牡佳铁路沿线土体膨胀性试验研究

Experimental Study on Expansibility of Soil Along Mudanjiang-Jiamusi Railway

以在建牡佳(牡丹江—佳木斯)铁路为研究对象,分析铁路沿线常见5种土质的膨胀性,从不同土质的自由膨胀率、蒙脱石含量和阳离子交换量指标间的相关性,以及自由膨胀率与土体物理指标间的相关性2方面研究膨胀指标的匹配性。结果表明:以液限、塑性指数和自由膨胀率3项指标划分牡佳铁路沿线土质膨胀性结果具有较好的一致性,而比按照蒙脱石含量和阳离子交换量划分得出的土体膨胀性低。建议在本地区的工程实践中,适当降低液限、塑性指数和自由膨胀率的等级划分标准,使这3项指标与蒙脱石含量、阳离子交换量得以相互匹配。

Taking the construction of Mudanjiang-Jiamusi railway as the research object, expansibility of 5 common soils along railway lines was analyzed, compatibility of expansion index was discussed through the correlation among free expansion rate,montmorillonite content and cation exchange capacity of different soils and correlation between free expansion rate and physical indexes of soil.The results show that soil expansibility results along Mudanjiang-Jiamusi railway obtained by 3 index division of liquid limit,plasticity index and free expansion rate have a better consistency,which is lower than that obtained by division of montmorillonite content and cation exchange capacity.It is suggested that grading division standard of liquid limit,plasticity index and free expansion rate should be reduced appropriately so that these 3 indicators can match each other with montmorillonite content and cation exchange capacity.