盾构壁后注浆宾汉姆浆液驱替渗透扩散模型

Displacement Infiltration Diffusion Model of Binghamian Grouts as Backfill Grouting of Shield Tunnel

摘要:

以宾汉姆流型浆液为研究对象，基于浆液对地下水的驱替效应，运用广义达西定律及渗流力学相关理论，推导了壁后注浆球形驱替渗透扩散模型.通过算例分析了考虑浆液驱替效应时浆液的渗流扩散特征，并针对影响浆液渗透扩散的主要因素进行了分析.结果表明：考虑浆液驱替效应时，扩散锋面浆液压力随着扩散距离的增加沿下凹形曲线递减，虽然锋面浆液压力变化量较小，但对浆液的扩散半径影响较大，注浆1 h时浆液扩散距离减小约23%.

关键词:盾构隧道; 壁后注浆; 渗透; 驱替效应

Abstract:

With Bingham grout as the study object, this paper deduces the spherical displacement infiltration diffusion model by applying generalized Darcy's law and theories of seepage mechanics based on the displacement effect of grout for groundwater. Through examples, the characteristics of the grout infiltration diffusion when considering the grout displacement effect is analyzed, and the main factors affecting the grout infiltration diffusion is analyzed. The results show that when the grout displacement effect is considered, the grout pressure in the diffusion front decreases along the concave curve with the increase of the diffusion distance. Although the change of frontal grout pressure is small, it has a great influence on the grout diffusion radius, and the grout diffusion distance shortens about 23% at 1 h.

Key words:shield tunnel; backfill grouting; infiltration; displacement effect