裂隙张开度测量的改进中轴算法及应用研究

Improved axis algorithm for measurement of fracture aperture and its application

裂隙张开度是决定裂隙岩体渗透特性的关键因素,其分布特点的精确获取对科学评价裂隙岩体的渗透特性具有重要意义。由于裂隙形态复杂多样,传统测量方法在获取裂隙张开度时存在一定局限性。为了更加准确高效地测量裂隙张开度,在总结前人测量方法的基础上,改进了多边形中轴算法,并从张开度的定义出发,将其运用于裂隙张开度的测量。采用该改进方法对某高放废物处置库候选场址典型断裂带碎裂岩中3种不同类型裂隙的张开度分布进行测量,同时对比最小外接矩形法及中心线法的测量结果。对比发现,改进的张开度中轴算法较传统算法原理简单,易于编程实现,测量结果精度更高,且对不同形态裂隙的张开度测量适用性好,从而验证了该方法的有效性和实用性。研究方法为裂隙张开度的准确测量提供了一种新的切实可行的途径。

The fracture aperture affects the permeability of fractured rock mass greatly. It is significant for characterizing the inner structure and evaluating the permeability of fractured rock. However,as the morphology of fracture in nature is diverse and complex,the traditional aperture measurements have some limits when measuring the aperture. In order to measure the fracture aperture more accurately and efficiently,on the basis of summarizing and analyzing the methods of fracture aperture measurement proposed by the former researchers,an improved Central Axis Algorithm of Aperture according to the definition of the fracture aperture was proposed. In order to validate the reliability and practicability of this method,three typical fractures with different morphological complexity were collected from the cataclasite in the fault zone of a high-level radioactive waste repository candidate site,and their fractures were measured by the CAAA. Compared with the results obtained by two other traditional measurement methods,the Minimum Enclosing Rectangle Algorithm and the Central Line Algorithm,the CAAA result is closer to the real condition,which proves that the CAAA is simple in principle and easy to programming,and has high reliability and applicability.Therefore,the proposed method provides a new practical way to accurately measure the fracture aperture.