This book offers a multidisciplinary collection of cutting-edge studies addressing challenges in underground construction, tunneling, and rock engineering. Combining theoretical models, laboratory experiments, and field applications, it highlights advances in thermo-hydro-mechanical behavior of rocks, fluid&structure interactions, and excavation performance under complex geological conditions. Contributions showcase innovative methods such as DEM, thermal&mechanical coupling, AI-assisted blast design, and advanced monitoring technologies. Case studies of seismically active and high-pressure groundwater regions showcase real-world engineering solutions. Topics span poromechanics, fracture permeability, slope stability, mining excavation, and novel experimental techniques. By integrating modeling, field validation, and technological innovation, the book serves as a key reference for engineers, researchers, and decision-makers seeking resilient and sustainable underground infrastructure.