冻融循环对黑土容重和孔隙度影响的试验研究

反复的冻融循环会通过改变土壤容重、孔隙度等物理性质而使其侵蚀加剧,该文探讨了土壤容重及孔隙度在冻融循环作用下的变化.试从机理上分析冻融作用对土壤抗蚀性的影响规律.以东北黑土为研究对象,考虑冻融温差和土壤含水率两个影响因素.通过室内冻融试验研究了黑土容重及孔隙度的变化规律.结果表明:随着冻融循环次数的增大,土壤的容重和孔隙度分别呈现缓慢减小及增大趋势,且变化幅度越来越小,最后达到基本稳定的状态;冻融温差越大,冻结温度越低,同一含水率土壤的容重变得更低,而孔隙度相对较高,并且两者的变化量最大;在同一冻融温差下,高含水率土壤经过冻融循环后较低含水率土壤容重更低,而孔隙度更高,且数值的变化量最大.

Study on Effects of Freeze-Thaw Cycle on Bulk Density and Porosity of Black Soil

Repeated freeze-thaw cycles cause changes in soil bulk density and property,making the erosion seriously,discusses the variation of soil bulk density and porosity under the action of the freeze-thaw cycle,try to analvze the freeze-thaw effects on soil anti-erodibility from mechanism.Black soil of northeast China as the research object,consider freezing temperature and soil moisture,through the indoor freeze-thaw test study of bulk density and porosity of the black soil.The results showed that:With the increasing of freeze-thaw cycles,soil bulk density and porosity were presented slowly increase or decrease and in the trend of getting change smaller and smaller range,finally achieved basically stable state;the greater the temperature difference between freezing and thawing,the lower the freezing temperature,soil bulk density become smaller and the porosity is relatively large in the same moisture content,and both the largest amount of change;in the same freeze-thaw temperature difference.the high moisture content of soil after freeze-thaw cycles compared to a low moisture content of soil bulk density lower,while the higher porosity,and the largest numerical changes.