为了研究孔隙气压力和负孔隙水压力在土坡稳定分析中所起的作用,基于多相流理论建立水-气二相流模型,利用此模型对稳定渗流情况和降雨情况下的土体边坡内水相和气相的渗流状态进行模拟,根据模拟得到的孔隙气压力和孔隙水压力值求出土坡安全系数.计算结果表明,土坡非饱和区负孔隙水压力的存在较大地提高了土坡稳定性,在稳定渗流情况下,孔隙气压力对土坡稳定的影响可忽略,在降雨情况下,非饱和区产生的孔隙气压力使得安全系数减小,滑动面与地下水位的距离越大,非饱和区的孔压对土坡稳定的影响越大.%Based on the multi-phase flow theory, a water-air two-phase flow model is established to study the effects of the pore air pressure and negative pore water pressure in the soil slope stability analysis. Using the model, the water flow and air flow in soil slope under steady seepage and rainfall conditions are simulated, and safety coefficients of the soil slope are calculated. Hie results show that the soil slope stability can evidently increase under the effect of the negative pore water pressure of the unsaturated zone. Hie pore air pressure in the unsaturated zone can be neglected under steady seepage condition, which should be taken into consideration under rainfall condition as it can reduce the safety coefficient. Influence of the pore pressure of unsaturated zone on soil slope stability will increase with the distance between the slip surface and the underground water level.
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