张国彪, 包含, 兰恒星, 晏长根, 陶悦. 2018: 结构面粗糙度系数与采样精度的关系研究. 工程地质学报, 26(5): 1336-1341. DOI: 10.13544/j.cnki.jeg.2018248
    引用本文: 张国彪, 包含, 兰恒星, 晏长根, 陶悦. 2018: 结构面粗糙度系数与采样精度的关系研究. 工程地质学报, 26(5): 1336-1341. DOI: 10.13544/j.cnki.jeg.2018248
    ZHANG Guobiao, BAO Han, LAN Hengxing, YAN Changgen, TAO Yue. 2018: RESEARCH ON THE RELATIONSHIP BETWEEN JOINT ROUGHNESS COEFFICIENT AND SAMPLING PRECISION OF STRUCTURAL PLANE. JOURNAL OF ENGINEERING GEOLOGY, 26(5): 1336-1341. DOI: 10.13544/j.cnki.jeg.2018248
    Citation: ZHANG Guobiao, BAO Han, LAN Hengxing, YAN Changgen, TAO Yue. 2018: RESEARCH ON THE RELATIONSHIP BETWEEN JOINT ROUGHNESS COEFFICIENT AND SAMPLING PRECISION OF STRUCTURAL PLANE. JOURNAL OF ENGINEERING GEOLOGY, 26(5): 1336-1341. DOI: 10.13544/j.cnki.jeg.2018248

    结构面粗糙度系数与采样精度的关系研究

    RESEARCH ON THE RELATIONSHIP BETWEEN JOINT ROUGHNESS COEFFICIENT AND SAMPLING PRECISION OF STRUCTURAL PLANE

    • 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。

       

      Abstract: 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 3D laser scanner is used to scan the structure plane surface to obtain its geometric features. Digital processing is carried out with the help of 3D 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 are studied. 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=1.8314e-0.067x is 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.

       

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