摘要
高放废物深地质处置库中的混合型缓冲回填材料是由膨润土和各类掺合料压实而成的多相复合材料,在多组分混合与压制过程中其内部孔洞、微裂隙等缺陷随机分布,即使在相同试验条件下其抗拉强度值也表现出较大的变异性。为阐明试验试样厚径比对混合型缓冲回填材料劈裂抗拉强度的影响规律,针对不同厚径比试样开展了大量的巴西劈裂试验,探讨了不同厚径比试样抗拉强度统计特征及分布概型。结果表明:混合型缓冲回填材料试样劈裂抗拉强度与圆盘厚径比呈显著的幂函数关系,显著性检验结果小于0.05。混合型缓冲回填材料劈裂抗拉强度的均值、极差、标准差及变异系数都呈现出明显的尺寸效应。圆盘厚径比为1.0时,劈裂抗拉强度的极差、标准差及变异系数均最小,从统计特征来看,建议进行巴西劈裂试验时圆盘厚径比设定为1.0。根据K-S检验和有限比较法知圆盘厚径比不同,劈裂抗拉强度最优分布概型也不相同。常用的4种概率分布形式中的正态分布和威布尔分布能更好地描述混合型缓冲回填材料劈裂抗拉强度分布规律。
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.
作者
陈鑫
余文亮
CHEN Xin;YU Wen-liang(State Key Laboratory of Nuclear Resources and Environment,East China University of Technology,Nanchang 330013,China;School of Civil and Architectural Engineering,East China University of Technology,Nanchang 330013,China)
出处
《科学技术与工程》
北大核心
2024年第10期4229-4238,共10页
Science Technology and Engineering
基金
核资源与环境国家重点实验室开放基金(2020NRE21)
国家自然科学基金(42061011,41672278)。
关键词
缓冲回填材料
巴西劈裂
抗拉强度
厚径比
正态分布
威布尔分布
buffer backfill material
Brazil split
tensile strength
thickness-to-diameter ratio
normal distribution
weibull distribution
