岩体结构面三维粗糙度评价的新方法

 为了获得具有明确几何意义及理论依据的岩体结构面粗糙度评价指标，结合结构面剪切破坏机制，阐明将结构面潜在接触部分作为粗糙度评价重要因素的理论依据；将结构面粗糙度评价指标与其力学性质建立联系，提出描述结构面三维粗糙程度的新参数–粗糙度指标 。 即岩体结构面的潜在接触部分在垂直于剪切方向的面的投影面积与结构面水平投影面积之比， 体现了结构面在剪切方向的三维几何信息，具有各向异性。基于三维激光扫描技术及Matlab编程，实现了结构面三维几何模型的建立及 的计算。以工程应用实例，展示 的计算过程；研究同一结构面不同精细程度的几何模型的 ，结果表明：基于 评价的结构面粗糙度具有各向异性，且同一剪切方向的结构面 随其几何模型精细程度的增强而增大。对比研究 与Grasselli粗糙度评价方法，结果表明基于此2种方法的粗糙度评价结果具有相似性。此外， 可与结构面抗剪强度建立一定联系，为结构面抗剪强度估算模型的进一步研究奠定了基础。

A new method for evaluating the roughness of three-dimensional discontinuity surface of rock

The reason of taking the potential contact area of rock mass discontinuity(RMD) as the important factor of surface roughness evaluation was explained theoretically in order to obtain the evaluation index with a clear geometric meaning. was put forward as a new evaluation index，which was associated with the mechanical properties. Two projection areas of the RMD surface were calculated，one was the projection of potential contact area on the plane which was perpendicular to the shear direction，the other was the projection of the whole RMD surface on the horizontal plane. is the area ratio of the former to the latter. The three-dimensional(3D) geometry information of the RMD in the shear direction was embodied by ，which was an anisotropic index. Based on the 3D laser scanning technology and Matlab programming，the 3D geometric model of the RMD was built and was calculated. The computational process and anisotropy of were presented via the engineering examples. A series of of the RMD models built with different elaborate degrees were studied，and the results showed that increased with the increasing of the elaborate degrees of models. The comparison between the results from Grasselli?s evaluation method and method showed that these two methods are similar. Furthermore，a good relationship was established between and the shear strength of the RMD，which laid the foundation for further study on the shear strength evaluation model of the RMD.