盾构触变泥浆不同体系的性能与机理研究

Study on Performance and Mechanism of Different Systems of Thixotropic Slurry for Shield Tunneling

摘要:

为满足复杂地层条件下盾构及顶管施工对支护与润滑材料性能的适配要求，以钠基膨润土为基础A液，选用水玻璃和高分子两类B液构建双液型触变泥浆体系，旨在系统探讨不同体系与配比对泥浆宏观性能与结构特征的影响规律。通过比重、黏度、静压滤失量、压缩-回弹性能及抗剪强度等指标测试，系统评估了两类材料体系的差异。结果表明：在常用配比条件下，水玻璃体系的比重、黏度及抗剪强度均高于高分子体系，体现出其较强的无机凝胶化与结构致密特征；高分子体系在滤失量与压缩–回弹性能方面表现更优，具备良好的变形恢复与保水能力。此外，随着泥水比的增加，两类体系的比重、黏度、滤失量及抗剪强度均呈上升趋势，但水玻璃体系的压缩与回弹性能略有下降，而高分子体系回弹性能显著提升，表明泥水比变化调控了颗粒间相互作用与网络结构的致密程度，也反映出无机凝胶与有机聚合物体系在应变恢复机理上的本质差异。研究揭示了双液型触变泥浆在不同体系与配比条件下的性能演化规律，为盾构及顶管施工中高性能、可调控、绿色支护与润滑材料的优化设计提供了理论依据与技术支撑。

Abstract:

To meet the performance adaptation requirements of support and lubrication materials for shield tunneling and pipe jacking under the complex ground conditions, based on sodium-based bentonite as the A liquid, two types of B liquids, namely sodium silicate and polymer, are selected to construct a two-fluid thixotropic slurry system, which aims to systematically explore the influence laws of different systems and ratios on the macroscopic properties and structural characteristics of slurry. The differences between the two material systems are systematically evaluated through tests on indicators such as specific gravity, viscosity, static pressure filtration loss, compression-resilience performance and shear strength. The results show that under the common proportioning conditions, the specific gravity, viscosity and shear strength of the sodium silicate system are all higher than those of the polymer system, demonstrating its strong inorganic gelation and dense structure characteristics. Polymer systems perform better in terms of filtration loss and compression-resilience properties, and possess the excellent deformation recovery and water retention capabilities. In addition, with the increase of slurry-water ratio, the specific gravity, viscosity, filtration loss and shear strength of the two types of systems all show an upward trend. However, the compressive and resilience properties of the sodium silicate system slightly decreases, while the resilience properties of the polymer system significantly improves, which indicates that the variation of the slurry-water ratio regulates the interaction between particles and the compactness of the network structure, and also reflects the essential differences in the strain recovery mechanism between inorganic gels and organic polymer systems. The performance evolution law of the two-fluid thixotropic slurry under different system and proportion conditions is revealed, providing a theoretical basis and technical support for the optimal design of high-performance, adjustable and environmentally friendly support and lubrication materials in shield tunneling and pipe-jacking construction.