• Title/Summary/Keyword: RMR & Q

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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
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    • v.35 no.4
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    • pp.27-35
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    • 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.

Analysis of Acquaintance Relations Between Parameters of RMR and Q Rock Mass Classification System (RMR 및 Q 암반분류법의 평가 요소간 친숙도 관계 분석)

  • Synn, Joong-Ho;Park, Chul-Whan;SunWoo, Choon
    • Tunnel and Underground Space
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    • v.18 no.6
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    • pp.408-417
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    • 2008
  • Rock mass classification methods such as RMR and Q system have different characteristics each other in parameters considered and applications, and so it is very important to prescribe the relationship between parameters for the analysis of correlativity of these methods. With the Held data of RMR and Q estimation in road construction sites, the acquaintance relations between RMR and Q of rock mass classifications are analyzed. The correlation equations between parameters of RMR and Q, matrix of correlation coefficients and the generalized form of acquaintance relation matrix are derived. This acquaintance relation matrix can be further extended to the form of generalized acquaintance relation network, and could be used to analyze the correlativity and to enhance the utility of common rock mass classification methods.

A Study on Relationship Between RMR and Q System in Rock Mass Classification (암반분류에서 RMR과 Q System의 상관성 분석)

  • 안종필;박주원;박상도
    • Proceedings of the Korean Geotechical Society Conference
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    • 2000.11a
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    • pp.737-744
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    • 2000
  • This paper resorts to rock mass rating and rock mass quality to draw value based on the evaluation of rock and to draw interrelation formula in relation to rock mass quality, A comparative analysis was given of survey values reported in the existing documents. This paper has tried to find out the relationship between RMR and Q System for the sake of choosing rational reinforcing patterns and of the safety of tunnels. The results run as follow: RMR=8.251n(Q)+43.83. This paper has also tried to find out the relationship between RMR and Q System by using Fuzzy Approximate Reasoning Concept. We suggest that those in charge should not depend on a single system only after evaluating the classification of rocks, and compare one result with another for the good of keeping track of the condition of base rocks in a better way.

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A Case Study for Evaluating Groundwater Condition in RMR and Q Rock Mass Classification on Bard Rock Tunnel (RMR 및 Q 분류시 지하수 조건 평가방법에 관한 사례 연구)

  • 이대혁;이철욱;김호영
    • Tunnel and Underground Space
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    • v.13 no.5
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    • pp.353-361
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    • 2003
  • For RMR and Q rock mass classification at the design and construction stage, evaluation of groundwater condition is usually based upon the experience due to the restriction of available methods. Based on the results of Taejon LNG Pilot Cavern which acquire joint water pressure, inflow rate of ground water and hydraulic conductivity model, estimates from numerical analysis and analytical solutions were compared to verify each evaluation method. As the result, the Raymer(2001) approach was found to be efficient for estimating inflow rate and corresponding value.

Evaluating the Stability of Large-scale Gangways Mined in a Limestone Mine Using Rock Classification Schemes (암반분류법을 이용한 석회석 광산 내 대규격 갱도의 안정성 평가)

  • Yoon, Yong-Kyun;Lee, Hong-Woo
    • Tunnel and Underground Space
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    • v.17 no.6
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    • pp.503-510
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    • 2007
  • Rock classification schemes such as RMR, Q-system were applied to investigate the stability of large-scale gangways mined in a limestone mine. 22 areas for engineering geological surveys were selected and rock classifications at each survey point had been carried out. Considering the fact that the observed gangways have not experienced some severe failure and have been stably maintained till now, it is found that Q-system is more reasonable than RMR in evaluating the stability of unsupported span. Also, extended Mathews stability graph method which is a kind of revised Q-system was used to assess the stability of gangways and the results represent that all gangways except for one area are under stable condition. Based on above the mentioned results, the empirical equations to design the maximum unsupported span and critical height of a large-scale gangway are suggested.

Designing of the Beheshtabad water transmission tunnel based on the hybrid empirical method

  • Mohammad Rezaei;Hazhar Habibi
    • Structural Engineering and Mechanics
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    • v.86 no.5
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    • pp.621-633
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    • 2023
  • Stability analysis and support system estimation of the Beheshtabad water transmission tunnel is investigated in this research. A combination approach based on the rock mass rating (RMR) and rock mass quality index (Q) is used for this purpose. In the first step, 40 datasets related to the petrological, structural, hydrological, physical, and mechanical properties of tunnel host rocks are measured in the field and laboratory. Then, RMR, Q, and height of influenced zone above the tunnel roof are computed and sorted into five general groups to analyze the tunnel stability and determine its support system. Accordingly, tunnel stand-up time, rock load, and required support system are estimated for five sorted rock groups. In addition, various empirical relations between RMR and Q i.e., linear, exponential, logarithmic, and power functions are developed using the analysis of variance (ANOVA). Based on the significance level (sig.), determination coefficient (R2) and Fisher-test (F) indices, power and logarithmic equations are proposed as the optimum relations between RMR and Q. To validate the proposed relations, their results are compared with the results of previous similar equations by using the variance account for (VAF), root mean square error (RMSE), mean absolute percentage error (MAPE) and mean absolute error (MAE) indices. Comparison results showed that the accuracy of proposed RMR-Q relations is better than the previous similar relations and their outputs are more consistent with actual data. Therefore, they can be practically utilized in designing the tunneling projects with an acceptable level of accuracy and reliability.

