| Summary: | 碩士 === 國立成功大學 === 水利及海洋工程學系碩博士班 === 96 === Debris flow consists of mud, sand, gravel, and other solid materials mixed with water；therefore, its the rheological property depends on particle concentration, particle size distribution, and mineral composition. The Carbopol-940 slurry (acrylic polymer slurry) was used to simulate debris-flow slurry in the present study. The rheological properties of the Carbopol-940 slurry were measures first, and then the rheological properties of the mixtures of gravel-slurry that were formed by adding glass beads(5mm,10mm,16mm) and polystyrene particles(5mm) into the Carbopol-940 slurries respectively, were measured. The experimental results show that: (1) Both rheological properties of the Carbopol-940 slurry and the gravel-slurry mixtures could be described by the Bingham model, with rheological parameters (Bingham yield stress and Bingham viscosity) varied with particle concentration and particle size； (2) Under the same shearing rate (≦20 s-1), the Bingham yield stress and Bingham viscosity increased with the increase of particles concentration; (3) Under the same particle concentration of the gravel-slurry mixture, the smaller-size particles had larger influence on the Bingham yield stress and viscosity; (4) When the Carbopol-940 slurry had higher viscosity, the effect of the particle density on the Bingham yield stress and Bingham viscosity is not significant; (5) Non-uniform size of particles added in to the slurry resulted in greater increases of the Bingham yield stress and Bingham viscosity, compared with that added with uniform size particles. ; (6) Under the same particle concentration, the increase of Bingham yield stress could be 10%~30%, and the increase of Bingham viscosity could be 20~70% for the mixtures of two particle sizes in which the finer particles content was about 25% to 70%, compared with those for mixtures of uniform finer particles.
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