伴随我国煤矿开采深度逐渐增加，工作面掘进面临的硬岩强度逐渐提升，而现有硬岩巷道掘进技术存在着截齿磨损严重、施工效率低下的问题。本研究根据传统机械切割方式所存在的外置式磨料水射流辅助切割中远距离射流能量衰减机理不明确、射流水压不足及连续供给磨料稳定性差的问题，通过基于理论研究、室内实验验证与数值仿真技术相结合的研究方法，为验证远距离磨料水射流破岩效果的可行性，设计研发连续供砂前混式高压磨料水射流设备，对远距离射流破岩效能优化机制进行系统探讨，主要结论如下：

（1）通过设计连续供砂前混式磨料高压水射流设备，为了解决连续磨料供给性差和前混式磨料水射流设备水压不足的问题；通过设计新型连续供砂系统，采用了双置高压罐优化传统水射流设备的单置高压罐方案，实现了双置高压罐A罐进行磨料水射流工作的同时对B罐进行磨料供给，达到水射流设备连续供砂持续破岩的效果；通过设计新型高压柱塞泵，改善了传统高压柱塞泵对纯水的加压效果不足的问题，提升了磨料与纯水的混合程度及射流速度；通过水射流理论运算，优化了前混式磨料高压水射流设备喷嘴口径，提升了设备稳定性。

（2）本研究聚焦于高压水射流作用于岩体时产生的水锤效应机理。通过构建弹性波在岩体介质中的传播模型，系统解析了瞬态冲击载荷下岩石内部动应力的分布特征。定量研究了径向动应力、切向动应力与剪切动应力与水锤压力峰值、冲击点径向距离等关键参数呈现显著相关性。进一步结合岩石动态抗拉强度和抗剪强度的失效准则，推导出破碎区半径的解析表达式；基于不可压缩牛顿假设和质量守恒原理，建立了轴对称磨料水射流的扩散和消散方程，推导出射流截面积与轴向速度的平方成反比，表明水流速度、颗粒动能和冲击压力都成第四次幂随着射流方向急剧下降。

（3）通过ANSYS/LS-DYNA软件，采用SPH-FEM多尺度耦合建模技术，对磨料射流冲击破岩过程进行三维动态仿真。重点研究射流速度和射流角度对岩体破坏模式间的映射关系，模拟结果表明：不同的射流速度、射流角度以及岩石类型对破岩效果有显著影响；在较高的射流速度下，水射流的破岩深度显著增加，同时射流角度对裂纹扩展也有重要影响。为磨料水射流破岩技术的进

一步优化提供了数值支持，也验证了理论模型的正确性和有效性，为实际应用中的参数选择提供了参考依据。

（4）采用自主研发的二维磨料水射流模拟程序，通过构建二维耦合模型，针对磨料水射流作用下岩体破裂特征开展了多工况模拟与机理分析，系统考察了泵压、浓度、角度及喷头布设对破裂效果的影响，并结合应变云图与流场演化图像，揭示了射流破裂的深宽协同演变机制。在理论建模方面，基于动压作用、颗粒撞击动能与剪切扰动等模型阐释了多物理场共同驱动下的破裂机理，并归纳了影响破裂效率的关键因素。研究结果为后续参数优化与装置布设提供了依据，也为复杂环境下高效破岩技术的推广奠定了理论基础。

（5）通过采用自主研发前混式磨料高压水射流设备，采用了单因素试验分析法，设计对比试验，分别分析了近距离及远距离的靶距、泵压、磨料浓度及射流角度对混凝土实验试块破坏宽度和破环深度的影响程度，得到了各个参数对实验结果的影响权重；采用了正交实验和极差分析，分析了靶距、泵压、磨料浓度及射流角度对实验结果的影响权重，得到最优参数组合；采用异形喷口的对比实验，得到了采用平口射流会导致中心区穿透力减弱切割深度降低，扩散的同时能量过分衰减导致切割宽度同样远远不如直射流的结果。最终通过对现场试验结果的系统性分析，验证了远距离磨料水射流破岩的可行性。

