【摘要】 基于经典塑性理论，利用失稳模量（HIN）的概念建立了非饱和土的渗流稳定性准则；针对非饱和土边坡常出现的失稳形式（即有限滑移失稳和快速流动失稳），通过引入考虑基质吸力依赖性的弹塑性本构模型，给出了识别边坡不同失稳模式的HIN表达式；对于具有潜在液化能力的松散火山灰土给出了理论模型参数的标定方式；在此基础上，预测了火山灰土边坡出现的失稳模式以及相应的失稳含水率，通过与室内水槽试验结果对比验证了理论模型的正确性和合理性，结果显示，结合无限边坡模型与失稳模量理论可进一步推导出不同失稳模式下的边坡安全系数表达式，二者互为验证；最后，通过参数分析研究了各模型参数对边坡在不同边界条件下失稳模式的影响.研究结果可进一步明晰降雨条件下非饱和土边坡出现不同失稳模式的内在机理，以便为渗流边坡稳定性的评估与设计提供相应的指导.更多还原

【Abstract】 Based on the classic plasticity theory, the criterion of seepage stability of unsaturated soil is established by the concept of instability modulus(HIN). Aiming at the post-failure mode of unsaturated soil slopes(i.e. limited frictional slips and rapid flow slides), by introducing the elastoplastic suction-dependent constitutive model, the expression of HIN identifying different failure modes of the slope is given. Taking the loose volcanic ash soil with potential liquefaction ability for example, the calibration procedure of theoretical model parameters is introduced. On this basis, the failure mode and its corresponding instability water content of volcanic ash slopes were predicted, thus validating the correctness and rationality of the theoretical model from flume tests. It is worth mentioning that based on the infinite slope model and the theory of instability modulus, the expression of the safety factor of the slope under different instability modes could be derived. Lastly, through parameter analysis, the influence of model parameters on the failure mode of the slope under different boundary conditions is investigated.This study can further clarify the inherent mechanism of different failure modes of unsaturated soil slopes under rainfall conditions, as well as provide theoretical guidance for the evaluation and design of seepage slope stability.更多还原