考虑粒组分类影响的最小孔隙比分布及模型验证

Minimum void ratio distribution and model verification considering influence of grain size fraction

最小孔隙比是确定岩土体的密实程度与孔隙特征的有效物理指标,如何快速有效地确定岩土体的最小孔隙比,可为岩土体的固结与稳定提供可靠参数。多数估算细粗混合材料最小孔隙比的模型参数与细粗粒径比一一对应,导致估算困难。在分析尾矿粒度组成、沉积规律和固结稳定的基础上,以8种不同粗细粒径,7~9种不同细粒含量尾矿为试验对象,拟合得到不同粒组尾矿最小孔隙比分布模型参数的函数关系;基于混合尾矿颗粒的粒组特征,给出了确定参数幂函数关系的指数值。分别采用模型参数要求粒组范围内的其他6组岩土材料和非粒组范围内的3组岩土材料进行验证。结果表明,考虑粒组分类影响下的模型,参数简单,对不同材料的最小孔隙比估算准确率较高,给出的最小孔隙比的分布规律合理,可为岩土工程领域最小孔隙比估算提供可靠的计算方法。

Minimum void ratio is an effective physical index to determine the compactness and pore characteristics of soil mass. A fast and effective method to determine the minimum void ratio of soil mass can provide reliable parameters for soil consolidation and stability. Most of the model parameters corresponded to the ratio of fine-coarse particle size one by one, so it is difficult to estimate the minimum void ratio of fine-coarse mixed materials. By analyzing the grain size composition, deposition and consolidation stability of tailings, and combining with the minimum void ratio test results of tailings with 8 different grain sizes and 7-9 different fine grain contents, a power function of the minimum void ratio distribution model parameters of tailings with different grain size fractions was obtained. Based on the grain size fraction of mixed tailings, the exponent values to determine the power function relationship of parameters were given. Six groups of other soil materials grain size within the range of grain size fraction and three groups grain size without the range of grain size fraction were used to verify the model parameters. The results show that the model considering the influence of grain size fraction has simple parameters and high accuracy in estimating the minimum void ratio of different soil materials. The minimum void ratio given is reasonable, and it can provide a reliable calculation method for estimating the minimum void ratio in the field of geotechnical engineering.