【摘要】 目前对钙质土压缩特性的研究主要集中在钙质细砂，而实际工程中广泛存在钙质粗粒料，因此对钙质粗粒料压缩特性开展研究具有重要意义。通过颗粒强度测定仪和全自动大型固结仪对钙质土进行了单颗粒破碎试验和一维压缩试验，研究了颗粒粒径和相对密度对钙质粗粒料的颗粒强度和压缩特性的影响。单颗粒试验结果表明，钙质砂单颗粒的特征应力随着颗粒相对密度的增大而增大；单颗粒的破碎强度具有明显的尺寸效应，可利用单颗粒的特征应力进行标准化，且服从Weibull分布。压缩试验结果表明，单一粒径试样破碎后的分形维数随颗粒粒径的增大而增大；试样的Hardin破碎率与塑性功的关系为幂函数关系；在本次试验条件下，单一粒径试样的屈服应力与单颗粒的特征应力存在近似线性关系。更多还原

【Abstract】 At present, many studies have been done on the compression properties of calcareous fine sand. However, there is also calcareous coarse sand extensively existing in practical engineering. Therefore, it is important to investigate the compression characteristics of calcareous coarse sand. In present study, single particle crushing tests and one-dimensional oedometer tests of calcareous coarse sand with a single particle size were carried out using particle strength tester and automatic large-scale consolidation instrument. The effects of particle size and specific gravity on single particle strength and compression properties of calcareous coarse sand were studied. The single particle crushing test results show that the characteristic stress of single particles increases with the increment of specific gravity. The single particle strength, which can be normalized by the characteristic stress of single particles, is effected by particle size greatly. A curve for survival probability of single particle can be created based on a Weibull distribution. The oedometer test results show that the fractal dimension used to describe the gradation of sand after tests increases with the increase of the particle size; and the relationship between the Hardin’s crushing index and the plastic work is a power function. There is an approximate linear relationship between the yield stress of calcareous coarse sand with a single particle size and the characteristic stress of single particles.更多还原