中文摘要：

通过试验得到了土层中有竖向节理裂隙和无竖向节理裂隙2种黄土物理力学参数随含水率变化的规律。利用硐室围岩应力的表达式和莫尔一库伦强度准则给出了黄土窑洞安全系数的定义，分析得到重现期为10年，即有效降雨量为277mm时的降雨入渗深度为286cm，计算得到了窑洞安全系数最小值为1．183。当废弃窑洞覆盖土层中含有竖向节理，雨水可以直接到达窑洞周围土体，使含水率增大，力学参数降低，计算得到窑洞安全系数最大值为0．657。同时依据毕肖普条分法得到了分层边坡的计算公式，稳定安全系数最小值为5．537。结果表明：降雨量为277mm时，无竖向节理裂隙的窑洞稳定，有竖向节理裂隙的窑洞破坏，边坡均处于稳定状态。

英文摘要：

The law of two kinds of loess physical and mechanical parameters changing with moisture content whether loess with or without vertical joint fissure was obtained through experimental analysis. Safety factor was defined by surrounding rock stress expression and Mohr- Coulomb strength criterion. Rainfall Infiltration depth was 286 cm and the minimum value of safety factor was 1. 183 while effective rainfall was 277 mm that return period was 10 years. Rain could directly reach the cave surrounding soil that the mechanical parameters reduced with moisture content increasing and maximum value of safety factor was 1. 183 when abandoned cave overlying soil had vertical joints. Meanwhile, stratified slope calculation formulae were obtained by Bishop slice method that the minimum value of stability safety factor was 5. 537. Results show that when rainfall is 277 mm, loess cave dwelling is stable without vertical joint fissure and is damaged with vertical ioints, and the slope is in the steadv state.