弱酸溶蚀原状黄土结构损伤机制及强度劣化效应

随着黄土地区工业化及城市化进程推进，工业废水、煤矿废水、城市污水等弱酸性水入渗溶蚀黄土边坡日益增多。黏土矿物-碳酸盐胶结作用作为形成黄土结构骨架的重要条件，是维持黄土结构强度基础来源。然而，碳酸盐胶结物易在弱酸性水作用下发生化学溶蚀流失，引起黄土结构损伤及强度劣化，进而诱发有别于中性水入渗的特殊黄土地质灾害。项目聚焦这一基础科学问题，拟开展弱酸溶蚀原状黄土结构损伤机制及强度劣化效应研究，包括：（1）弱酸溶蚀原状黄土离子迁移及矿物成分变化；（2）弱酸溶蚀原状黄土微-细观结构损伤演化机制；（3）弱酸溶蚀原状黄土强度劣化效应及理论模型；（4）弱酸溶蚀黄土边坡孕灾机制及灾变失稳判据，系统分析弱酸溶蚀原状黄土微-细-宏观结构损伤及强度劣化规律，进而揭示弱酸性水入渗黄土边坡孕灾机制。研究可为弱酸溶蚀黄土的结构损伤机制及强度劣化效应评价提供科学依据，同时可为弱酸入渗黄土边坡孕灾机制揭示提供基础参考。

With the development of industrialization and urbanization in loess area, weak acid water, such as industrial waste water, coal mine waste water and urban waste water, infiltrates and erodes loess slope more and more. The clay mineral-carbonate cementation of loess is an important source of structural framework and strength formation of loess. However, the carbonate cementation is prone to chemical dissolution under the action of weak acid, which leads to the deterioration of its mechanical properties, and then induces a special loess disaster different from the neutral water infiltration. Focusing on this basic scientific issue, the project plans to study on structural damage mechanism and strength degradation effect of undisturbed loess by weak acid dissolution, including: (1) The ion migration and mineral composition change of undisturbed loess by weak acid dissolution; (2) The damage evolution mechanism of micro-meso structure of undisturbed loess by weak acid dissolution; (3) The strength degradation effect and theoretical model of undisturbed loess by weak acid dissolution; (4) The disaster mechanism and the instability criterion of the weak acid eroded loess slope. The micro-meso-macro structure damage rule and strength degradation rule of undisturbed loess by weak acid dissolution are analyzed systematically, and then the disaster mechanism and instability criterion of weak acid water infiltrated loess slope are revealed. The study can provide a scientific basis for the evaluation of structural damage mechanism and strength degradation effect of loess caused by weak acid infiltration, and can also provide a reference for the cognition of the disaster mechanism of weak acid eroded loess slope.