中文摘要：

基于散体介质理论的颗粒流分析方法,运用其内置的Fish语言定义流体域,建立了流动方程和压力方程。同时,针对具有凝聚力的致密土体,引入颗粒接触黏结模型,建立能反映颗粒体与流体域耦合作用的土体注浆颗粒流模型。在此基础上,通过数值仿真试验,对土体劈裂注浆过程进行细观模拟研究,分别对比了不同注浆压力和不同土体性质下浆体压力扩散及劈裂缝的发生、发展规律。模拟结果表明：注浆压力是影响土体改性效果的主要因素,但实际应用中注浆压力的确定,应以浆脉网络的形成为标志,合理控制最大压力。一定注浆压力下,土体颗粒的粒径比,颗粒间的摩擦系数及颗粒之间的黏结强度等细观参数对土体注浆后的宏观力学行为有比较明显的影响。这些结论与土体劈裂注浆现场试验及理论分析相吻合,验证了颗粒流模拟土体劈裂注浆过程的可行性,对注浆机理有了更深入的理解,研究成果对从微观领域研究注浆理论奠定了基础。

英文摘要：

Based on the theory of particle flow,the domain of flow is defined by using the Fish language implemented in PFC,and the formulas for flow and pressure are put forward respectively.Furthermore,the contact-bond model is introduced due to the complicated properties of low permeability soil to establish PFC model,which can reflect Fluid-solid coupling between particle flow and flow domain.Based on the above study,the process of fracture grouting in soil is simulated from the micro-viewpoint under coupling environment.In addition,the emergence and development of crack and grouting pressure in soil is analyzed under different grouting pressures and soil properties.The research results show that pressure plays a key role in consolidating the soil by fracture grouting,but in fact it should be kept in a reasonable value in order to form grouting slurry net entirely.Under certain grouting pressure,it indicates that the macroscopic response of grouting in soil is related to microscopic parameters of soil,such as particle size ratio,friction,and bond properties.The conclusion of numerical simulation agrees well with the field tests and grouting theory.The meaning of this research lies in the fact that PFC can make the microcosmic research of fracture grouting in soil possible and lead to a further understanding of grouting mechanism in soil.The research will be helpful to the application of PFC to the theoretical studies on grouting in the future.