• Title/Summary/Keyword: 불연속면 거칠기

Search Result 18, Processing Time 0.021 seconds

Evaluation of Rock Discontinuity Roughness Anisotropy based on Digital 3D Point Cloud Data (디지털 3차원 점군데이터 기반 암반 불연속면 거칠기 이방성 평가)

  • Taehyeon Kim;Kwang Yeom Kim
    • Tunnel and Underground Space
    • /
    • v.33 no.6
    • /
    • pp.495-507
    • /
    • 2023
  • The roughness of discontinuity significantly influences the mechanical characteristics of rock masses and extensively affects thermal and hydraulic behaviors. In this study, we utilized photogrammetry to generate 3D point cloud data for discontinuity and applied this data to characterize the roughness of discontinuity. The discontinuity profiles, reconstructed from the 3D point cloud data, were compared with those manually measured using a profile gauge. This comparison served to validate the accuracy and reliability of the acquired point cloud data in replicating the actual configurations of rock surfaces. Subsequent to this validation, influence of the number of profiles for representative JRC assessment was further investigated followed by suggestion of roughness anisotropy evaluation method with application of it to actual rock discontinuity surfaces.

Shear Deformation and Failure Characteristics of Rock-Concrete Discontinuities (암석-콘크리트 불연속면의 전단변형 및 파괴특성에 관한 연구)

  • 홍창우;전석원;황대진;최해문;박의섭
    • Proceedings of the Korean Geotechical Society Conference
    • /
    • 2001.03a
    • /
    • pp.57-64
    • /
    • 2001
  • 암석-콘크리트 불연속면의 전단변형 및 파괴특성을 규명하기 위해 상부 재료를 콘크리트로, 하부 재료를 암석으로 하는 규칙.불규칙 톱니형 시료와 인공 절리시료를 제작하여 실험실 직접전단시험을 실시하였다. 전단과정 동안 하중과 변위 외에 미소파괴음의 계수와 에너지를 측정하여 전단과정의 단계별 특징을 규명하였고 미소파괴음 음원추적을 실시하여 불연속면에서의 거칠기 파괴부분의 변화를 고찰하였다. 또한 암석 불연속면과 암석-콘크리트 불연속면의 거동을 비교하고 거칠기의 불규칙성 증가에 따른 전단거동의 변화를 관찰하였다.

  • PDF

A Study on the Quantification of Assessment Category of Roughness of Discontinuity of Rock Mass Classification Using Delphi method (델파이방법을 이용한 암반분류법의 불연속면 거칠기 평가분류 정량화에 관한 연구)

  • Kim, Byung-Ryeol;Lee, Seung-Joong;Choi, Sung-Oong
    • Tunnel and Underground Space
    • /
    • v.25 no.2
    • /
    • pp.210-219
    • /
    • 2015
  • This paper describes a new quantitative process for evaluating the roughness of discontinuity, which is suggested as a qualitative criteria in RMR or Q-system. For this purpose, the Delphi method which is one of the surveying methods was introduced. The selected panels were asked to evaluate the roughness of discontinuities on the Web which was hosted by authors in advance. A total of 3 surveys were performed using JRCs suggested by Barton and Choubey as well as Ai generated by the Monte Carlo simulations. After each survey, the results were provided to all panels for comparing their decisions to others. As surveys proceeded, better consensus and convergence were achieved. With a good agreement of panels on roughness classification, the quantitative criteria for roughness of discontinuity in RMR and Q-system was established in this study.

A Numerical Study of the Shear Behavior of a Rock Joint Considering Quantitative Roughness Parameters (정량적인 거칠기 파라미터를 고려한 절리면 전단거동의 수치해석)

