INFLUENCE OF CLAY FRACTION ON VISCOSITY IN RELATION TO MUDFLOW
DOI:
https://doi.org/10.11113/mjce.v25.15866Keywords:
mudflow, water content, liquid limit, viscosityAbstract
Mudflow is one type of natural disaster. This type of mass movement can be triggered by changing of water content due to increasing of rainfall intensity. The occurrence in Indonesia and Taiwan is relatively high. According to its definition, the material is dominant by fine grained soil. The viscosity as one of main rheology parameters governs mudflow movement. In order to overcome the conventional viscometer which could not measure around liquid limit, the authors developed a new laboratory test so called the flow box test (FBT). The governing equation is a couple of Terzaghi’s trap door and Bingham model. From this test, one of the merit is this test can measure the viscosity around liquid limit. Using the case study in Indonesia (Ciwidey and Karangayar) and Taiwan (Maokong), the result shows that increasing of clay fraction is followed by increasing of viscosity. Hence, this research has a contribution to explain the influence of clay fraction on viscosity in relation to mudflow.References
Chen, C.L. (1988) General solutions for viscoplastic debris flow. J. Hydraulic Engineering, 114(3): 259-282.
Cruden, D.M., and Varnes, D.J. (1996) Landslide types and processes, In: A.K. Turner and R.L. Shuster (eds.), Landslides: investigation and mitigation, Transp. Res. Board., Spec. Rep., 247, 36-75.
Franzi, L. (2000) On the effect of clays on collisional stresses in debris flow, Proc. 2nd IAHR Symposium on river, coastal and estuarine morphodynamics, Obihiro, Japan, 375-384.
Huang, X. and Garcia, M.H. (1998) A Herschel-Bulkley model for mud flow down a slope. J. Fluid Mech., 374:305-333.
Hungr, O., Evans, S.G., Bovis, M.J. ,and Hutchinson, J.N. (2001) A review of the classification of landslides of the flow type.†Environmental and Eng. Geoscience, VII(3): 221-238.
Krizek, R.J. (2004) Slurries in geotechnical engineering. 12th Spencer J. Buchanan Lecture, Texas: Texas A&M University.
Lee, C.J., Wu, B.R., Chen, H.T. and Chiang, K.H. (2006) Tunnel stability and arching effects during tunneling in soft clayey soil, Tunnelling and Underground Space Technology, 21:119-132.
Lorenzini, G & Mazza, N. (2004) Debris flow phenomology and rheological modelling. Boston: WIT Press.
Takahashi, T. (2007) Debris flow: mechanics, prediction and countermeasures. London: Taylor and Francis.
Terzaghi, K. (1943) Arching in ideal soils. In: Theoretical Soil Mechanics. New York: John Wiley & Sons.
Widjaja, B. and Lee, S.H.H (2012) Flow box test for the viscosity of soil in plastic and viscous liquid states. Soils and Foundations (under review).
