사질토의 변형계수에 미치는 고결영향 분석

Abstract

This study investigates the effect of cementation on deformation characteristics of sands such as small-strain shear modulus (Gmax), dilatometer modulus (ED or MD), and constrained modulus (M). A series of DMT and bender element tests are performed on cemented sands prepared in calibration chamber, and one dimensional compression tests in oedometer cell are conducted. It is shown from the test results that, as the cementation degree increases, Gmax increases exponentially while M and ED increase almost linearly. Among three moduli, Gmax appears most sensitive to the cementation while ED is least sensitive due to the damage of cementation bonds induced during DMT penetration. It is also observed that MD significantly underestimates M of cemented sand. Although both cemented and un-cemented sands show similar decreasing trends of Gmax/MD with increasing KD, the cementation induces the significant increase in Gmax/MD value. Therefore, it is expected that Gmax/MD-KD relation can be used to determine if the deposit is cemented or not.