湿-热交互作用下炭质泥岩边坡灾变机理与减灾方法研究

The strength of carbonaceous mudstone is rapidly deteriorated with the development of fracture under thermo-hydro interaction, which may easily result in the large-scale continuous progressive unstable failure of carbonaceous mudstone slope. Due to the research on damage evolution and catastrophic mechanism of carbonaceous mudstone under thermo-hydro interaction are not yet deep, the theory of stability calculation which can consider the progressive damage and its effective control methods have not been widely reported. It leads to damage process of the carbonaceous mudstone slope from outside to inside is still can’t be effective mitigation and control. In view of the above reasons, this project will carry out the research of disintegration mechanism and fracture evolution law of carbonaceous mudstone based on physical, chemistry and three-dimensional CT reconstruction method. The environmental variable controllable experiment equipment will be developed and the macro-meso mechanical characteristics under thermo-hydro interaction will be studied. The damage constitutive will also be set up. The equivalent indirect method of Mohr-Coulomb strength considering the characteristics of progressive damage basing on the Hoek-Brown criterion will be conducted. Also, the carbonaceous mudstone slope stability calculation theory which can consider the progressive damage under thermo-hydro interaction will be established. A targeted stability control method will be proposed by analyzing catastrophe mechanism of carbonaceous mudstone slope under the influence of single and multiple factors. The research results are of great significance to improve the soft rock slope catastrophe prevention and reduction theory in China.

炭质泥岩在湿热交互作用下强度随裂隙形成发育而迅速劣化，极易导致炭质泥岩边坡发生持续渐进式大规模失稳破坏。由于湿热交互作用下炭质泥岩边坡的灾变机理研究尚不深入，因此能考虑渐进损伤的稳定性计算理论及针对性控制方法的研究成果仍少见报导，导致炭质泥岩边坡由表及里的渐进损伤过程仍未得到有效减缓及控制。鉴于以上原因，本项目拟开展基于物理化学及三维CT重建方法的炭质泥岩裂隙形成机制及演化规律研究；研发环境变量可控的试验装置，开展湿热交互作用下炭质泥岩宏细观力学特征研究，构建炭质泥岩损伤本构模型；基于Hoek-Brown准则，推导能考虑渐进损伤特征的Mohr-Coulomb强度等效间接解法，得到湿-热交互作用下能考虑渐进损伤的炭质泥岩边坡稳定性计算方法；通过揭示单、多因素影响下的炭质泥岩边坡灾变机制，提出湿热交互作用下针对性的炭质泥岩边坡稳定性控制方法。研究成果对完善我国软岩边坡防灾减灾理论具重要意义。

炭质泥岩在湿热交互作用下强度随裂隙形成发育而迅速劣化，极易导致炭质泥岩边坡发生持续渐进式大规模失稳破坏。目前关于炭质泥岩边坡由表及里的渐进损伤过程的研究尚不深入，暂无有效减缓及控制炭质泥岩边坡浅层失稳的有效方法。为此，项目组成员采用室内试验、理论分析及数值模拟等手段，分析在湿-热交互作用下炭质泥岩的抗剪强度特性和变形特性，并结合CT损伤变量参数分析炭质泥岩强度与内部孔隙变化的关系；基于Hoek-Brown准则，推导能考虑渐进损伤特征的Mohr-Coulomb强度等效间接解法，得到湿-热交互作用下能考虑渐进损伤的炭质泥岩边坡稳定性计算方法；对炭质泥岩崩解机理、暂态饱和区扩展演化机制及边坡失稳模式展开研究，提出了“表层抑制裂隙产生-内部控制水分迁移-底层防止裂隙拓展”的“逐层递进防控”的处治思路，建立了“表层阻隔、中层堵排、底层加固”的炭质泥岩边坡浅层灾变处治技术。