Abstract: The grouping of natural structural planes is critical in rock mass engineering. Traditional grouping methods are inaccurate in grouping structural planes with near-vertical or near-horizontal occurrence. In view of this, a dynamic clustering analysis method for structural planes is proposed. The clustering center is determined based on the dip angle and inclination of structural planes, and the grouping result is obtained by iterative calculation based on the angle between structural planes. The method was applied to group 303 structural planes in Bayan Obo East mine and compared with the fast clustering method. Three dominant groups of structural planes were identified after the grouping of 303 structural planes, which agree well with the isodensity map of structural plane occurrence. The dynamic clustering analysis method is not only simple and easy to calculate but also overcomes the limitations of traditional methods in quantification, making the grouping of structural planes more accurate and practically significant.

Key words: natural rock mass, structural plane, dominant occurrence, dynamic clustering