With the gradual increase of coal mining depth in China, the strength of hard rock faced by working face excavation is gradually increasing, and the existing hard rock roadway excavation technology has the problems of serious pick wear and low construction efficiency. In this study, according to the problems of unclear energy attenuation mechanism of long-distance jet, insufficient jet water pressure and poor stability of continuous abrasive supply in traditional mechanical cutting methods, through theoretical analysis, laboratory experiments and numerical simulation, in order to verify the feasibility of long-distance abrasive water jet rock breaking effect, a continuous sand supply pre-mixed high-pressure abrasive water jet equipment was designed and developed, and the optimization mechanism of long-distance jet rock breaking efficiency was systematically discussed. The main conclusions are as follows :

(1)In order to solve the problem of poor supply of continuous abrasive and insufficient water pressure of pre-mixed abrasive water jet equipment, the pre-mixed abrasive high-pressure water jet equipment for continuous sand supply is designed. By designing a new type of continuous sand supply system, a single high-pressure tank scheme with double high-pressure tanks is adopted to optimize the traditional water jet equipment, which realizes the abrasive water jet work of the double high-pressure tank A and the abrasive supply of the B tank, so as to achieve the effect of continuous sand supply and continuous rock breaking of the water jet equipment. By designing a new type of high-pressure plunger pump, the problem of insufficient pressure effect of traditional high-pressure plunger pump on pure water is improved, and the mixing degree and jet velocity of abrasive and pure water are improved. Through the theoretical calculation of water jet, the nozzle diameter of the pre-mixed abrasive high-pressure water jet equipment is optimized, and the stability of the equipment is improved.

(2)This study focuses on the mechanism of water hammer effect when high pressure water jet acts on rock mass. By constructing the propagation model of elastic wave in rock medium, the distribution characteristics of dynamic stress in rock under transient impact load are systematically analyzed. The significant correlation between radial dynamic stress, tangential dynamic stress and shear dynamic stress and key parameters such as water hammer pressure peak and radial distance of impact point is quantitatively studied. Combined with the failure criteria of rock dynamic tensile strength and shear strength, the analytical expression of the radius of the fracture zone is derived. Based on the incompressible Newton hypothesis and the principle of mass conservation, the diffusion and dissipation equations of axisymmetric abrasive water jet are established. It is deduced that the cross-sectional area of the jet is inversely proportional to the square of the axial velocity, indicating that the water flow velocity, particle kinetic energy and impact pressure all decrease sharply with the jet direction in the fourth power.

(3)Through ANSYS / LS-DYNA software, SPH-FEM multi-scale coupling modeling technology is used to simulate the abrasive. Three-dimensional dynamic simulation of jet impact rock breaking process. The mapping relationship between jet velocity and jet angle on rock failure mode is studied. The simulation results show that different jet velocity, jet angle and rock type have significant influence on rock breaking effect. At higher jet velocity, the rock breaking depth of water jet increases significantly, and the jet angle also has an important influence on crack propagation.

(4)By using the self-developed two-dimensional abrasive water jet simulation program and constructing a two-dimensional coupling model, the multi-condition simulation and mechanism analysis were carried out for the fracture characteristics of rock mass under the action of abrasive water jet. The effects of pump pressure, concentration, angle and nozzle layout on the fracture effect were systematically investigated. Combined with the strain cloud diagram and flow field evolution image, the depth-width synergistic evolution mechanism of jet fracture was revealed. In terms of theoretical modeling, based on the models of dynamic pressure, particle impact kinetic energy and shear disturbance, the fracture mechanism driven by multiple physical fields is explained, and the key factors affecting the fracture efficiency are summarized. The research results provide a basis for subsequent parameter optimization and device layout, and also lay a theoretical foundation for the promotion of efficient rock breaking technology in complex environments.

(5)Through the use of self-developed pre-mixed abrasive high-pressure water jet equipment, a single-factor test analysis method was used to design a comparative test. The influence of target distance, pump pressure, abrasive concentration and jet angle on the damage width and damage depth of the concrete test block was analyzed, and the influence weight of each parameter on the experimental results was obtained. Orthogonal experiment and range analysis were used to analyze the influence weight of target distance, pump pressure, abrasive concentration and jet angle on the experimental results, and the optimal parameter combination was obtained. Using the contrast experiment of the special-shaped nozzle, it is obtained that the use of the flat nozzle jet will lead to the weakening of the penetration force in the central area and the reduction of the cutting depth. At the same time, the excessive attenuation of energy leads to the cutting width is also far less than the direct jet. Finally, through the systematic analysis of the field test results, the feasibility of long-distance abrasive water jet rock breaking is verified.