【摘要】 水-岩化学劣化是中国西北红层地区地质灾害频发的主要原因。其水-岩化学驱动机制研究，前期成果多聚焦于特定反应路径或局部化学过程（单矿物溶解、离子交换、矿物转化）,对多反应路径（水解/碳酸化/离子交换）的协同竞争机制缺乏系统解析。本研究选取中国天水-陇西地区4处典型滑坡体软弱夹层（初始矿物组成存在差异）为研究对象，利用X射线衍射仪、离子色谱仪等设备，开展15、30、45 d饱水实验，采用斯皮尔曼相关性理论分析矿物成分与离子浓度的耦合演变机制。结果表明：（1）饱水45 d后，钾长石与斜长石含量显著减少24.2%～62.3%和10.5%～28.6%,伊利石和高岭石含量显著增加4.1%～8.6%和0%～11.7%;Na⁺、Ca²⁺离子浓度分别上升18%～41%和16.5%～55%,HCO₃^-浓度增加16.8%～88%（CH除外）。（2）斯皮尔曼相关性分析揭示，红层软岩水-岩化学作用是由水解、碳酸化、离子交换等多反应动态耦合驱动的复杂过程。其中，长石类矿物减少与黏土矿物增加呈极显著负相关（相关系数分别达-0.94和-0.85）,定量证实长石经水解、碳酸化反应向伊利石、高岭石转化为主导过程；绿泥石同时存在水解与蒙脱化反应；高岭石的增减取决生成与消耗速率竞争。尽管4处试样初始矿物组成存在差异，但均呈现长石水解主导的黏土矿物转化核心路径，次要反应方向受初始组成调控。本研究首次将斯皮尔曼相关性理论引入机制分析，研究成果定量揭示矿物转化关联，可为红层软岩水化劣化全过程建模与风险预警奠定理论基础。更多还原

【Abstract】 Geotechinal degradation due to hydro-chemo coupling is primary trigger for massive geohazards in red-bed regions of Northwestern China. Previous research on the chemical driving mechanisms of water-rock interactions paid most attentions to individual reaction pathways（e.g., mineral dissolution, ion exchange, mineral transformation）, lacking systematic analysis of synergistic/competitive coupling among multiple reaction pathways（hydrolysis/carbonation/ion exchange）.In this study, four typical weak interlayers with distinct initial mineral compositions from representative landslide bodies were investigated in the Tianshui-Longxi areas. Through 15/30/45-day specimen preparation of saturation, it used X-ray diffractometer（XRD）, ion chromatography（IC）, and other instruments, with Spearman correlation theory to decipher the coupled evolution of mineral phases and ion concentrations. It has the following key findings.（1） After 45-day of saturation, potash feldspar and plagioclase contents decreased by 24.2%-62.3% and 10.5%-28.6%, respectively, whereas illite and kaolinite contents increased by 4.1%-8.6% and 0-11.7 %, respectively. Na⁺ and Ca²⁺ concentrations rose by 18%-41% and 16.5%-55%, respectively, and HCO₃^- increased by 16.8-88 %（except for CH）.（2） Spearman correlation analysis revealed that the hydro-chemical interaction in red-bed soft rock were complex processes, dynamically driven by the coupling of hydrolysis, carbonation and ion exchange. Among them, a significant negative correlations between feldspar decrease and clay-mineral increase（the correlation coefficients are-0.94 and-0.85 respectively） quantitatively confirm that feldspar transformation into illite and kaolinite via hydrolysis and carbonation dominated the process. Chlorite underwent simultaneous hydrolysis and montmorillonitization, whereas kaolinite abundance was governed by the competition between rates in generation and consumption. Despite the four specimen differed in initial mineralogy, all exhibited feldspar hydrolysis-controlled clay-mineral transformation as the core pathway, with secondary reactions modulated by initial composition.This study is the first to introduce Spearman correlation theory into mechanism analysis of red-bed soft rock failure, offering a quantitative basis for modelling the full hydration degradation process and early-warning of associated hazards.更多还原