Studying the rough structure characteristics of rock fracture surfaces under microwave irradiation is of a great significance for understanding the rock-breaking mechanism. Therefore, this work takes fracture surface as the research object under three failure modes: microwave irradiation, uniaxial loading and microwave-uniaxial loading. The undulation and roughness are used to describe the morphological characteristics of the fractured surface. Research shows that the fracture surface under microwave irradiation is the smoothest, which exhibits undulation and rough fractal dimension in the range of 1–7$$mm and 2.0005–2.0657, respectively. The fractal anisotropy of the fracture surface is the most obvious under microwave irradiation. The roughness along the fracture surface is about 1.02 times that is perpendicular to the fracture direction. In the perspective of size effect characteristics, the roughness of the fracture surface under microwave irradiation shows a positive correlation with the selected size. The results provide a certain basis for interpreting the mechanism of microwave rock breaking.

研究微波辐照下岩石断裂面的粗糙结构特征对于理解岩石破碎机理具有重要意义。因此，本工作以微波辐照、单轴加载和微波单轴加载三种失效模式下的断裂面为研究对象。起伏度和粗糙度用来描述断裂表面的形态特征。研究表明，微波辐照下的断口表面最光滑，呈现出起伏，分形维数在1~7范围内$$毫米和2.0005-2.0657，分别。微波辐照下断裂面的分形各向异性最为明显。沿断裂面的粗糙度约为垂直断裂方向的1.02倍。从尺寸效应特征来看，微波辐照下断裂面的粗糙度与所选尺寸呈正相关。研究结果为解释微波破岩机理提供了一定的依据。