水-气耦合下的土质边坡稳定系数场分析

传统边坡稳定性分析方法仅对潜在滑动面进行整体稳定性评估，无法获取各点的安全系数，为了准确分析边坡稳定性，基于稳定系数场理论，综合考虑水-气耦合作用对降雨条件下边坡稳定性进行分析。结果表明：1）稳定系数场法能够直观地体现水-气耦合作用下边坡的具体破坏区域，得到各点的安全系数；2）孔隙气压力对边坡降雨入渗有一定阻碍作用，并且随降雨时间的推移阻渗效果愈明显，相同条件下降雨40 h时，两相流湿润锋深度较单向流减小了28.6%；3）相同条件下，考虑水-气耦合作用会降低边坡稳定性，以降雨40 h为例，两相流边坡失稳面积约为单向流的1.7倍。因此，在实际工程中对边坡稳定性分析时应考虑水-气耦合作用，工程偏于安全。

Analysis of local safety factor of soil slope considering water-air coupling

The traditional slope stability analysis method only evaluates the overall stability of the potential sliding surface, and cannot obtain the safety factor of each point. In order to accurately analyze the stability of the slope, based on the theory of local safety factor, the stability of the slope under rainfall conditions is analyzed comprehensively considering the water-air coupling effect. The results show that: 1) The method of local safety factor can directly reflect the specific failure area of the slope under the water-air coupling; 2) The pore gas pressure has a little anti-infiltration effect on the slope rainfall infiltration, and the anti-infiltration effect becomes more obvious with the passage of rainfall time. Under the same conditions, when the rainfall is 40 hours, the depth of the wet front of the two-phase flow is reduced by 28.6% compared with the unidirectional flow; 3) Considering that the effect of water-air coupling will reduce the stability of slope, when the rainfall is 40 hours, the instability area of the two-phase flow slope is about 1.7 times that of the unidirectional flow under the same conditions. Therefore, the water-air coupling effect should be considered when analyzing the slope stability in actual engineering, and the engineering tends to be safer.