游离氧化铁对花岗岩残积土崩解和抗剪强度的影响

Effect of free iron oxide on disintegration and shear strength of granite residual soil

为分析游离氧化铁对花岗岩残积土的力学性质的影响,以桂东南地区花岗岩残积土为研究对象,通过连二亚硫酸钠-柠檬酸钠-碳酸氢钠(DCB法)溶液去除花岗岩残积土中的游离氧化铁,并制备了不同游离氧化铁含量的重塑土样。研究表明:游离氧化铁含量的增加显著提高了花岗岩残积土的抗剪强度,同时显著降低了其水稳定性和抗崩解性能。基于试验结果,建立了游离氧化铁含量与崩解特性及抗剪强度之间的拟合关系,有效反映了土体性质随游离氧化铁含量的变化趋势。

To analyze the effect of free iron oxide on the physical and mechanical properties of granite residual soil,the granite residual soil in southeast Guangxi was taken as the research object.The free iron oxide in granite residual soil was removed by sodium dithionite-sodium citrate-sodium bicarbonate(DCB) solution,and the remodeled soil samples with different free iron oxide contents were prepared.The results show that the shear strength of granite residual soils is significantly improved with the increase of free iron oxide content,while the water stability and anti-disintegration properties are significantly reduced.Based on the experimental results,the fitted relationship between free iron oxide content,disintegration characteristics and shear strength is established,which effectively reflects the changing trend of soil properties with free iron oxide content.