岩石节理三维表面形貌精细描述与粗糙度定量确定方法的研究

Precise description of rock joints' 3D superficial morphology and the quantitative determination of 3D joint roughness coefficient

为了实现对岩石节理粗糙度进行定量描述,分析目前已有研究方法和理论存在的局限性,参考有关岩石节理剪切机制的研究后,提出12个反映节理表面剪切特性与各向异性的三维粗糙度特征参数。并且,基于三维高精度激光扫描与GIS技术,以似斑状花岗岩为例,对其节理表面起伏形态进行精确测定,实现了对三维特征参数的提取。通过对具有明显阶坎或凸起(凹坑)状起伏形态岩石节理的粗糙特性进行精确定向描述基础后,发现大于45°的倾斜面面积对剪切方向的敏感性较大。最终,通过对多个节理样本的室内直剪试验与测量结果的分析,得到了3DJRC的经验计算公式。

In view of the limits on existing 2D evaluation methods,twelve 3D joint roughness characteristic parameters were proposed to quantitatively evaluate the roughness of rock joints.Those 3D parameters can not only reflect shear characteristics of asperities but incorporate the anisotropy of joint surfaces.Then,using 3D laser scanning and GIS technology,it is found that the digital geometric model of joints can be successfully obtained,then all the value of 3D joint parameters can be precisely calculated.This method was first applied to analyzing the roughness of a typical rock joint surface,on which there were scarps,bulges and pits.Results shows that the area of inclines larger than 45°has a high sensitivity to shear direction.Finally,a series of direct shear tests on natural joint samples were conducted to get the empirical formula of 3 DJRC.