Design and Evaluation of a Portable Bedrock Hardness Testing Device

Thesis Abstract

The assessment of bedrock hardness is a critical component in geological investigations, particularly for infrastructure development, mineral exploration, and geotechnical engineering, yet existing traditional testing methods are often laboratory-bound, time-consuming, and require cumbersome equipment unsuitable for field conditions. This study aims to design, develop, and evaluate a portable bedrock hardness testing device that offers rapid, reliable, and accurate in-situ measurements. The specific objectives include (1) designing a prototype of the device based on principles of indentation hardness testing, (2) integrating sensor technologies such as strain gauges and depth sensors for real-time data collection, (3) developing calibration protocols to correlate device readings with standard hardness values, and (4) evaluating the device’s performance through field testing across diverse geological settings. The research employs a mixed-methods approach, combining engineering design, experimental testing, and statistical analysis. The study population consists of twenty geological sites with varying bedrock compositions, selected through stratified random sampling to ensure representative geological variability. A sample size of fifty measurement points per site was determined based on power analysis to ensure statistical significance. Data collection involved deploying the prototype device at each site, recording hardness values, and comparing them with results obtained through traditional Schmidt hammer and rebound hardness methods. To validate the device’s accuracy and precision, the collected data were analyzed using regression analysis to establish correlation coefficients between the new device and standard methods, and ANOVA tests to examine differences across geological settings. Calibration models were developed through multiple linear regression to adjust for site-specific variables. Expected findings indicate that the portable device will demonstrate a high correlation (above 0.85) with standard hardness testing techniques, with an acceptable margin of error within ±5%. The device is anticipated to be user-friendly, producing consistent results within a 10-minute measurement window, and operational across different bedrock types such as granite, basalt, and limestone. The analysis will reveal insights into the influence of geological variability on measurement accuracy, contributing to the refinement of calibration procedures. This study significantly advances the field of field-based geological assessment by providing a reliable, easy-to-use instrument that enhances the efficiency of bedrock hardness evaluation. It contributes to knowledge by establishing a novel application of sensor technology combined with portable engineering design for geotechnical purposes, filling the gap in rapid in-situ hardness measurement tools. Moreover, the calibration models and performance evaluation protocols developed can serve as standards for future portable hardness testing devices. The main conclusion underscores that the prototype meets the criteria for field application, offering a practical alternative to conventional laboratory methods. Recommendations include further refinement of sensor integration to improve accuracy in highly heterogeneous terrains, standardization of calibration procedures across different geological domains, and the development of digital data logging systems for long-term monitoring. Future research should explore the device’s applicability to other rock properties, such as porosity and fracture toughness, and investigate its integration with GIS platforms for spatial analysis. This innovation holds promise for improving geological hazard assessment, resource exploration, and construction site evaluation, thereby contributing valuable tools for geologists, civil engineers, and environmental scientists engaged in field investigations.