Oedometer Test Data Interpretation Workbook

The Oedometer Test Data Interpretation Workbook serves as both a pedagogical tool and a field-ready reference for interpreting results from standard oedometer (consolidometer) tests conducted on undisturbed soil samples. Central to its function is the transformation of load–deformation curves into quantitative soil behavior descriptors, including the compression index (Cc), recompression index (Cr), preconsolidation pressure (σ'ₚ), coefficient of consolidation (cv), and permeability (k). The workbook emphasizes best practices in data correction—such as accounting for instrument compliance, sample disturbance, and time-log corrections—and promotes consistency in identifying the Casagrande and Schmertmann graphical breakpoints for σ'ₚ determination. It also integrates modern interpretation techniques, such as log-time and square-root-of-time methods for cv calculation, and often includes worked examples, blank templates for plotting, and decision trees for classifying soil compressibility (e.g., using Skempton’s classification). Practitioners use this workbook not only for academic training but also to ensure regulatory compliance (e.g., ASTM D2435/D2435M, BS 1377-5, ISO 17892-5) and to support peer-reviewed reporting in geotechnical site investigation reports.