考虑浆液时空效应的幂律型流体盾构壁后压密注浆模型研究

Study on Back-filled Compaction Grouting Model Considering Temporal and Spatial Variation of Power-law Fluid

盾构壁后注浆已广泛应用于地下工程建设中,但是其注浆压力分布理论研究尚不能满足工程需要。为明确注浆填充压力大小及分布,基于流体力学、弹性理论相关原理及质量守恒定律,揭示了盾构壁后压密注浆机理,建立了考虑浆液时空效应的幂律型流体压密注浆模型,推导了相关计算公式,并得到以下结论:(1)浆液质点压力主要与初始注浆压力、管片半径、粘度增长时间、角增量、流变指数、盾尾间隙、粘性时变系数等参数有关;(2)通过分析计算考虑时空效应的幂律型流体压密注浆模型,得到浆液质点向上扩散时,浆液压力整体呈下降趋势;浆液质点向下扩散时,浆液压力整体上呈先上升后下降的趋势;(3)通过进一步分析浆液压力的分布变化规律,得到各注浆孔之间的最优夹角及浆液的最优扩散时间,同时与已有的研究成果相比较,可知本文的研究成果具有工程推广价值。

Shield back-filled grouting has been widely used in the construction of underground engineering, but the grouting pressure distribution theory can＇ t meet the needs of the project. In order to clarify the filled grouting pressure size and dis- tribution, based on the theory of fluid mechanics, elastic theory and the law of conservation of mass, the mechanism of post grouting of shield wall is revealed, back-filled compaction grouting model is established, and the related calculation formu- las are derived. The conclusions are as follows ： （ 1 ） Grouting particle pressure mainly relates to the initial grouting pre- ssure, segment radius, viscosity growth time, angular increment, flow behavior index, shield tail clearance, viscosity time variation coefficient. （2） Through analyzing back-filled compaction grouting model, it can be obtained that the grouting pressure decreases in general as the upward diffusion of the particle, and the grouting pressure increases first and then decreases as the downward diffusion of the particle. （3）Through further analyzing distribution and variation of grouting pressure, it can be obtained that the optimal angle between the grouting holes and the optimal diffusion time of the grouting. At the same time, corc^ring with the existed research results, the research results of this paper have engineering extension value.