考虑劈裂损伤的裂隙岩体注浆浆液扩散及流固耦合机理研究

The complexity of grout state and grout flow space increases the difficulty of grouting control and the effect evaluation of grouting in fractured rock mass. In this research, based on the integrated analysis of the indoor experimental data, the statistical knowledge of the grouting engineerings, the existing grouting theory and seepage theory of fractured rock mass, an unsteady grout seepage model of non-newtonian fluid in fracture network considering pressure expanding and local split fracturing will be proposed. The numerical solution of the proposed model and the corresponding hybrid and parallel hybrid finite element program will be carried out. Based on the multi information data of grouting experimental test and numerical calculation, the critical value of abrupt change of grouting pressure and the characteristics of pressure peak value, the evolution law of grout flow pattern and the attenuation law of grouting pressure with grout diffusion distance will be analyzed. Finally, referring to the in-situ grouting engineering, the statistical analysis of the filling capacity of the surrounding rock in the key grouting area of the background engineering is carried out based on the combination of active and passive methods of acoustic wave and acoustic emission testing, and digital borehole camera technique. To further reveal the migration law of grout in fractured rock mass, the influence of natural factors, engineering factors and their combination on grouting effect will be investigated. The accommodated conditions and applied scope of the proposed method in this research will be illustrated. It is expected that the research result can further enrich the grouting control theory and grouting effect evaluation method for fractured rock mass.

浆液流态和浆液流动空间的复杂性加剧了裂隙岩体注浆控制与效果评估的难度。本项目拟以既有注浆理论及裂隙岩体渗流理论为基础，并结合对室内试验数据的整合分析和裂隙岩体注浆实例的类比及规律性统计认识，尝试建立可同时考虑弹性压力扩缝和局部水力劈裂的裂隙网络非牛顿流体非稳定注浆渗流模型，并实现其数值解法、以及对应的多级混合高性能并行有限元计算程序；基于注浆试验台试验和数值计算的多元信息数据，分析不同注浆阶段的注浆压力突变临界值与峰值特征、浆液流态转变规律、注浆压力随浆液扩散距离的衰减规律等；最后依托实际注浆工程，采用声波和声发射测试的主被动联合方法、以及数字钻孔摄像技术，对关键注浆区裂隙充填性进行统计分析，研究自然因素和工程因素及其组合对注浆效果的影响，进一步揭示裂隙岩体注浆的浆液运移规律，同时界定本项目所提出方法的适用条件和适用范围。尝试进一步丰富裂隙岩体注浆理论与注浆效果分析方法。

裂隙岩体注浆，受岩体裂隙自身性质和浆液特性的影响，注浆浆脉的分布规律、扩散空间范围、封堵加固效果难以准确预测与评价，因此裂隙岩体注浆一直被认为是以经验为主的学科，也被认为是一种工艺技术。基于劈裂注浆室内实验、数值模拟、原位监测试验及相应的理论分析，本项目着重开展了考虑劈裂损伤的裂隙岩体注浆浆液扩散及流固耦合机理研究，主要研究成果体现在如下三个方面：（1）提出了倾斜粗糙岩体裂隙黏变浆液扩散理论模型及多向扇形空间分步计算方法，研究了裂隙倾角、裂隙粗糙度、时变黏度等多因素影响下的浆液扩散特征，揭示了幂律型浆液在标准JRC裂隙中的水力特性；（2）建立了考虑流固耦合的随机粗糙裂隙与岩基协调变形的浆液扩散模型，研究了基于有效隙宽的注浆压力分析方法，揭示了高压浆液作用下裂隙粗糙壁面应力集中及局部劈裂响应机制；（3）基于注浆过程中岩体损伤演化与浆液扩散机理的认识，提出了基于微震监测的浆液劈裂扩散识别与岩体质量改造效果评价方法，并初步应用于工程实践，解释了注浆压力波动、MS特征与浆液扩散范围、岩体质量的对应关系。历时四年研究，本项目累计发表学术论文16篇、授权发明专利4项（其中成果转化1项）、获得软件著作权3项、获得省部级科技奖励2项、培养研究生7名。本项目的研究成果对深入认识注浆裂隙劈裂效应、揭示浆液在岩体裂隙中的流动特性、识别其扩散范围而对注浆效果进行精细评价，具有重要科学意义。在深入认识裂隙岩体注浆浆液的运移规律基础之上，本项目研究成果对于发展切实可行的裂隙岩体注浆浆液扩散识别与加固评价技术、指导注浆工程实践，亦具有一定参考价值。