陕北黄土边坡瞬态安全系数的研究

Transient safety factor research of loess slope in the northern Shaanxi Province

以陕北府谷县黄土边坡为研究对象,采用常规直剪试验和常规三轴不固结不排水试验,研究了陕北Q3黄土抗剪强度随含水量变化的规律,并提出黄土随含水量变化的抗剪强度公式;运用非饱和土壤水分运动理论,建立了以体积含水率为因变量的降雨入渗模型,并求出其数值解,根据陕北地区的降雨特点,设定不同的降雨类型,分析了不同的降雨条件下Q3黄土边坡瞬态体积含水率分布规律;在此基础上建立考虑降雨入渗影响的Q3黄土边坡瞬态安全系数的计算公式并编制了计算程序,分析不同降雨条件对陕北黄土边坡稳定性的影响。

Based on studying the loess slope in the Fugu county of the northern Shaanxi Province, through the conventional direct - shear test and the triaxial test, this paper deduces the formula of the shear strength of loess with different water content after studying the regulation relationship between shear strength and water content of Q3 loess. The model can simulate the moisture variety in loess in different rainfall condition. Based on the rain characteristic of loess in the northern Shaanxi Province, the paper analyzes the transient water content changes of Q3 loess slope in the different rainfall. A model considering the effects of the rain infiltration on transient safety in the unsaturated loess slope is proposed. Then a computer program is compiled ; The slope stability influenced by the rain filtration is discussed in detail.