结构面粗糙度系数与采样精度的关系研究
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摘要
结构面粗糙度系数(JRC)的获取过程中存在采样精度问题,为了获取合理的JRC值,本文开展了JRC剖面线采样点精度研究。选取3种岩石,每种取10个具有一定粗糙程度的结构面为研究对象,运用三维激光扫描技术获取结构面几何形貌特征并进行数字化处理。在此基础上,提取结构面选定剖面线的起伏信息,利用分形理论计算不同采样点间隔条件下剖面线的JRC值,分析JRC取值中存在的采样点间隔效应,并研究其影响因素。结果发现:JRC值受剖面线采样点间隔影响,当采样点间隔小于临界间隔值时,JRC值基本保持不变;当间隔大于临界间隔值时JRC值出现波动。采样点临界间隔值与结构面粗糙程度相关,与JRC值呈负指数函数关系,并且其关系受岩石类型影响,岩石颗粒越小两者拟合度越高。综合3种岩石得到JRC值与采样点临界间隔值关系服从y=1.8314e~(-0.067x)的函数分布,可以此为依据进行采样点临界间隔定量取值,来消除间隔效应对JRC值的影响。该项研究成果可为结构面粗糙信息采集提供科学的方法,通过选取合理的采样点数量,保证结构面信息采集工作效率和JRC值计算精度。
The roughness of rock structure plane affects its shear strength.The joint roughness coefficient(JRC) has been widely used as a roughness parameter.However,there are sampling precision problems existing in the acquisition of JRC values.In order to obtain reasonable JRC values,this paper conducts a study on the precision of JRC profile sampling.10 structure planes of sandstone,diorite and granite with a size of 10 cm·10 cm are selected as study objects,respectively.A hand-held 3 D laser scanner is used to scan the structure plane surface to obtain its geometric features.Digital processing is carried out with the help of 3 D morphological image post-processing software.On the basis of this,fractal theory is selected to calculate JRC values under different sampling point spacing conditions.Then sampling point interval effects on JRC value is analyzed and its influencing factors arestudied.Results show that:JRC values are affected mainly by the sample point interval on profile line.However,when the sampling interval is less than a certain critical value,the JRC basically remains unchanged.The critical interval of sampling point is related to the roughness of structural plane and has a negative exponential relation with the JRC values.In addition,the negative exponential relation is influenced by rock type.The smaller the rock particles are,the better the imitative effect is.When the three types of rock are considered comprehensively,a negative exponential function y = 1.8314 e-0.067 xis obtained between the critical interval of sampling point and JRC value.So,to remove the interval effects on the JRC evaluation,the critical interval of sampling points can be quantified according to the function.This study can provide a scientific method for the collection of roughness information of structural plane.And the precision and efficiency of structural plane information collection can be ensured by selecting a reasonable number of sampling points.
The roughness of rock structure plane affects its shear strength.The joint roughness coefficient(JRC) has been widely used as a roughness parameter.However,there are sampling precision problems existing in the acquisition of JRC values.In order to obtain reasonable JRC values,this paper conducts a study on the precision of JRC profile sampling.10 structure planes of sandstone,diorite and granite with a size of 10 cm·10 cm are selected as study objects,respectively.A hand-held 3 D laser scanner is used to scan the structure plane surface to obtain its geometric features.Digital processing is carried out with the help of 3 D morphological image post-processing software.On the basis of this,fractal theory is selected to calculate JRC values under different sampling point spacing conditions.Then sampling point interval effects on JRC value is analyzed and its influencing factors arestudied.Results show that:JRC values are affected mainly by the sample point interval on profile line.However,when the sampling interval is less than a certain critical value,the JRC basically remains unchanged.The critical interval of sampling point is related to the roughness of structural plane and has a negative exponential relation with the JRC values.In addition,the negative exponential relation is influenced by rock type.The smaller the rock particles are,the better the imitative effect is.When the three types of rock are considered comprehensively,a negative exponential function y = 1.8314 e-0.067 xis obtained between the critical interval of sampling point and JRC value.So,to remove the interval effects on the JRC evaluation,the critical interval of sampling points can be quantified according to the function.This study can provide a scientific method for the collection of roughness information of structural plane.And the precision and efficiency of structural plane information collection can be ensured by selecting a reasonable number of sampling points.
