摘要
含有松散的固体颗粒的流体,不是连续介质.本文用流变方程式来表达泥石流运动,仅是一种概念性的模拟.用颗粒之间撞击的概念说明了泥石流运动类型及其转化.说明了Bag-nold的试验结果与Smoluchowski的撞击理论相一致.流变方程式τ=B+Cdu/dy=B+K(du/dy)~2中,阻力分为两部份,一部份为颗粒之间的静阻力B,一部份为颗粒撞击而产生的阻力.进而推导得到流速垂线分布和平均流速.说明底部有一个“作用流速”,才产生底床的冲刷与淤积.基于作用力与阻力相平衡的原理,泥石流流速公式可用Chezy或Manning公式形式来表达.而流速系数有关因素很多,十分复杂,表现出地域性的差别很大.基于与的物理意义,在泥石流运动过程的部份时段内,和部份断面间距内为层移运动,与之间存在函数关系,输沙率可以用Bagnold,Yalin,Meyer-Peter等公式来计算,并用实测资料来校核.
Since the fluid containing discrete solid particles is not acontinuum, the rhcologic equation to express the debris flow is only a conceptional simulation. Basing on the field measured data and using the kinetic theory of collision of solid particles, the classification of flow patterns of debris flow and the transformation of flow paterns are explained. The Bagnold's experimental results about the dispersion effect and the Smoluchowski's theory of collision of solid particles are examined to be the same physical implication. In the equation of motion τ=B + Gdu/dy=B + K(du/dy)2 ,the friction is composed of two parts, the static friction stress B and the kinetic friction stress Gdu/dy due to the collision of particles. The distribution ofvelocity along the vertical and the average velocity for different patterns of debris flow are derived. It is assumed that there is an 'effective bed velocity' on the bottom which determines the erosion and deposition of the bed. Since the formulas of velocity are established on the basis of balance of action and reaction which take the Chezy's or the Manning's form are realistic. However,the coefficients of velocity formulas are rather complicate. So the coefficients of velocity formulas reveal the diverse of the formulas for different regions. Basing on the physical meanings of,for debris flow with laminated motion, there is the functional relation between Φ and . The rate of transportation of coarse solid particles can be computed by Bagnold's, Yalin's and Meyer-Petter's formulas checking with field measured data.
出处
《泥沙研究》
CSCD
北大核心
1991年第4期30-38,共9页
Journal of Sediment Research
