Applications of laser induced breakdown spectroscopy in geotechnical engineering: a critical review of recent developments, perspectives and challenges

Laser-induced breakdown spectroscopy (LIBS) is a remarkable elemental detection and quantification technique used in various fields, including science, medicine, engineering, and industries. This review focuses on the recent progress and challenges in applying LIBS for geotechnical engineering applications. The paper also discusses the widely employed calibration-free LIBS methods such as chemometrics, artificial neural networks (ANN), and support vector machine (SVM) for quantifying constituent elements. The various applications of LIBS in geosciences, such as in mineralogy, soil studies, rocks investigations, and fluid analysis, have also been presented. Despite the robustness of LIBS in soil studies, it is hitherto challenging to investigate some soil physical parameters. In general, chemical applications such as contamination detection and nutrients are based on detecting certain elements or ions. On the other hand, physical and mechanical applications such as soil texture and soil humification degree may require the usage of a correlation between the chemical elements and the desired parameters. This work, therefore, summarizes how LIBS works with different materials and its current uses in determining the physical or mechanical properties of soils and presents the possibilities of this technology in the field of Geotechnical Engineering.