摘要
在地下工程中,注浆技术是修复裂隙岩体和封堵地下水的重要手段。了解浆液在岩石裂隙中的流动行为对优化注浆方案有重要意义。通过可视化试验研究了粗糙裂隙中浆液性质对注浆过程的影响规律,提出了驱替模式试验相图,并阐明了其细观机制。试验结果表明,浆液的驱替行为与传统牛顿流体不同,注浆速度和浆液质量分数显著影响粗糙裂隙中浆液的驱替模式;在浆液的驱替过程中,浆液流变性质和裂隙开度变异性的共同作用及其相互反馈影响引起的黏度变化是形成不同驱替模式的重要原因;注浆流速越小,浆液质量分数越大,两相界面越稳定,浆液最终填充率越高;驱替过程中浆液难以完全填充裂隙的较小开度区域,且随着注浆流量的增加,浆液最终填充率呈现明显的非单调性;浆液最终填充率受驱替形态的影响显著,基于界面稳定分析理论,推导了浆液在粗糙裂隙中驱替形态转变的临界条件。该研究成果揭示了粗糙裂隙中浆液扩散的机制,可为评价与控制岩体注浆效果提供参考依据与技术思路。
In subsurface engineering,grouting is an important measure to seal or strengthen fractured rock mass and reduce groundwater flow.Understanding the grout flow in rock fractures is significant to improve the grouting efficiency.The influence of grout material property on the grouting process in rock fractures saturated with a resident fluid is studied by visualized experiments.We present an experimental phase diagram of pattern formation and elucidate the relevant microscopic mechanisms.The experimental results show that the injection velocity and mass fraction in the grout significantly influence the displacement patterns in rough fractures,which is different from the displacement behavior with Newtonian fluid.During the displacement,the formation of different patterns is attributed to the local viscosity heterogeneity induced by the coupling effect of shear-thinning behavior and the spatial variability of fracture apertures.Decreasing injection velocity or increasing the mass fraction would stabilize the fluid-fluid interface and increase the area of initial stable region.The narrower aperture region of the fracture can only to be partially filled(with a low filling rate)by the polymer solution,except under the condition of very low flow rate and high mass fraction.The grout filling rate exhibits non-monotonicity with respect to flow rates.The displacement efficiency is significantly affected by displacement patterns,and thus we propose a theoretical model based on the interface stability analysis to elucidate the mechanisms behind the transition of displacement patterns.This work improves the fundamental understanding of grout flow in rough fractures and can provide a reference and technical guidance for evaluation and control of grouting efficiency in engineering practice.
作者
张乐
杨志兵
李东奇
陈益峰
ZHANG Le;YANG Zhi-bing;LI Dong-qi;CHEN Yi-feng(State Key Laboratory of Water Resources and Hydropower Engineering Science,Wuhan University,Wuhan,Hubei 430072,China;Key Laboratory of Rock Mechanics in Hydraulic Structural Engineering of the Ministry of Education,Wuhan University,Wuhan,Hubei 430072,China)
出处
《岩土力学》
EI
CAS
CSCD
北大核心
2023年第6期1708-1718,共11页
Rock and Soil Mechanics
基金
国家自然科学基金(No.42077177,No.51925906)。
关键词
粗糙裂隙
注浆
可视化试验
两相流
rough fracture
grouting
visualized experiment
two-phase flow
