Groutability of cement-based grout with consideration of viscosity and filtration phenomenon
Groutability of cement-based grout with consideration of viscosity and filtration phenomenon
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DOI：
10.1002/nag.785
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发表时间：
2009-11-01
影响因子：
4
通讯作者：
Choi, Hangseok
中科院分区：
文献类型：
--
作者：
Kim, Jong-Sun;Lee, In-Mo;Choi, Hangseok
可灌性取决于灌浆的性质、注浆过程和土层的力学性质。在向多孔介质注浆的过程中，浆液的粘度随时间发生变化。此外，颗粒过滤现象将限制灌浆区的扩展，因为水泥颗粒在土基中逐渐停滞。通过应用质量平衡方程和广义唯象渗流定律，推导出了水泥基浆液在土体中沉积的封闭解。通过逐步数值计算，考虑了化学反应引起的粘度变化和土孔中浆液颗粒沉积引起的孔隙率降低，对与特定球形流动相关的闭合解进行了修正。通过一系列中试室内注浆试验，验证了所开发的逐步数值计算方法能够评价注浆的可注入量和浆液颗粒的沉积情况。燃烧室喷射试验结果与分步数值计算结果吻合较好。基于渗流现象，还提出了一种可行的评价多孔介质中水泥基灌浆可灌性的方法，有助于对灌浆工艺的设计有一个新的认识。版权所有(C)2009 John Wiley&Sons，Ltd.
The groutability depends on the properties of the grout, its injection processes, and on the mechanical properties of the soil formation. During the process of pouring cement-based grouting into a porous medium, a variation with time occurs in the viscosity of grout suspension. In addition, the particle filtration phenomenon will limit the expansion of the grouted zone because cement particles are progressively stagnant within the soil matrix. In this paper, a closed-form solution was derived by implementing the mass balance equations and the generalized phenomenological filtration law, which can be used to evaluate the deposition of cement-based grout in the soil matrix. The closed-form solution relevant to a particular spherical flow was modified by a step-wise numerical calculation, considering the variable viscosity caused by a chemical reaction, and the decrease in porosity resulting from grout particle deposition in the soil pores. A series of pilot-scale chamber injection tests was performed to verify that the developed step-wise numerical calculation is able to evaluate the injectable volume of grout and the deposition of grout particles. The results of the chamber injection tests concurred well with that of the step-wise numerical calculation. Based on the filtration phenomenon, a viable approach for estimating the groutability of cement-based grout in a porous medium was also suggested, which might facilitate a new insight in the design of the grouting process. Copyright (C) 2009 John Wiley & Sons, Ltd.