在含黏性土砂层注浆工程中，劈裂-压密模式是其主要注浆模式，而目前的砂层注浆设计理论大多基于渗透模式，难以适用于含黏性土砂层的注浆设计。本项目拟采用理论分析、室内试验和物理模拟试验相结合的方法，针对含黏性土砂层劈裂-压密注浆模式开展研究。基于多因素全面注浆试验，研究砂层渗透可注性条件与注浆起劈条件，建立劈裂-压密注浆模式的发生判据；研究浆液流动与砂层压密变形之间的界面应力耦合效应，开发注浆扩散过程迭代算法，分析单一序次与多序次浆脉的空间形态特征，揭示含黏性土砂层劈裂-压密注浆扩散规律；研究压密效应对含黏性土砂层性能的强化作用，提出劈裂-压密注浆加固体宏观性能指标的等效计算方法，分析注浆加固体性能的各向异性与空间衰减特征，揭示浆脉骨架与压密砂层的协同加固机制。研究成果有助于补充和完善砂层注浆控制理论，为含黏性土砂层劈裂-压密注浆设计提供理论依据。

Fracture- compaction mode is the main grouting mode in grouting engineering projects for clayey sand. However, current sand grouting design method is based on permeation mode, which is hard to guide grouting design in clayey sand. In this project, many research methods, such as theoretical analysis, laboratory test and physical simulation test, will be adopted to study fracture- compaction grouting mode in clayey sand. Based on laboratory tests of sand injectability and fracturing critical condition, occurrence conditions of fracture- compaction grouting mode will be acquired. To study interfacial stress coupling effect between grout flow and sand compaction deformation, new algorithm for calculating grouting process will be developed. Spatial shape characteristics of grouted body will be analyzed which is composed of grout vein, compacted sand and original sand. Fracture-compaction grouting diffusion law will be revealed. Growth of clayey sand performance originated from compaction effect will be tested. Equivalent calculation method for performance parameters of fracture- compaction grouted body will be studied and put forward. Based on analysis of anisotropy and spatial attenuation characteristics of performance of grouted body, synergistic reinforcement mechanism of grout vein and compacted sand will be revealed. Research results are helpful to complement sand grouting theory, and provide the theoretical basis for fracture- compaction grouting design in clayey sand.