Laser-induced breakdown spectroscopy (LIBS) is a remarkable
elemental
identification and quantification technique used in multiple sectors,
including science, engineering, and medicine. Machine learning techniques
have recently sparked widespread interest in the development of calibration-free
LIBS due to their ability to generate a defined pattern for complex
systems. In geotechnical engineering, understanding soil mechanics
in relation to the applications is of paramount importance. The knowledge
of soil unconfined compressive strength (UCS) enables engineers to
identify the behaviors of a particular soil and propose effective
solutions to given geotechnical problems. However, the experimental
techniques involved in the measurements of soil UCS are incredibly
expensive and time-consuming. In this work, we develop a pioneering
technique to estimate the soil unconfined compressive strength using
artificial intelligent methods based on the spectra obtained from
the LIBS system. Decision tree regression (DTR) and support vector
regression learners were initially employed, and consequently, the
adaptive boosting method was applied to improve the performance of
the two single learners. The prediction power of the established models
was determined using the standard performance evaluation metrics such
as the root-mean-square error, CC between the predicted and actual
soil UCS values, mean absolute error, and R
2 score. Our results revealed that the boosted DTR exhibited the highest
coefficient of correlation of 99.52% and an R
2 value of 99.03% during the testing phase. To validate the
models, the UCS values of soils stabilized with lime and cement were
predicted with an optimum degree of accuracy, confirming the models’
suitability and generalization strength for soil UCS investigations.