탄성파를 이용한 지반 간극율 산정 = Porosity Evaluation Using Elastic Waves

다국어 초록 (Multilingual Abstract)

The reliable evaluation of design parameters in soft soils has become more important. In particular, the void ratio is an important parameter to understand the soil behavior. The objective of this paper presents the new equation for determining the porosity using elastic waves. The new equation is based on the theory of Gassmann, that is isotropic system, no chemical interaction between soil and fluid, and low frequency. The new equation is function of bulk moduli such as grain, fluid, skeleton and mixture. The bulk modulus of mixture can be estimated using elastic wave velocities, that are shear wave and compressional wave velocities. To verify the proposed equation, the specimens are prepared in the two-type calibration chambers. After measured the elastic wave, the void ratio is assessed by proposed equation. The specimens are also extracted at the top, middle and bottom part to estimate the volume based void ratio. The Foti method, which is based on the Biot theory is used to be compared with the result of new method. The calculated void ratios by proposed equation, volume based and Foti method show the good similarity. This study suggests that the proposed the new method may be a useful equation for assessing the void ratio using elastic wave velocities.