부산점토의 점소성 압밀거동 특성

Abstract

In order to analyze viscopastic characteristics of Busan clay, several series of constant rate of strain (CRS) consolidation tests with different strain rates were carried out on both vertical and horizontal drainage conditions and long-term consolidation tests were performed. From experimental test results on soft Busan clay, it was found that the preconsolidation pressure depended on the corresponding strain rate occurred during consolidation process. In addition, consolidation curves normalized with respect to preconsolidation pressure gave a unique stress-strain curve. Coefficient of consolidation and permeability estimated from CRS test had a tendency to converge to a certain value at normally consolidated range regardless of strain rate. The Ch/Cv and kh/kv values gradually decreased in overconsolidated region and had a tendency to converge to a certain value at normally consolidated region. A long-term consolidation characteristic of Busan clay was also investigated from long-term oedometer tests for 20 days. As a result, secondary compression index and creep rate with time were investigated in stress conditions of overconsolidated or normally consolidated states. And then the values of Cc, Cs and Ca of Busan clay were analyzed to look into their relations.