库水作用下千枚岩深层倾倒变形体失稳软化机制研究

Deep-seated toppling deformation is a common slope deformation phenomenon in deep canyons on the eastern side of Qinghai-Tibet plateau. With the gradual completion and operation of many large-scale hydropower projects, the instability of large-scale deep-seated toppling deformation bodies distributed centrally has become increasingly highlighted. In this project, a systematic study will be conducted on the softening effect of flexural zone under long-term immersion in reservoir water, which is a key link in the evaluation of deformation stability. The degree of bending damage of rock mass in flexural zone will be studied by means of macroscopic and microscopic comprehensive methods. Meanwhile, the deterioration of microstructure, physical-mechanical properties of rock mass in flexural zone under long-term immersion condition will be revealed. Finally, the mechanism of progressive instability of typical phyllite toppling deformation will be explored under the action of reservoir water. On the basis of these studies, it is expected to provide parameter support for the stability evolution analysis of the deep-seated toppling deformation body of phyllite rockmass on the bank of the reservoir, thus provides the theoretical basis for the bank landslide risk prevention and control.

深层倾倒变形是青藏高原东侧深切峡谷地区普遍发育的斜坡变形现象,随着诸多大型水电工程的逐步建成和运营，集中分布的大规模深层倾倒变形体在库水作用下失稳问题逐渐突显。本课题针对弯折带在库水长期浸泡下的软化效应这一评估变形体稳定性的关键环节进行系统研究，在采用宏、微观综合手段对弯折带岩体损伤程度判识研究基础上，揭示弯折带岩体长期浸泡条件下的微观结构、物理力学特性劣化规律，探索库水作用下千枚岩质典型软岩深层倾倒变形体的渐进失稳机制，以期为库岸千枚岩深层倾倒变形体的稳定性演化分析提供参数支撑，从而为库岸滑坡风险防控提供理论依据。

深层倾倒变形是青藏高原东侧深切峡谷地区普遍发育的斜坡变形现象，随着诸多大型水电工程的逐步建成和运营，集中分布的大规模深层倾倒变形体在库水作用下失稳问题逐渐突显。本课题针对深层倾倒变形体不同倾倒程度岩体的损伤和岩体在库水长期浸泡下的软化效应这一评估变形体稳定性的关键环节进行了系统研究。在采用宏、微观综合手段对不同倾倒程度岩体损伤程度判识研究基础上，揭示了不同倾倒损伤程度的岩体长期浸泡条件下的微观结构、物理力学特性劣化规律；基于典型千枚岩深层倾倒变形体随浸泡时间进行动态赋参，对不同浸泡时间下的变形体斜坡的稳定性和变形特征进行评价，获得变形体随浸泡时间的稳定性动态演化过程。本项目研究成果可为库岸千枚岩深层倾倒变形体的稳定性演化分析提供支撑，从而为库岸滑坡风险防控提供理论依据。