粒径对膨胀土无荷膨胀率的影响研究

为了研究粒径大小对重塑土无荷膨胀率试验结果的影响,在符合现有规范的试验条件下,将某地基泥岩碾碎成1~2 mm、0.1~1 mm、0.1 mm的三种不同粒径,进行不同比例组合搭配的重塑土无荷膨胀率试验。试验结果表明:不同粒径大小的膨胀土样的无荷膨胀率试验结果有很大差异,并且不同粒径组合下的无荷膨胀率试验结果呈正态分布趋势,且峰值处的无荷膨胀率值为该重塑土稳定、可靠的无荷膨胀率值,无荷膨胀率试验结果接近峰值处无荷膨胀率值的粒径级配为该重塑土的最佳级配。经过分析得到使重塑土无荷膨胀率结果稳定、可靠的粒径级配是1~2 mm、0.1~1 mm、0.1 mm的土粒质量比为0∶100∶0,即使重塑土无荷膨胀率试验结果稳定可靠的粒径范围为0.1~1 mm。在该粒径范围内的重塑土无荷膨胀率试验结果最为真实、准确。

Study on effect from particle size on load-free swelling rate of expansive soil

In order to study the effect from particle size on the experimental result of the load-free swelling rate of remolded soil， an experiment on the load-free swelling rate of remolded soil with the combinations of different proportions is carried out by crushing the mudstone from a foundation into three different particle sizes，i. e. ，1 ～ 2 mm，0. 1 ～ 1 mm and ＜ 0. 1 mm，under the experiment condition that complies with the relevant specifications. The experiment result shows that larger differences are there among the experiment results of the load-free swelling rates of the expansive soil samples with different particle sizes，furthermore， the experiment results of the load-free swelling rates under different particle size combinations present the normal distribution trends，while the value of the load-free swelling rate at the peak value is the stable and reliable load-free swelling rate for the remolded soil，and then the particle size gradation with the experiment result of the load-free swelling rate approaching the value of the load-free swelling rate at the peak value is the best gradation. Through the relevant analysis，it is obtained that the particle size gradations which can make the experiment results of the load-free swelling rates of the remolded soil stable and reliable are 1 ～ 2 mm，0. 1 ～ 1 mm and ＜ 0. 1 mm with the mass ratio of 0 ∶ 100 ∶ 0，thus the particle size range that can make the experiment result of the load-free swelling rate of the remolded soil stable and reliable is 0. 1 ～ 1 mm. Only within this particle size range， the experiment result of the load-free swelling rate of the remolded soil can be most real and correct.