滑带泥岩蠕变加速的临界判据及弹粘塑性本构模型研究

黄河上游岩质滑坡加速蠕变启动机理复杂，滑带泥岩具有复杂变形特性和应力状态及时间效应。探明滑带泥岩蠕变加速的临界判据，对于滑坡临滑预警具有重要的科学意义和工程价值。项目针对滑带泥岩开展加速蠕变机制研究，旨在解决滑坡临滑预警技术瓶颈这一科学问题。首先，进行一系列静动荷载下三轴蠕变试验、CT和SEM试验，分析蠕变加速时应变率与偏应力、静水压力、孔压、动应力幅值的关联机制，揭示滑带泥岩蠕变加速时有效应力状态变化规律；然后，基于试验结果，研究滑带泥岩蠕变加速时有效应力状态与临界状态线的关系，揭示蠕变加速时泥岩有效应力状态与其微观结构的关联机制，确定考虑有效静水压力、偏应力及孔隙比等因素的加速蠕变临界判据；最后，基于临界状态理论和粘塑性理论，建立考虑泥岩蠕变加速的硬化法则，构建弹粘塑性本构模型，预测蠕变加速行为，并进行验证。研究成果可为泥岩滑坡临滑预警与灾害防控提供理论依据，具有重要的理论与应用价值。

The mechanism of accelerated creep of rock landslides is complex in the upstream of the Yellow River. The slip zone mudstone shows complex deformation characteristics, complex stress state, and complex time effect. Ascertaining the critical criterion for accumulated creep of slip zone mudstone has scientific significance and engineering value for critical sliding warning of landslides. The project focuses on the mechanism of accelerated creep of slip zone mudstone, and aims to solve the scientific problem on technology bottleneck in critical sliding warning of landslides. Firstly, conduct a list of triaxial creep test controlling deviatoric stress and dynamic stress amplitude, CT and SEM scan, analyze the correlation mechanism between strain rate and deviatoric stress, effective principal stress, spacing ratio, and dynamic stress amplitude, and explore the characteristics of effective stress state at initial accelerated creep of slip zone mudstone. Secondly, based on experimental results, investigate the relationship between critical state line and effective stress state at initial accelerated creep of slip zone mudstone, expound the correlation mechanism between microstructure and effective stress state at initial accelerated creep, a critical criterion for predicting accelerated creep considering effective hydrostatic pressure, deviatoric stress, and pore ratio. Finally, formulate a hardening rule that considers accelerated creep of slip zone mudstone, formulate elasto-viscoplastic constitutive model, predict accelerated creep using the constitutive model, and verify the constitutive model. The research results are expected to provide new basic theory for critical sliding warning and disaster prevention and control of mudstone landslides, and has important value for theory and application.