PyelogP: Automated Energy-Based Determination of Preconsolidation Pressure in Clay Deposits
Abstract
Estimating the preconsolidation pressure (σ'p) from one-dimensional consolidation (oedometer) tests is critical in geotechnical engineering for settlement analysis. Traditional graphical methods, such as the Casagrande procedure, may introduce uncertainties, particularly when interpreting rounded e-log(P) curves typical of disturbed specimens of soft clays and silt deposits. This paper introduces PyelogP, an open-source Python library designed to calculate σ'p using the strain-energy method proposed by Becker et al. (1987) as an automated and reproducible alternative. The algorithm combines natural cubic spline interpolation, knee-point detection via the Kneedle algorithm, and split-point linear regression within the work-pressure space. Physically informed thresholds, including overconsolidation ratio limits and second-derivative maxima (d2 e/d(log σ')2), are incorporated to establish pre-yield and post-yield fitting boundaries. The performance of PyelogP is evaluated against a suite of 22 experimental consolidation datasets covering various clay deposits, including Saint-Alban clay and San Francisco Old Bay Clay. The results demonstrate strong agreement with the published values (R2 = 0.912, RMSE = 0.374, MBE = -0.080), while the O(N2) algorithm requires only a few milliseconds per curve for typical oedometer datasets and less than 150 milliseconds for the largest datasets.
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BibTeX
@misc{chow2026pyelogp,
title = {{PyelogP: Automated Energy-Based Determination of Preconsolidation Pressure in Clay Deposits}},
author = {Liang Chern Chow and Thierno Kane},
howpublished = {arXiv},
year = {2026},
month = sep,
doi = {10.48550/arxiv.2609.09430},
eprint = {2609.09430},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2609.09430},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - PyelogP: Automated Energy-Based Determination of Preconsolidation Pressure in Clay Deposits
AU - Liang Chern Chow
AU - Thierno Kane
PY - 2026
DA - 2026/09/08
PB - arXiv
DO - 10.48550/arxiv.2609.09430
UR - https://arxiv.org/abs/2609.09430
AB - Estimating the preconsolidation pressure (σ'_p) from one-dimensional consolidation (oedometer) tests is critical in geotechnical engineering for settlement analysis. Traditional graphical methods, such as the Casagrande procedure, may introduce uncertainties, particularly when interpreting rounded e-log(P) curves typical of disturbed specimens of soft clays and silt deposits. This paper introduces PyelogP, an open-source Python library designed to calculate σ'_p using the strain-energy method proposed by Becker et al. (1987) as an automated and reproducible alternative. The algorithm combines natural cubic spline interpolation, knee-point detection via the Kneedle algorithm, and split-point linear regression within the work-pressure space. Physically informed thresholds, including overconsolidation ratio limits and second-derivative maxima (d^2 e/d(log σ')^2), are incorporated to establish pre-yield and post-yield fitting boundaries. The performance of PyelogP is evaluated against a suite of 22 experimental consolidation datasets covering various clay deposits, including Saint-Alban clay and San Francisco Old Bay Clay. The results demonstrate strong agreement with the published values (R^2 = 0.912, RMSE = 0.374, MBE = -0.080), while the O(N^2) algorithm requires only a few milliseconds per curve for typical oedometer datasets and less than 150 milliseconds for the largest datasets.
ER -