  • 김대복;손봉기;이정인
    • Journal of the Korean Geotechnical Society
    • /
    • v.17 no.4
    • /
    • pp.279-288
    • /
    • 2001
  • 암반내에 존재하는 불연속면은 지하구조물의 안정성에 큰 영향을 미친다. 불연속면을 해석하기 위한 구성법칙에 대한 많은 연구가 진행되어 왔으나, 객관적인 거칠기 파라미터를 이용한 전단거동 모사에 관한 연구는 아직 미흡한 실정이다. 본 연구에서는 정량적인 거칠기 파라미터를 이용한 두 가지의 새로운 구성방정식을 만들어 절리 거동을 모사하였다. 첫 번째 구성법칙은 탄소성 이론에 근거하여 두께가 없는 개별절리요소 이용한 방법이고, 두 번째 구성법칙은 3차원 레이저 변위 측정 데이터를 직접 이용하여 Ohnishi가 제안한 거칠기 손상모델을 도입하였다. 제안된 두 모델을 가지고 직접 전단시험을 모사해본 결과 실제 실험에 나타나는 변형률 경화 및 연화현상 그리고 잔류전단강도와 같은 현상을 볼 수 있었다.

  • PDF

Three-Dimensional Information Extraction of Discontinuity on Rock Slope by Processing Stereo Digital Images (입체 디지털 영상처리에 의한 암반사면의 불연속면에 대한 3차원 정보 추출)

  • Lee Dong-Cheon;Woo Ik;Choi Jin Ok
    • Economic and Environmental Geology
    • /
    • v.38 no.4 s.173
    • /
    • pp.369-380
    • /
    • 2005
  • This study describes image-based approach for efficient and objective evaluation method of the rock slope stability. Three-dimensional rock slope model was reconstructed by processing stereo digital images. The model provided fundamental information for geospatial analysis of the rock slope. Methods to extract three-dimensional information about discontinuity on the rock slope and to estimate roughness of the rock surfaces were suggested. The results show that stereo digital images have potential to provide information for both quantitative and qualitative analysis of rock slope. In addition, visualization of the results increases efficiency and benefit in evaluating rock slope stability.

Probabilistic Analysis for Rock Slope Stability Due to Weathering Process (풍화작용에 따른 암반사면 안정성의 확률론적 해석)

  • Park, Hyuck-Jin;Woo, Ik;Um, Jeong-Gi
    • Economic and Environmental Geology
    • /
    • v.42 no.4
    • /
    • pp.357-366
    • /
    • 2009
  • Since weathering weakens the rock fabric and exaggerates any structural weakness, it affects mechanical properties as well as physical and chemical properties of rock. Weathering leads to a decrease in density, strength, friction angle and cohesion, and subsequently it affects negatively on the stability of rock slope. The purpose of the study is to investigate the changes of the rock slope stability caused by discontinuities which have different weathering grades. For that, the discontinuity samples which are divided into two different weathering grades are obtained from the field and tested their mechanical properties such as JCS, JRC and residual friction angle. In order to evaluate the effects on the stability of slope due to weathering, the deterministic analysis is carried out. That is, the factors of safety for planar failure are calculated for rock masses which have two different weathering grades, such as fresh and weathered rock mass. However, since the JRC and friction angle values are widely scattered and the deterministic analysis cannot consider the variation, the factors of safety cannot represent properly the stability of the rock slope. Therefore, the probabilistic analysis has been used to consider the scattered values. In the deterministic analysis, the factors of safety for the fresh discontinuity and weathered discontinuity are 1.25 and 1.0, respectively. The results indicate the fresh discontinuities are stable for planar failure and the weathered discontinuities are marginally stable. However, the probabilities of failure for the fresh discontinuity and weathered discontinuity are 25.6% and 45.9%, respectively. This shows that both discontinuities are analyzed as unstable in the probabilistic analysis.

Measurement of Joint-Orientation and Monitoring of Displacement in Tunnel using 3D Laser Scanning System (3차원 레이저 스캐닝 시스템을 이용한 불연속면의 방향성 측정과 터널 변위 모니터링)

