Scale effects on viscosity determination using flume channel based on Vallejo and Scovazzo Method

¹ Department of Civil Engineering, Universitas Katolik Parahyangan, Jl. Ciumbuleuit No. 94, Bandung, Indonesia
² Undergraduate Program in Department of Civil Engineering, Universitas Katolik Parahyangan, Jl. Ciumbuleuit No. 94, Bandung, Indonesia

^* Corresponding author: tommyignatius@unpar.ac.id

Abstract

Mudflow is a type of ground movement that has a high speed and can occur suddenly. To learn more about mudflow movement, the need for analysis to obtain parameters of undrained shear strength and viscosity is important, especially viscosity, due to the limited available instruments. One approach to analysing mudflow is the rheological approach, which consists of two essential parameters: yield stress and viscosity. Research conducted by Vallejo and Scovazzo used a flume channel to determine the viscosity value of mudflow viscosity based on displacement and time of flow displacement. This study used the methods and formulas developed by Vallejo and Scovazzo with samples of kaolin and bentonite soils. The flume channels used are half-sized and quarter-sized from the original. The experimental results show that the viscosity value obtained from the Vallejo and Scovazzo Methods was relatively high because of the initial flow viscosity value. Further analysis using the Bingham plastic model shows that the viscosity obtained from the quarter-sized model was nearly 2 times smaller than the half-sized model. Meanwhile, the shear stress value of the half-sized model was about 2.3 times greater than the quarter-sized model.