引文
Andrade P S,Saraiva A A.2008.Estimating the joint roughness coefficient of discontinuities found in metamorphic rocks[J].Bulletin of Engineering Geology and the Environment,67(3):425-434.
Bae D S,Kim K S,Koh Y K,et al.2011.Characterization of joint roughness in granite by applying the scan circle technique to images from a borehole televiewer[J].Rock Mechanics&Rock Engineering,44(4):497-504.
Barton N,Choubey V.1977.The shear strength of rock joints in theory and practice[J].Rock Mechanics,10:1-54.
Barton N.1973.Review of a new shear strength criterion for rock joints[J].Engineering Geology,7:579-602.
Ge Y F,Tang H M,Cheng H,et al.2015.Direct shear tests study for relationship between surface temperature and surface roughness of rock joints[J].Journal of Engineering Geology,23(4):624-633.
Gordon S,Lichti D,Stewart M.2001.Application of a high resolution,ground-based laser scanner for deformation measurements[C]//Proceedings of the 10th International FIG Symposium on Deformation Measurements.Orange:[s.n.]:23-32.
Guo S F,Qi S W,Li X X,et al.2016.Strength and deformation characteristics of rock sample with discontinuities under numerical uniaxial compression simulation tests[J].Journal of Engineering Geology,24(5):891-898.
He B S,Ding L Q,Sun P.2007.The application of 3-D laser scanning technology in rock joint sets identification[J].Journal of China Institute of Water Resources and Hydropower Research,5(1):43-48.
Jang H S,Kang S S,Jang B A.2014.Determination of Joint roughness coefficients using roughness parameters[J].Rock Mechanics&Rock Engineering,47(6):2061-2073.
Jiang J W,Xiang W,Joachimr R,et al.2012.Research on shear strength parameters of structural planes in rock mass based on threedimensional morphology spatial analysis and simulation tests[J].Chinese Journal of Rock Mechanics and Engineering,31(10):2127-2137.
Kulatilake P H S W,Um J,Pan G.1997.Requirements for accurate estimation of fractal parameters for self-affine roughness profiles using the line scaling method[J].Rock Mechanics&Rock Engineering,30(4):181-206.
Lee Y H,Carr J R,Barr D J,et al.1990.The fractal dimension as a measure of the roughness of rock discontinuity profiles[J].International Journal of Rock Mechanics&Mining Sciences&Geomechanics Abstracts,27(6):453-464.
Lemmens M.2011.Geo-information[M].Springer:101-121.
Li Y,Huang R.2015.Relationship between joint roughness coefficient and fractal dimension of rock fracture surfaces[J].International Journal of Rock Mechanics&Mining Sciences,75:15-22.
Mandelbrot B B.1977.Fractal;Form,Chance and Dimension[M].San Francisco:Freeman.
Mandelbrot B B.1983.The fractal geometry of nature/Revised and enlarged edition[J].New York:W.h.freeman&Co.
Mandelbrot B B,Passoja D E,Paullay A J.1984.Fractal character of fracture surfaces of metals[J].Nature,308:732-722.
Song L B,Jiang Q,Li Y H,et al.2017.Stability of statistical parameters of discontinuities morphology and anisotropy based on different sampling intervals[J].Rock and Soil Mechanics,38(4):1121-1132.
Tang Z C,Liu Q S,Xia C C.2015.Investigation of three-dimensional roughness scale-dependency and peak shear strength criterion[J].Journal of Central South University(Science and Technology),46(7):2524-2531.
Xia C C,Sun Z Q.2002.Engineering mechanics of rock joints[M].Shanghai:Tongji University Press:18-39.
Xia C C.1996.A study on the surface morphological feathers of rock structural faces[J].Journal of Engineering Geology,4(3):71-78.
Xie H P,Pariseau W G.1994.Fractal estimation of rock joint roughness[J].Science in China(Series B),24(5):524.
