Author/Authors :
abd jalil, juliana unversiti kebangsaan malaysia - faculty of engineering and built environment - department of civil structural engineering, Bangi, Malaysia , wan mohtar, wan hanna melini unversiti kebangsaan malaysia - faculty of engineering and built environment - department of civil structural engineering, Bangi, Malaysia , mohamod, mohd tajuddin unversiti kebangsaan malaysia - faculty of engineering and built environment - department of civil structural engineering, Bangi, Malaysia , nawang, siti aminah bassa unversiti kebangsaan malaysia - faculty of engineering and built environment - department of civil structural engineering, Bangi, Malaysia , ahmad, azman unversiti kebangsaan malaysia - faculty of engineering and built environment - department of civil structural engineering, Bangi, Malaysia , ming, tey jit unversiti kebangsaan malaysia - faculty of engineering and built environment - department of civil structural engineering, Bangi, Malaysia
Abstract :
Visual observation is the most common method to define the incipient sediment motion to-date. However, the definition can be subjective between researchers, whereby the incipient or threshold criteria of sediment motion depends on the interpretation when the sediment becomes mobile from the state of immobility. This study attempt to investigate the variation of incipient sediment motion value over varying sediment sizes due to subjectivity effect. Three observers with different research background individually determined the critical shear stress, using the same definition of threshold critera. The Shields profile obtained was similar for coarser particles and started to deviate for fine sediment region. This paper found that the existence of variation in the incipient sediment motion, in particular for finer sediment size, with particle Reynolds number Re* 10.
