为解决穿越膨胀岩地层的盾构隧道管片受到特殊围岩吸水膨胀变形不利影响的问题，以钠基膨润土、水泥、粉煤灰、河砂、水为原材料配制的盾构壁后注浆浆液作为基体，混掺加入聚丙烯纤维（PPF）和玄武岩纤维（BF），提高注浆结石体的缓冲能力、变形能力和韧性。通过设定不同水平的纤维体积掺量和纤维体积混掺比，探究混杂纤维对注浆浆液性能的影响规律，分析了作用机理，最后建立力学性能预测模型。研究结果表明：混杂纤维的加入对注浆浆液的性能影响显著，特别是对注浆结石体的力学性能有明显的改良增韧效果。研究结论可为混杂纤维在盾构壁后注浆工程的应用提供参考依据。

To address the issue of shield tunnel segment being adversely affected by the expansion deformation resulting from water absorption in special surrounding rock when tunneling through expansive rock stratum, a grouting slurry formulated with sodium bentonite, cement, fly ash, river sand, and water is used as the matrix for the backfill behind the shield tunnel segment. Polypropylene fiber (PPF) and basalt fiber (BF) are blended into this slurry to enhance the cushioning capacity, deformation resistance, and toughness of the grouting stone body. By setting different levels of fiber volume contents and fiber volume hybrid ratios, the influence pattern of hybrid fiber on the properties of grouting slurry was explored, and the mechanism of action was analyzed. Finally, a mechanical property prediction model was established. The research results indicate that the addition of hybrid fiber has a significant impact on the properties of the grouting slurry, particularly exhibiting notable improvement and toughening effects on the mechanical properties of the grouting stone body. The research conclusions can provide a reference for the application of hybrid fiber in the grouting project behind the shield tunnel segment.