Abstract: As China's economy rapidly develops, tunnel engineering construction increasingly faces complex geological environments, such as deep burial depth, high geostress, high geo-temperature, and high osmotic pressure. Consequently, investigating the mechanisms and safety prevention and control of water inrush in tunnels under these complex environments through physical model tests has become a significant topic in rock mechanics research. Based on recent research on scaling physical model tests for water inrush in tunnels both in China and abroad, we systematically review the similarity theory of fluid-solid coupling, the development of similar materials, and osmotic pressure loading methods. Furthermore, we explore potential directions for future research. After consulting various literature sources and examining typical water inrush cases, we summarize the similarity criteria for fluid-solid coupling and high geostress, the selection schemes and proportions of similar materials, and water pressure loading schemes for tests. We also suggest that future research may focus on two aspects: 1) study of similarity criteria for physical model tests in consideration of temperature fields, and 2) study of the gradual transition process between water inrush and mud inrush.

Key words: water inrush disaster, scaled physical model test, similarity theory of fluid-solid coupling, similar material, disaster-inducing factors, disaster-causing mechanism