Coefficient of consolidation of sandy clay

• Main Author: Kusnadi, Andhi Wijaya Harja
• Other Authors: Budi Wibawa
• Format: Final Year Project
• Language: English
• Published: 2014
• Subjects: DRNTU::Engineering::Civil engineering::Geotechnical
• Online Access: http://hdl.handle.net/10356/60001
• Institution: Nanyang Technological University

Consolidation is a major issue of geotechnical engineering due to its implications on ground settlement. Efficacy of remedial measures against excessive consolidation relies on understanding of factors affecting coefficient of consolidation. This project investigates the vertical and radial coefficient of consolidation properties of sandy clay under varying sand contents and vertical consolidation pressures. Consolidation tests were performed on moulded sandy clay samples, which are mixtures of varying proportions of clean silica sand and industrially processed kaolinite clay, by means of Rowe consolidation cells configured for vertical one-way drainage and radial drainage. Coefficients of consolidation with vertical and radial drainage were determined from both time and settlement measurements using Taylor’s square root time curve fitting method as well as from permeability and compressibility parameters of soil samples. Linear regression analyses were performed to describe the relationship between coefficients of consolidation and independent variables, which are effective consolidation pressure and sand content. Positive correlations between coefficients of consolidation and effective consolidation stress are observed. Linear regression analysis indicates that coefficient of consolidation become more positively correlated with effective consolidation stress at higher sand content. Positive correlation between coefficient of consolidation and sand content of sandy clay which becomes increasingly apparent at higher effective consolidation pressure were also evident from the experimental results. The correlations between coefficient of consolidation, effective consolidation stress, and sand content of sandy clay are found to apply for both vertical drainage consolidation and radial drainage consolidation. Furthermore, the experimental results suggest anisotropy of coefficient of consolidation, with radial coefficient of consolidation being consistently greater than vertical coefficient of consolidation.