论文部分内容阅读
通过粘性泥石流体阵性流的野外观测 ,和应用最新研制的大型平板旋转式泥石流流变仪测定粘性泥石流体的应力应变特性 ,发现含有砾石的粘性泥石流体启动时具有明显的应力过冲特征。这种应力过冲特征 ,与由粘性介质阻力形变初期的剪切稀化和高浓度粗细颗粒相互挤压的内摩擦力共同组成的泥石流体的应力滞后特性 (抗剪强度 )有关。根据所测定的粘性泥石流体的准静摩擦角、正压力和动摩擦系数 ,通过剪切面上流动坡度的推导与泥石流体启动高度的演算 ,并与粘性泥石流体阵性流观测资料进行对比 ,初步揭示了粘性泥石流体阵性流的形成机理。
Through the field observation of the viscous debris fluid flow and the application of the newly developed large flat rotary rheometer, the stress-strain characteristics of the viscous debris fluid were determined. It is found that the viscous debris fluid containing gravel has obvious stress overshoot characteristics at start-up. This stress overshoot characteristic is related to the stress hysteresis characteristics (shear strength) of the debris fluid, which is composed of shear thinning at the initial stage of resistance deformation of viscous medium and internal friction which is squeezed by the high concentration of coarse and fine particles. According to the measured quasi-static friction angle, positive pressure and dynamic friction coefficient of the viscous debris fluid, the derivation of the flow slope on the shear surface and the calculation of the height of the debris flow start-up are compared with that of the viscous debris fluid array flow observation, Formation mechanism of viscous debris fluid flow.