Xie H P.1995.Fractal description of rock joints[J].Chinese Journal of Geotechnical Engineering,17(1):18-22.
Xie H P.1996.An introdction of fractal methods on rock mechanics[M].Beijing:Science Press.
Yang Z Y,Di C C,Lo S C.2001.Two-dimensional hurst index of joint surfaces[J].Rock Mechanics&Rock Engineering,34(4):323-345.
Yin X M,Yan E C,Cui X J,et al.2017.Characteristic of strength anisotropy and failure modes of schist[J].Journal of Engineering Geology,25(4):943-952.
葛云峰,唐辉明,程昊,等.2015.基于直剪试验的岩体结构面表面温度与粗糙度关系研究[J].工程地质学报,23(4):624-633.
郭松峰,祁生文,李星星,等.2016.含结构面岩体试样单轴强度与变形特征[J].工程地质学报,24(5):891-898.
何秉顺,丁留谦,孙平.2007.三维激光扫描系统在岩体结构面识别中的应用[J].中国水利水电科学研究院学报,5(1):43-48.
江洎洧,项伟,Joachim R,等.2012.基于三维形态空间分析和仿真试验的岩体结构面剪切强度参数研究[J].岩石力学与工程学报,31(10):2127-2137.
宋磊博,江权,李元辉,等.2017.不同采样间隔下结构面形貌特征和各向异性特征的统计参数稳定性研究[J].岩土力学,38(4):1121-1132.
唐志成,刘泉声,夏才初.2015.节理三维形貌参数的采样效应与峰值抗剪强度准则[J].中南大学学报(自然科学版),46(7):2524-2531.
夏才初,孙宗颀.2002.工程岩体节理力学[M].上海:同济大学出版社:18-39.
夏才初.1996.岩石结构面的表面形态特征研究[J].工程地质学报,4(3):71-78.
谢和平,Pariseau W G.1994.岩石节理粗糙系数(JRC)的分形估计[J].中国科学(B辑),24(5):524.
谢和平.1995.岩石节理的分形描述[J].岩土工程学报,17(1):18-23.
谢和平.1996.分形-岩石力学导论[M].北京:科学出版社.
尹晓萌,晏鄂川,崔学杰,等.2017.片岩强度各向异性特征及破坏模式分析[J].工程地质学报,25(4):943-952.
Bae D S,Kim K S,Koh Y K,et al.2011.Characterization of joint roughness in granite by applying the scan circle technique to images from a borehole televiewer[J].Rock Mechanics&Rock Engineering,44(4):497-504.
Barton N,Choubey V.1977.The shear strength of rock joints in theory and practice[J].Rock Mechanics,10:1-54.
Barton N.1973.Review of a new shear strength criterion for rock joints[J].Engineering Geology,7:579-602.
Ge Y F,Tang H M,Cheng H,et al.2015.Direct shear tests study for relationship between surface temperature and surface roughness of rock joints[J].Journal of Engineering Geology,23(4):624-633.
Gordon S,Lichti D,Stewart M.2001.Application of a high resolution,ground-based laser scanner for deformation measurements[C]//Proceedings of the 10th International FIG Symposium on Deformation Measurements.Orange:[s.n.]:23-32.
Guo S F,Qi S W,Li X X,et al.2016.Strength and deformation characteristics of rock sample with discontinuities under numerical uniaxial compression simulation tests[J].Journal of Engineering Geology,24(5):891-898.
He B S,Ding L Q,Sun P.2007.The application of 3-D laser scanning technology in rock joint sets identification[J].Journal of China Institute of Water Resources and Hydropower Research,5(1):43-48.
Jang H S,Kang S S,Jang B A.2014.Determination of Joint roughness coefficients using roughness parameters[J].Rock Mechanics&Rock Engineering,47(6):2061-2073.
Jiang J W,Xiang W,Joachimr R,et al.2012.Research on shear strength parameters of structural planes in rock mass based on threedimensional morphology spatial analysis and simulation tests[J].Chinese Journal of Rock Mechanics and Engineering,31(10):2127-2137.
Kulatilake P H S W,Um J,Pan G.1997.Requirements for accurate estimation of fractal parameters for self-affine roughness profiles using the line scaling method[J].Rock Mechanics&Rock Engineering,30(4):181-206.
