Nonlinear Compression Characteristics of Highly Plastic Clays and Silts of Korea South Coast

Hong, Seok-Woo; Im, Jong-Chul

Journal of Navigation and Port Research 2012;36(2):181-187.
Published online March 31, 2012.

한국 남부 해안 고소성 점토 및 실트의 비선형 압축특성 연구

홍석우, 임종철

Nonlinear Compression Characteristics of Highly Plastic Clays and Silts of Korea South Coast

Seok-Woo Hong, Jong-Chul Im

Abstract

Highly plastic clays in their normally consolidated states are not always linear but are concave downwards. Thus their compression index deceases with the increase of consolidation pressure. The e-log σ_υ′ curves of plastic or non-plastic silty clays are not linear but are convex upwards. In this paper, consolidation tests were conducted with several undisturbed field soils of Korea south coast and their e-log σ_υ′ plots are not always linear. In case of using Butterfield's method(liquid limit 50 ～ 100%), lnυ-lnσ_υ′ plots are linear. But some undisturbed samples which have void ratio over 2.24, liquid limit over 100% and plasticity index over 60% are not linear. In results of consolidation tests with remolded samples which contain silt(fly ash) contents of 90% has compression index increasing with the increase in consolidation pressure.

Key Words: nonlinear compression index;highly plastic clay;plastic silt;non-plastic silt;improved compression index