With the accelerated development of urban underground resources and the massive construction of traffic engineering over the world, more traffic tunnels and underground engineering have been built with the characteristic of large, buried depth, high stress, high water pressure, and complex geological structures such as fault fracture zones, water inrush areas, weak rock mass status, etc.

Facing these challenges, many scholars have conducted a considerable amount of research on reducing economic losses, injuries, and deaths and have obtained abundant and beneficial research results. There are many methods to study complex geological hazards. For example, a laboratory model test is an effective method used to study the evolution law of tunnel water inrush. Numerical modeling approaches such as discrete element models, finite element models, finite difference element models are used to simulate the evolution of the internal structure of fault zones, particle migration with water flow, and the stability of tunnel-surrounding rock, etc. Furthermore, due to the complexity in this research area, some uncertainty and fuzzy approaches such as set pair analysis, fuzzy mathematics, artificial neural network have been proposed and utilized to evaluate the risk of water inrush, karst tunnel stability in underground conditions.

This Special Issue aims to bring together original research and review articles to show the new advances and new insights of investigating geological hazards of tunnel and underground engineering. Laboratory model tests, field investigations, theory analysis, numerical simulations, and big data-driven approaches are welcome.

Potential topics include but are not limited to the following:

• Water inrush testing
• Stability control of weak rock mass
• Numerical modeling of geological hazards
• Big data-driven hazards assessment
• Model test of geological hazards
• Field cases of controlling hazards
• Theoretical analyzing of nature hazards
• Safety control of tunnel and underground engineering
• Monitoring of geological hazards
• New materials and techniques for reducing hazards