Advanced Automated Consolidometer for Enhanced Soil Consolidation Testing

Abstract Geotechnical analysis of clay soils traditionally relies on incremental load consolidation tests to determine key parameters for estimating soil settlement, which often require extensive testing times of up to 288 hours. This study presents an advanced automated consolidometer system aimed at enhancing both the accuracy and efficiency of soil consolidation testing. The system integrates microcontroller technology and sensors for real-time measurements of axial stress, displacement, and pore water pressure. Key components include a load cell for axial pressure measurement, a dial indicator for monitoring displacement, and a pressure transmitter for pore water pressure assessment, all managed by a stepper motor controlled through an Arduino microcontroller. Data acquisition and processing are facilitated using LabVIEW, enabling seamless and efficient data management. The system utilizes On-Off (Bang-Bang) control logic for precise load application during soil consolidation tests. This straightforward control strategy ensures consistent performance by switching the motor on and off as needed, maintaining loads within specified thresholds. Additionally, Linear Quadratic Regulator (LQR) analysis is employed to comprehensively evaluate the system’s stability, transient response, and control dynamics, offering a theoretical framework for optimal control performance. The modified CRS (Constant Rate of Strain) method integrated into the system reduces testing time significantly to just 8.5 hours, achieving a 97% reduction compared to the traditional incremental load method, while maintaining high accuracy in test results. By leveraging both practical and analytical control strategies, the automated consolidometer achieves remarkable efficiency and precision, making it highly applicable for modern geotechnical engineering needs.