考虑缩尺效应对堆石料颗粒破碎影响的压缩试验研究

Compression Experimental Study on the Influence of Scale Effect on Particle Breakage of Rockfill

大量的压缩试验结果表明,堆石料试样的压缩特性和颗粒破碎特性存在明显的缩尺效应,但系统研究缩尺方法、试样最大粒径、试样直径等对颗粒破碎特性的影响较少。采用侧限压缩试验开展灰岩堆石料的尺寸效应研究,分析了缩尺方法、试样直径和试样最大粒径对压缩特性和颗粒破碎特性的影响规律。结果表明:压缩系数随着试样中粗颗粒含量的上升呈先降低后增大的趋势,压缩系数与试样最大粒径呈正相关,与试样直径呈负相关;引入相对颗粒破碎率评价指标,建立了缩尺方法与相对颗粒破碎率之间的幂函数关系,相对颗粒破碎率随试样直径和试样最大粒径的发展规律可拟合为曲面方程。研究成果可为进一步构建考虑缩尺效应的弹塑性本构模型提供理论基础。

A comprehensive investigation into the compression characteristics and particle crushing behavior of rockfill samples has revealed a significant scale effect,while the study on influences of scale method,maximum particle size,and sample dimensions have been found to be relatively less significant.To begin with,confined compression tests and screening tests were conducted to study the size effect of limestone rockfill.The study examined the variations of compression coefficient and particle crushing behavior with respect to the scale method,sample dimensions,and maximum particle size.Results indicate that compression coefficient initially decreases and then increases with the increase in coarse particle content within the sample.Moreover,a positive correlation was observed between the compression coefficient and the maximum particle size of the sample,while a negative correlation was found between compression coefficient and sample size.To assess the degree of particle breakage,a relative particle crushing rate was employed to establish a power function relationship between the scale method and the relative particle crushing rate.The patterns of particle crushing rate development in relation to sample size and maximum particle size can be fitted into a curved surface equation.The findings of this research contribute to the establishment of a constitutive model that accounts for the scale effect.