Material Strength Characteristics of Reservoir Embankment for Irrigation in Aomori Prefecture

Abstract

Material strength characteristics (internal frictional angle φ, cohesion c) of a reservoir embankment for irrigation in Aomori prefecture were assessed using conventional direct shear test (DST) and in-situ vane-cone shear test (VCST). Based on the main physical properties of natural water content (ω), fine fraction content (F_c) and the dry density (γ_d), many reservoir embankments have been constructed using foundation ground material obtained near the reservoir. The shear stress ratio (τ/σ_v) was found to be convergent, around 0.5, with increased vertical stress (σ_v) in DST. Much of the vertical displacement tended to move the compression side. Because many values of τ/σ_v in VCST were scattered, we were able to infer some difficulties within the range of experimental accuracy. Although no correlation was found by φ_d in DST and φ_v in VCST, the values of c_d in DST were higher than c_v in VCST. Furthermore, a certain degree of correlation of φ_d × γ_d to F_c/ω was confirmed.