黄土物理性质变化规律研究

研究了黄土孔隙度和湿陷性在垂向上变化的规律和原因 .结果表明 ,孔隙度高和湿陷强的层位是风化成壤弱的黄土层 ,孔隙度低和湿陷弱的层位是红色古土壤或风化成壤强的黄土层 .第四纪冷干与温湿气候的交替和由此产生的成壤过程的变化是造成黄土地层孔隙度和湿陷性波动变化的根本原因 .黄土湿陷性是在干旱与半干旱地区弱的成壤过程中产生的 ,是草原地带灰黄色土壤具有的特征 .

Research on change law of loessial physical property

The loessial porosity and collapsibility change undulationally in the vertical direction.The loessial layers which have high porosity and strong collapsibility underwent the weak weathering and soil formation processes.The loessial layer which have the low porosity and weak collapsibility are the red fossil soils or the loessial layers weathered strongly.The replacement of the cold arid and the warm moist climate in Quaternary period caused the change of the soil formation processes, which is the primary cause that makes the porosity and collapsibility of the loessial layers change undulationally. The loessial collapsibility came into being in the weak soil forming processes of the arid and semiearid area, it is the characteristic of several kinds of grey and yellow soils in steppe area.