parameters, were located in upper side of RMR line. Discontinuity condition and ground water, quantitative oriented parameters, were opposite to them. It means if both qualitative and quantitative parameters can be properly combined then it can be easy to make simple and easy modified-RMRs without using difficult statistics. This results also show that the majority of field engineers used to estimate RMR conservatively when they did quantitative oriented parameters.

Suggestion of a Modified RMR based on Effect of RMR Parameters on Tunnel Displacement in Sedimentary Rocks (퇴적암 기반 터널에서의 지질인자별 변위 영향도를 고려한 RMR 수정 제안)

  • Seo, Yong-Seok;Yim, Sung-Bin;Na, Jong-Hwa;Park, Si-Hyun
    • The Journal of Engineering Geology
    • /
    • v.18 no.2
    • /
    • pp.197-205
    • /
    • 2008
  • Total displacement under non-reinforcement is a quantitative index of rock mass behavior during tunnel excavation and depends widely upon geological characteristics. The primary purpose of this study is to suggest a rock mass evaluation method, well representing tunnel behavior during excavation, according to rock type. A 3-D numerical analysis was carried out, with consideration of the shape of tunnel section, excavation condition and so forth, in a sedimentary rock-based tunnel, and total displacements under non-reinforcement according to rock mass class were calculated. Finally, quantification analysis was carried out to assess correlation of the total displacement with RMR parameters. As the result, a modified RMR system fer quantification of rock mass behavior during tunnel excavation is suggested.

Geometric Analysis of Fracture System and Suggestion of a Modified RMR on Volcanic Rocks in the Vicinity of Ilgwang Fault (일광단층 인근 화산암 암반사면의 단열계 기하 분석 및 암반 분류 수정안 제시)

  • Chang, Tae-Woo;Lee, Hyeon-Woo;Chae, Byung-Gon;Seo, Yong-Seok;Cho, Yong-Chan
    • The Journal of Engineering Geology
    • /
    • v.17 no.3
    • /
    • pp.483-494
    • /
    • 2007
  • The properties of fracture system on road-cut slopes along the Busan-Ulsan express way under construction are investigated and analyzed. Fracture spacing distributions show log-normal form with extension fractures and negative exponential form with shear fractures. Straight line segments in log-log plots of cumulative fracture length indicate a power-law scaling with exponents of -1.13 in site 1, -1.01 in site 2 and -1.52 in site 3. It is likely that the stability and strength of rock mass are the lowest in site 1 as judged from the analyses of spacing, density and inter-section of fractures in three sites. In contrast, the highest efficiency of the fracture network for conducting fluid flow is seen in site 3 where the largest cluster occupies 73% through the window map. Based on the field survey data, this study modified weighting values of the RMR system using a multiple regression analysis method. The analysis result suggests a modified weighting values of the RMR parameters as follows; 18 for the intact strength of rock; 61 for RQD; 2 for spacing of discontinuities; 2 for the condition of discontinuities; and 17 for ground water.

A Study on the Uncertainty of the Classification of Rook Mass Rating (RMR 암반분류법의 불확정성에 관한 연구)

  • Lee Sang-Eun;Jun Sung-Kwon;Kang Sang-Jin
    • Tunnel and Underground Space
    • /
    • v.15 no.6 s.59
    • /
    • pp.441-451
    • /
    • 2005
  • It is the unavoidable problem that the RMR rock classification method has the uncertainty resulted from uncertain definition of measured value in RMR grade table, hence in this paper, the estimation of probability density function$(p{\cdot}d{\cdot}f)$ graph with the evaluation of continuos RMR and the Monte Carlo Simulation and statistic reasoning were carried out to evaluate the uncertainty quantitatively. Also, the modified RMR rock classification table was presented in order to apply the uncertainty of RMR to the practice, and then the design process of standard support pattern and the tunnel support material was proposed.

A hybrid method to compose an optimal gene set for multi-class classification using mRMR and modified particle swarm optimization (mRMR과 수정된 입자군집화 방법을 이용한 다범주 분류를 위한 최적유전자집단 구성)

  • Lee, Sunho
    • The Korean Journal of Applied Statistics
    • /
    • v.33 no.6
    • /
    • pp.683-696
    • /
    • 2020
  • The aim of this research is to find an optimal gene set that provides highly accurate multi-class classification with a minimum number of genes. A two-stage procedure is proposed: Based on minimum redundancy and maximum relevance (mRMR) framework, several statistics to rank differential expression genes and K-means clustering to reduce redundancy between genes are used for data filtering procedure. And a particle swarm optimization is modified to select a small subset of informative genes. Two well known multi-class microarray data sets, ALL and SRBCT, are analyzed to indicate the effectiveness of this hybrid method.

A Suggestion of In-situ Rock Mass Evaluation and Correlation between Rock Mass Classfication Methods (현장암반 평가에 관한 제안 및 암반분류법들간의 상관관계 고찰)

  • Kim, Hong-Pyo;Chang, Ho-Min;Kang, Choo-Won;Ko, Chin-Surk
    • Explosives and Blasting
    • /
    • v.28 no.2
    • /
    • pp.133-147
    • /
    • 2010
  • A Suggestion of In-situ Rock Mass Evaluation and Correlation between Rock Mass Classfication MethodsThe purpose of this study is to find out rock mass classification method which is practically applicable to a field and to consider a correlation between the new method and the old method. Rock mass is an aggregate of separated blocks. To express the aggregate, the properties of both intact rock and rock mass should be considered. In this study, therefore, parameters for rock mass description are classified into rock strength and rock structure. Indices for parameters evaluation are obtained from old method and the strength and structure property of rock is described by using those indices. Value of 25 is allocated to each parameter obtained. $RMR_{basic}$ =0.86(X=Method)+14.47 is derived between $RMR_{basic}$ and this study and $RMR^*$ = 0.87(X-Method)+9.20 is derived between revised RMR and this study. Coefficient of determination is $R^2$=0.841 and $R^2$=0.846 each.

A Study on the Characteristics of Rock Mass by GSI in Limestone Mine (석회석 광산에서의 GSI 분류법에 의한 암반특성연구)

  • ;Kaynnam U. M. Rao
    • Tunnel and Underground Space
    • /
    • v.14 no.2
    • /
    • pp.86-96
    • /
    • 2004
  • Rock mass classification methods such as RMR, Q system and GSl have been widely adopted with certain modifications for the design of mine openings. The GSI system is the only rock mass classification system that is related to Mohr-Coulomb and Hoek-Brown strength parameters and gives a simple method to calculate the engineering properties of rock masses which can be useful input parameters for a numerical analysis. A detailed surveying for GSI mapping as well as far calculating RMR values was undertaken at Daesung and Pyunghae underground limestone mining sites. RQD values were determined for row locations in these two mining sites. Based on GSI values and intact rock strength properties, the rock mass strength modulus of elasticity as well as the Mohr-Coulomb strength parameter c$_{m}$ and $\phi$$_{m}$ were determined. GSI and RMR are correlated.