青藏高原构造混杂岩带的孕灾地质基因与重大工程地质问题研究

孕灾地质基因是指一定区域所具有的促进地质灾害孕生的内在关键因素。板块构造混杂岩带所处的特殊构造部位决定了其复杂的演化过程和特殊的地质基因。本文在梳理青藏高原构造混杂岩带地质特征的基础上，总结分析了其孕灾地质基因，包括活跃的地质构造、复杂的水热条件、混杂的岩性组合、特殊的蚀变软岩和构造岩溶导水通道等，是引发重大地质灾害和工程地质安全风险的根源。结合典型案例，剖析了构造混杂岩带大型滑坡的成因类型主要有三大类：构造控制型、泥质软岩控制型和蚀变蛇绿岩带控制型，其中蚀变蛇绿岩带是构造混杂岩带最具特色的易滑地质结构，具有典型的地质构造与特殊岩性联合控制特征。构造混杂岩带隧道工程变形破坏主要有塌方、水平收敛、环向收敛、底鼓和错断等五种模式，黏土化蚀变软岩的不良工程特性是制约构造混杂岩带隧道围岩稳定性的重要因素。针对传统的工程地质理论和灾害风险防控技术难以适应构造混杂岩带大规模工程建设面临的挑战，提出了有待深入研究的关键问题和防灾减灾策略。

Research on hazard prone geological genes and major engineering geological problems in tectonic meange belts of Tibetan Plateau

The hazard prone geological genes refer to the internal key factors that promote the conception of geohazards in a certain region. The special tectonic position of the plate tectonic mélange belt determines its complex geological evolution process and distinct geological characteristics, making it a critical zone for major engineering geological problems and frequent geological disasters. By examining the main geological characteristics of the tectonic mélange belts on the Tibetan Plateau, this paper summarizes and analyzes the special geological factors associated with geohazards. These factors include active geological structures, complex hydrothermal conditions, mixed lithologies, special altered soft rocks, and tectonic karst water channels, all of which serve as key contributors to major geohazards and engineering geological risks. Combined with typical cases, the causes of large scale landslides in tectonic mélange belts are analyzed, primarily divided into three types: tectonic control type, argillaceous soft rock control type, and altered ophiolite belt control type. Among them, the altered ophiolite belt exhibits the most distinctive prone to slide geological structure within the tectonic mélange belt, characterized by a combination of specific lithology and geological structures. Tunnel engineering within tectonic mélange belts experiences five main deformation and failure modes, including collapse, horizontal convergence, circular convergence, floor lift, and dislocation. The unfavorable engineering characteristics of clayey altered soft rock are an important factor restricting the stability of tunnel surrounding rock within the tectonic mélange belt. In view of traditional engineering geological theory and risk prevention and control technology, this study identifies key research areas and proposes disaster prevention and mitigation strategies to address the challenges faced by large scale engineering construction in the tectonic mélange belt.