Empirical Equations for Rock Mass Classifications and Rock Property Evaluations (지반정수산정을 위한 경험적 암반평가기법과 상관성)

  • 신중호;신희순
    • Proceedings of the Korean Geotechical Society Conference
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    • 2002.03a
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    • pp.79-86
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    • 2002
  • Rock mass classifications form the back bone of the empirical design approach and are widely employed in rock engineering. In this paper the inter-relations were discussed among RMR, Q-system, RCR, N, M-RMR, RMi, and L-RMR. Several relationships for the assessment of the modulus of deformation of rock mass, Poisson's ratio, uniaxial compressive strength, tensile strength, cohesion and internal friction angle were also analysed and suggested.

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Introduction of Q-slope and its Application Case in a Open Pit Coal Mine (Q-slope의 소개와 노천채탄장에서의 적용 사례)

  • Sunwoo, Choon
    • Tunnel and Underground Space
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    • v.29 no.5
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    • pp.305-317
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    • 2019
  • The RMR and Q-system for characterizing rock mass and drilling core, and for estimating the support and reinforcement measures in mine galleries, tunnels and caverns have been widely used by engineers. SMR has been widely used in the rock mass classification for rock slope, but Q-Slope has been introduced into slopes since 2015. In the last ten years, a modified Q-system called Q-slope has been tested by the many authors for application to the benches in open pit mines and excavated road rock slopes. The results have shown that a simple correlation exists between Q-slope values and the long-term stable and unsupported slope angles. Just as RMR and Q have been used together in a tunnel or underground space and complemented by comparison, Q-Slope can be used in parallel with SMR. This paper introduces how to use Q-Slope which has not been announced in Korea and application examples of Pasir open pit coal mine in Indonesia.

A Case Study for Evaluating Jw in RMR and Q Rock Mass Classification on Hard Rock Tunnel (RMR 및 Q 분류시 Jw 선정방법에 관한 사례 연구)

  • 이대혁;이철욱;김호영
    • Proceedings of the Korean Geotechical Society Conference
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    • 2003.06b
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    • pp.67-81
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    • 2003
  • 터널 설계 조사단계 및 시공중 RMR 및 Q분류를 시행하고자 하는 경우, 여러 가지 제약조건으로 말미암아 지하수 조건에 해당하는 항목인 Jw의 선정은 조사자의 경험에 의존하고 있다. Jw 선정시에는 되도록 정량적인 선정이 가능한 지하수 유입량 자료에 기초하는 것이 바람직하기 때문에, 본 고에서는 여러 가지 예측방법을 검증함으로서 보다 합리적인 방법을 제안하고자 한다. 절리수두, 지하수 유입량, 수리전도도 특성 등의 다양한 자료를 구한 대전 LNG Pilot Cavern의 결과를 바탕으로 수치해석 결과, 이론식에 의한 결과를 측정결과와 상호 비교하였다. 그 결과 합리적인 수리전도도 모델을 선정할 수 있다면 이론식으로도 Jw값을 비교적 근사하게 선정할 수 있다는 사실을 제안하였다.

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Study on the Geotechnical Characteristics of Granite in Korea and their Correlation with Rock Classification Method (국내 화강암의 지반공학적 특성 및 암반분류법과의 상관성에 관한 연구)

  • SunWoo, Choon;Ryu, Dong-Woo;Kim, Hyung-Mok;Kim, Ki-Seog
    • Tunnel and Underground Space
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    • v.21 no.3
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    • pp.205-215
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    • 2011
  • In this study, we analyzed physical properties of granites and their correlation with rock mass classification methods. The granite samples were obtained from field survey, in-situ borehole tests and laboratory tests for a design phase of various roads, railways and other civil engineering works in Korea. Among the measured physical properties, the results of unit weight, compressive strength, tensile strength, seismic velocity, cohesion, friction angle, elastic modulus and deformation modulus were introduced. We also correlated these properties with the compressive strength. The results of different rock classification method of RQD, RMR, and Q-system against the granites in Korea were compared with each other, and the correlation equations were proposed in a more simplified form. We also derived RMR values using the compressive strength as well as the RQD values of in-situ drilled cores, and estimated the deformation modulus of in-situ rock mass in terms of the RMR values.