无砟轨道路基膨胀土分类分级方法试验研究

Experimental Study of the Identification and Classification of Railway Subgrade Expansive Soil

在高速铁路建设工程中对膨胀土等级的评判至关重要,如果对无砟轨道路基土壤膨胀性的判断出现失误,就会出现重大工程事故。所以,对膨胀土判别与分类方法的研究有重大意义。对体现了膨胀土胀缩机理的几个指标进行了深层次的探讨,提出了以液塑限、自由膨胀率、比表面积、蒙脱石含量和阳离子交换量等5个指标作为判定膨胀土的指标组合,给出一种新的膨胀土判别分类方法,并通过大量试验进行验证。新的判别标准精度高而且操作简便。

The identification and classification of expansive soil are very important in railway engineering,so misjudgment to expansive ballastless subgrade will lead to significant accident.Further discussions have been conducted which reflect and characterize swell-shrink mechanism and property,and 5indices are proposed as the new method to identify expansion soil such as liquid plastic limit,free swell ratio,specific surface area,montmorillonite content,cation exchange capacity.Tests have been made to verify the new method and it prove that the new identification approach is easy and reliable.