Lee Y H,Carr J R,Barr D J,et al.1990.The fractal dimension as a measure of the roughness of rock discontinuity profiles[J].International Journal of Rock Mechanics&Mining Sciences&Geomechanics Abstracts,27(6):453-464.
Lemmens M.2011.Geo-information[M].Springer:101-121.
Li Y,Huang R.2015.Relationship between joint roughness coefficient and fractal dimension of rock fracture surfaces[J].International Journal of Rock Mechanics&Mining Sciences,75:15-22.
Mandelbrot B B.1977.Fractal;Form,Chance and Dimension[M].San Francisco:Freeman.
Mandelbrot B B.1983.The fractal geometry of nature/Revised and enlarged edition[J].New York:W.h.freeman&Co.
Mandelbrot B B,Passoja D E,Paullay A J.1984.Fractal character of fracture surfaces of metals[J].Nature,308:732-722.
Song L B,Jiang Q,Li Y H,et al.2017.Stability of statistical parameters of discontinuities morphology and anisotropy based on different sampling intervals[J].Rock and Soil Mechanics,38(4):1121-1132.
Tang Z C,Liu Q S,Xia C C.2015.Investigation of three-dimensional roughness scale-dependency and peak shear strength criterion[J].Journal of Central South University(Science and Technology),46(7):2524-2531.
Xia C C,Sun Z Q.2002.Engineering mechanics of rock joints[M].Shanghai:Tongji University Press:18-39.
Xia C C.1996.A study on the surface morphological feathers of rock structural faces[J].Journal of Engineering Geology,4(3):71-78.
Xie H P,Pariseau W G.1994.Fractal estimation of rock joint roughness[J].Science in China(Series B),24(5):524.
Xie H P.1995.Fractal description of rock joints[J].Chinese Journal of Geotechnical Engineering,17(1):18-22.
Xie H P.1996.An introdction of fractal methods on rock mechanics[M].Beijing:Science Press.
Yang Z Y,Di C C,Lo S C.2001.Two-dimensional hurst index of joint surfaces[J].Rock Mechanics&Rock Engineering,34(4):323-345.
Yin X M,Yan E C,Cui X J,et al.2017.Characteristic of strength anisotropy and failure modes of schist[J].Journal of Engineering Geology,25(4):943-952.
葛云峰,唐辉明,程昊,等.2015.基于直剪试验的岩体结构面表面温度与粗糙度关系研究[J].工程地质学报,23(4):624-633.
郭松峰,祁生文,李星星,等.2016.含结构面岩体试样单轴强度与变形特征[J].工程地质学报,24(5):891-898.
何秉顺,丁留谦,孙平.2007.三维激光扫描系统在岩体结构面识别中的应用[J].中国水利水电科学研究院学报,5(1):43-48.
江洎洧,项伟,Joachim R,等.2012.基于三维形态空间分析和仿真试验的岩体结构面剪切强度参数研究[J].岩石力学与工程学报,31(10):2127-2137.
宋磊博,江权,李元辉,等.2017.不同采样间隔下结构面形貌特征和各向异性特征的统计参数稳定性研究[J].岩土力学,38(4):1121-1132.
唐志成,刘泉声,夏才初.2015.节理三维形貌参数的采样效应与峰值抗剪强度准则[J].中南大学学报(自然科学版),46(7):2524-2531.
夏才初,孙宗颀.2002.工程岩体节理力学[M].上海:同济大学出版社:18-39.
夏才初.1996.岩石结构面的表面形态特征研究[J].工程地质学报,4(3):71-78.
谢和平,Pariseau W G.1994.岩石节理粗糙系数(JRC)的分形估计[J].中国科学(B辑),24(5):524.
谢和平.1995.岩石节理的分形描述[J].岩土工程学报,17(1):18-23.
谢和平.1996.分形-岩石力学导论[M].北京:科学出版社.
尹晓萌,晏鄂川,崔学杰,等.2017.片岩强度各向异性特征及破坏模式分析[J].工程地质学报,25(4):943-952.