pyelogp 0.1.1

A lightweight Python library to estimate preconsolidation pressure using volumetric strain energy method with knee detection in the e-log(P) space.

PyelogP

"Py e-log(P)" is a lightweight Python library for estimating the preconsolidation pressure (P'c) of oedometer test data using the strain-energy method with knee-point detection and thresholding in the e-log(P) space.

Features

• Manual data input or import from a .csv file.
• Automatic removal of unload–reload cycles from input data.
• (Beta) Threshold-based fitting range selection for S-shaped curves.

Installation

pip install pyelogp

Clone from GitHub

git clone https://github.com/liangchow/pyelogp.git
cd pyelogp
python -m venv .venv           # Recommended to use venv
source .venv/bin/activate      # Windows: .venv\Scripts\activate
pip install -e .

Quick start

See run.py for a full example, including loading data from a CSV file via Data.from_csv.

from pyelogp import Data

# Louiseville clay
pressure = [59, 90, 120, 150, 165, 172, 184, 222, 300, 400]
void_ratio = [2.115, 2.113, 2.098, 2.083, 2.055, 2, 1.8, 1.5, 1.3, 1.193]
e0 = 1.21 (Optional)

d = Data(pressure=pressure, void_ratio=void_ratio, e0=e0)

# Run analysis
result = d.find_pc()
print(f"Pc  = {result.pc:.1f}")
print(f"e @ Pc = {result.e_pc:.4f}")
print(f"R²(seg1) = {result.r2_seg1:.4f}")
print(f"R²(seg2) = {result.r2_seg2:.4f}")

# Return
Preconsolidation pressure (Pc): 164.49
Void ratio at pc (e_pc): 2.0573
R² segment 1: 0.893768
R² segment 2: 0.96937

Contributing

Contributions are welcome, please refer to CONTRIBUTING to learn more about how to contribute.

References

Becker, D. E., Crooks, J. H. A., Been, K., & Jefferies, M. G. (1987). Work as a Criterion for Determining in situ and Yield Stresses in Clays. Canadian Geotechnical Journal, 24(4), 549–564.

Bonaparte, R. and Mitchell, J.K. (1979). The Properties of San Francisco Bay Mud at Hamilton Air Force Base, California. Geotechnical Engineering Report, University of California, Berkeley, April 1979.

Satopa, V., Albrecht, J., Irwin, D., and Raghavan, B. (2011). Finding a 'Kneedle' in a Haystack: Detecting Knee Points in System Behavior. 31st International Conference on Distributed Computing Systems Workshops, 166-171.

Terzaghi, K., Peck, R.B., & Mesri, G. (1996). Soil Mechanics in Engineering Practice (3rd ed.). John Wiley & Sons, Inc.