摘要
为研究水流对含贯通裂缝软弱夹层的冲刷效应,对含贯通裂缝的软弱夹层建立了无限延伸的径流-渗流耦合水力冲刷模型。该模型用Navier-Stokes方程描述裂缝通道中的裂缝水流,用Brinkman-extended Darcy方程描述软弱夹层中岩土体渗流,然后根据不同介质交界面处流速相等及剪应力连续的边界条件来推求各个介质中的流速分布。根据土颗粒起动破坏时的流速与土颗粒受力的数学关系,推导出裂缝底部土颗粒起动时的临界起动速度;考虑底部土颗粒受水流冲刷时的摩阻效应,结合径流-渗流耦合水力冲刷模型,得出裂缝通道底部的土颗粒受水流冲刷破坏时的临界水深。分析表明,临界水深随着颗粒的重度和颗粒间的黏聚力的增大而增大,随着裂缝通道的坡度、岩土体的孔隙率和渗透率的增大而减小。
In order to study the scouring effect of water flow on the weak interlayer with continuous cracks,an infinitely extended runoff-seepage coupled hydraulic scouring model is established. The model uses the Navier-Stokes equation to describe the fracture flow in the fracture channel,and uses the Brinkman-extended Darcy equation to describe the seepage of the rock and soil in the weak interlayer. Then,based on the boundary conditions of equal flow velocity and continuous shear stress at the interface of different media,the velocity distribution in each medium is derived. According to the mathematical relationship between the incipient flow velocity and the force,the critical incipient velocity of the soil particles at the bottom of the crack is derived. Considering the friction effect of the bottom soil particles washed by the water flow and combined runoff-seepage coupled hydraulic erosion model,solving the critical depth of the soil particles at the bottom of the crack channel when washed by water flow. The analysis shows that the critical water depth increases with the weight of the particles and the cohesive force between the particles,and decreases with the slope of the crack channel,the porosity and permeability of the rock mass.
作者
朱崇林
雷孝章
符文熹
叶飞
ZHU Chong-lin;LEI Xiao-zhang;FU Wen-xi;YE Fei(College of Water Resources and Hydropower,Sichuan University,Chengdu 610065,China;State Key Laboratory of Hydraulics and Mountain River Protection,Chengdu 610065,China)
出处
《中国农村水利水电》
北大核心
2019年第2期139-143,154,共6页
China Rural Water and Hydropower
基金
国家自然科学基金项目(41772321)
四川省国际合作项目(2018HH0082)
中国地质调查局基础地质调查项目(DD20160272)
关键词
贯通裂缝
水力冲刷
径流-渗流耦合
临界水深
continuous crack
hydraulic erosion
runoff-seepage coupling
critical depth
