Statistical Analysis on Size Effect of Splitting Tensile Strength of Mixed Buffer Backfill Materials
The mixed buffer backfill materials in the high-level radioactive waste deep geological repository is a multi-phase composite material compacted by bentonite and various admixtures.In the process of multi-component mixing and pressing,the internal defects such as holes and microcracks are randomly distributed,and its tensile strength value shows great variability even under the same test conditions.In order to clarify the influence of the thickness-to-diameter ratio of the test sample on the splitting tensile strength of the mixed buffer backfill materials,a large number of Brazilian splitting tests were carried out on specimens with different thickness-to-diameter ratios,and the statistical characteristics and distribution of tensile strength of specimens with different thickness-to-diameter ratios were discussed.The results show as follows.There is a significant power function relationship between the splitting tensile strength and thickness-diameter ratio of the disc,and the significance test result is less than 0.05.The mean value,range,standard deviation and coefficient of variation of splitting tensile strength of mixed buffer backfill materials show obvious size effect.When the disc thickness-to-diameter ratio is 1.0,the range,standard deviation and coefficient of variation of splitting tensile strength are the smallest.From the statistical characteristics,it is recommended that the disc thickness-to-diameter ratio be set as 1.0 when Brazil splitting test is conducted.According to K-S test and finite comparison method,the optimal distribution probability of splitting tensile strength is different with the thickness-to-diameter ratio of the disc.The normal distribution and Weibull distribution of the four probability distributions forms can better describe the splitting tensile strength distribution of mixed buffer backfill materials.
万方数据
维普
