高压水射流冲击作用下横观各向同性岩石破碎机制

BREAKAGE MECHANISM OF TRANSVERSE ISOTROPIC ROCK SUBJECTED TO HIGH-PRESSURE WATER JET

基于流体动力学与弹性力学基本理论,分析水射流冲击岩石过程中产生的水锤压力与滞止压力,推导不同压力阶段水射流截面上动压力径向分布函数,建立水射流以不同的夹角α冲击横观各向同性岩石的数学模型,选取α=0°,45°,90°研究冲击夹角对岩石破碎规律的影响;选择具有良好横观各向同性的砂岩开展不同夹角的冲击实验。理论分析与实验研究表明:水锤压力导致横观各向同性岩石产生冲击破碎坑,滞止压力诱发岩石内部裂纹的产生与扩展;水射流以垂直于、倾斜于、平行于层理冲击横观各向同性岩石导致其分别产生横向裂纹、倾斜裂纹和劈裂裂纹。

The water hammer pressure and stagnation pressure during the impacting process of water-jets were analyzed based on the theories of hydrodynamics and elasticity. Radial distribution functions for the dynamic pressure in the cross-sections of water-jets during different pressure stages were derived. Numerical models for the transverse isotropic rocks under water jet impacting at different angles were developed and the influence of impact angle on the breaking of rocks was studied assuming α = 0 °, 45 °, 90 °. A number of impacting experiments on the transverse isotropic sand-stones were conducted at different impacting angles. The numerical analysis and the experiments reveal that the water hammer pressure produced broken pits on the transverse isotropic rocks and the stagnation pressure caused the initiation and development of cracks inside the rocks. The transverse cracks, inclined cracks and splitting cracks appeared accordingly when the water-jets impacting were perpendicular, inclined and parallel to the beddings of the transverse isotropic rocks.