New Statistical Quantification Method for the Size Effect Behavior of Rock Mass Using Compressive Strength as an Example

Abstract

The statistical law on mechanical parameters of rock mass with size is the key to the study of the size effect. Since the existing statistical methods of the size effect only consider the continuity of the size but not the difference between the samples of each size, a new statistical method that considers single size and multisize is proposed. Based on the proposed method, the true representative elementary volume (TREV) value is used to determine the size effect stability threshold. Combined with the analysis of the three major size effect theories, the unified size effect law model and variation index k are proposed. The results are validated by statistical test data on the uniaxial compressive strength (UCS) obtained in realistic failure process analysis (RFPA) numerical test and from other works, which proves that the proposed method can reflect the variation law of UCS value with size and provide a basis for theoretical research on the size effect in mechanical behavior.