  • Shon, Ho-Woong;Oh, Seok-Hoon;Kim, Young-Kyung
    • Journal of the Korean Geophysical Society
    • /
    • v.9 no.1
    • /
    • pp.47-62
    • /
    • 2006
  • More than 70% of Korean Peninsula is consisted of mountains, so that lots of roads, rail-roads and tunnel,which play a pivotal role in the industry activity, are existed along the rock-slope and in the rock-mass. Thus,it is urgent that tegration of management system through the optimum survey and design of rock-slope excavation, proper stabilization method and database of rock-slope. However, conventional methods have shortcoming with the economy of survey time and human resources, and the overcome of difficulties of approach to the in-situ rock-slope. To overcome the limitation of conventional method, this paper proposed the development of remote measurement system using Terrestrial Laser Scanning System. The method using Terrestrial 3D Laser Scanning System, which can get 3D spatial information on the rock-slope and2)Dept. Geosystem Engineering, Kangwon National University, Korea tunnel, has an advantage of reduction of measurement time and the overcome of difficulties of approach to the in-situ rock-slope/dam/tunnel. In the case of rock-slope, through the analysis of 3D modeling of point-cloud by Terrestrial Laser Scanning System, orientation of discontinuity, roughness of joint surface, failure shape and volume were successively achieved. in the case of tunnel face, through reverse-engineering, monitoring of displacement was possible.

  • PDF

Characterization of Fracture Roughness in Coarse.medium.fine Grained Granite (암반 불연속면의 거칠기 특성 - 조.중.세립질 화강암을 중심으로 -)

  • 김종태;정교철;김만일;송재용;박창근
    • The Journal of Engineering Geology
    • /
    • v.14 no.2
    • /
    • pp.147-168
    • /
    • 2004
  • Purpose of this study is to quantitatively characterize the fracture roughness which was measured with a confocal laser scanning microscope. The roughness discrete data measured by confocal laser microscope were analyzed by spectral analysis and fast Fourier transform (FFT).The roughness data by used noise reduction filter were applied for fractal analysis to describe roughness features quantitatively. Artificial fractures created by Brazilian test on granites were used to measure fracture roughness under the confocal laser scanning microscope. Measurements were performed along three scan lines on each fracture surface. 36 scan lines were determined on 12 specimens in total. Features of roughness showed that coarse and medium grained granites tend to more rough features than those of fine grained granites. Continuous analog data of roughness is possible to described as discrete data of measure roughness with a fixed interval under the confocal laser microscope. Results of FFT with the measured data showed the highest values on the second harmonics. Distribution of average amplitude of second harmonics was observed 0.9853 in coarse grained granite, 1.0792 in medium grained granite and 0.6794 in fine grained granite. This indicates that the larger roughness has the higher energy of harmonics as the result of fractal analysis in low frequency zone.

A Study of Roughness Measurement of Rock Discontinuities Using a Confocal Laser Scanning Microscope (콘포컬 레이저 현미경을 이용한 불연속면의 거칠기 측정 연구)

  • Byung Gon Chae;Jae Yong Song;Gyo Cheol Jeong
    • The Journal of Engineering Geology
    • /
    • v.12 no.4
    • /
    • pp.405-419
    • /
    • 2002
  • Fracture roughness of rock specimens is observed by a new confocal laser scanning microscope (CLSM; Olympus OLS1100). The wave length of laser is 488 nm, and the laser scanning is managed by a light polarization method using two galvano-meter scanner mirrors. The function of laser reflection auto-focusing enables us to measure line data fast and precisely. The system improves resolution in the light axis (namely z) direction because of the confocal optics. Using the CLSM, it is Possible to measure a specimen of the size up to $10{\;}{\times}{\;}10{\;}cm$ which is fixed on a specially designed stage. A sampling is managed in a spacing $2.5{\;}\mu\textrm{m}$ along x and y directions. The highest measurement resolution of z direction is $10{\;}\mu\textrm{m}$, which is more accurate than other methods. Core specimens of coarse and fine grained granite are provided. Fractures are artificially maneuvered by a Brazilian test method. Measurements are performed along three scan lines on each fracture surface. The measured data are represented as 2-D and 3-D digital images showing detailed features of roughness. Line profiles of the coarse granites represent more frequent change of undulation than those of the fine granite. Spectral analyses by the fast Fourier transform (FFT) are performed to characterize the roughness data quantitatively and to identify influential frequency of roughness. The FFT results suggest that a specimen loaded by large and low frequency energy tends to have high values of undulation change and large wave length of fracture roughness.