游离氧化铁对崩岗不同土层土壤胀缩特性的影响

Effect of free iron oxide on swelling-shrinkage characteristics of collapsing hill soils in different layers

【目的】研究游离氧化铁对崩岗不同土层土壤胀缩特性的影响。【方法】利用无荷膨胀试验、线性收缩试验和计算土壤胶体扩散双电层中滑动层厚度,分析游离氧化铁对崩岗不同土层土壤胀缩特性的影响。【结果】游离氧化铁含量与崩岗土壤无荷膨胀率呈线性递增关系(P<0.01),与土壤线性收缩率呈线性递减关系(P<0.05);在电解质浓度相同的条件下,崩岗土壤滑动层厚度随着游离氧化铁含量的提高而增大;游离氧化铁含量不同的红土层、砂土层的土壤滑动层厚度与无荷膨胀率均呈显著正相关(P<0.05),与线性收缩率呈显著负相关(P<0.05)。【结论】游离氧化铁含量影响土壤滑动层厚度,进而影响土壤的胀缩性能。

【Objective】The study aimed to investigate the effect of free iron oxide on the soil swelling and shrinkage characteristics of different soil layers in the collapsing hill.【Method】Analyze the influence of free iron oxide on the soil swelling and shrinkage characteristics of different soil layers in the collapsing hill by using the no-load expansion test,linear shrinkage test,and calculation of the sliding layer thickness in the soil colloid diffusion double layer.【Result】The content of free iron oxide have a great significant linear increasing relationship with the no-load expansion rate of the collapse wall soil(P<0.01),and a significant linear decreasing relationship with the linear shrinkage rate of the soil(P<0.05);In the same electrolyte concentration,the thickness of the sliding layer of the collapsed soil showed an increasing trend with the increase of free iron oxide;there was a significant positive correlation(P<0.05)between the thickness of soil sliding layer and the no-load expansion rate of red soil and sandy soil with different free iron oxide content(P<0.05),and a significant negative correlation(P<0.05)with the final shrinkage rate.【Conclusion】The change of free iron oxide content can affect the thickness of soil sliding layer and then affect the expansion and shrinkage properties of soil.