高压水射流破岩能量耗散与释放机制

发布时间：2018-04-15 22:04

本文选题：水射流 + 破岩　；参考：《煤炭学报》2017年10期

【摘要】：从应力-应变角度建立的高压水射流破岩准则,其精确度取决于对屈服应力的表述,由于表达式中不含材料参数,不能精确计算高压水射流破岩参数,而从能量角度建立的岩石强度理论具有更好的适用性和准确性。开展了基于能量耗散和释放机制的高压水射流破岩机理,理论研究了自由射流段速度分布特征,分别计算了等速核区和射流边界层扩展区动能,建立了不同靶距处射流动能计算模型。高压水射流冲击破岩能量表征为冲蚀坑的形成和岩体的体积破坏;射流能量耗散于剪切面的扩展和滑动,储存弹性势能的释放导致岩体的整体体积破坏。根据岩石的统一能量屈服准则,建立了高压水射流破岩能量准则。通过砂岩、灰岩和花岗岩的单轴压缩应力-应变曲线得出3种岩石的材料参数,计算每种岩石的剪切应变能和体积应变能,得出射流破岩临界速度。根据高压水射流冲击破岩实验结果修正了考虑喷嘴流量系数的高压水射流破岩能量准则,该准则能够较为精确的计算射流破岩速度。且岩体的破坏形态证明从能量角度研究破岩机理更为适合。
[Abstract]:The accuracy of rock breaking criterion of high pressure water jet from stress-strain angle depends on the expression of yield stress. Because the expression does not contain material parameters, the rock breaking parameters of high pressure water jet can not be calculated accurately.The rock strength theory established from the angle of energy has better applicability and accuracy.Based on the mechanism of energy dissipation and release, the rock breaking mechanism of high pressure water jet is developed. The velocity distribution characteristics of free jet section are theoretically studied, and the kinetic energy of isokinetic core region and jet boundary layer expansion zone are calculated, respectively.The kinetic energy model of jet at different target distances is established.The impingement energy of high pressure water jet is characterized by the formation of erosion pits and the volume failure of rock mass, while the expansion and sliding of jet energy dissipation on the shear plane and the release of storage elastic potential energy lead to the overall volume failure of rock mass.According to the unified energy yield criterion of rock, the energy criterion of rock breakage by high pressure water jet is established.Through uniaxial compression stress-strain curves of sandstone, limestone and granite, the material parameters of three kinds of rocks are obtained, the shear strain energy and volume strain energy of each rock are calculated, and the critical velocity of rock breakage by jet is obtained.According to the experimental results of high pressure water jet impingement and rock breaking, the rock breaking energy criterion of high pressure water jet considering nozzle flow coefficient is revised, which can calculate the rock breaking velocity of jet more accurately.The failure pattern of rock mass proves that it is more suitable to study the mechanism of rock breaking from the angle of energy.
【作者单位】：河南理工大学瓦斯地质与瓦斯治理国家重点实验室培育基地;煤炭安全生产河南省协同创新中心;河南理工大学安全技术培训学院;
【基金】：国家重点研发计划资助项目(2017YFC0804207) 国家自然科学基金资助项目(51704096) 教育部创新团队发展支持计划资助项目(IRT_16R22)
【分类号】：TU45

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