벤더엘리먼트와 삼축시험을 통한 모래의 전단강도 및 포아송비 특성 규명

초록

In this paper, isotropically consolidated drained triaxial compression test device installed with bender elements is usedto measure stress, stain, and shear wave velocity, from which the characteristics of shear strength and Poisson’ratio areinvestigated. The results show that there is a unique relationship between maximum shear modulus determined from shearwave velocity and effective vertical stress at failure, which is defined as the sum of vertical and radial stresses at failure. The correlation is very useful since it is possible to predict the shear strength and internal friction angle from shearwave velocity. In addition, Poisson’s ratio is determined from measured axial and volumetric strains. It is demonstratedthat the range of measured Poisson’s ratio is between 0.15 and 0.6, and increases with the axial strain. The ratios ataxial strains smaller than 0.2% corresponds to the range recommended in design codes, which are approximately from0.3～0.35. However, at axial strains exceeding 1%, the measured ratios are between 0.5 and 0.6. It is therefore shownthat use of ratios commonly used in practice will result in pronounced underestimation at large strains.

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