A state-of-the-art review on 1-g experimental investigations on tunnels subjected to dynamic loading conditions

Underground structures constitute a vital component in infrastructure development. When subjected to dynamic events, these underground structures will result in catastrophic failures. Hence proper understanding of soil-underground structure interaction is essential when designing in seismic-prone areas. Though analytical models estimate the performance of underground structures under dynamic loading conditions, detailed experimental studies provide more insights into the parameters influencing the underground structure's performance during dynamic conditions. Due to the limitations in model development, time, and cost, 1-g shaking table experiments were preferred by most of the researchers compared to centrifuge and field scale experiments. This paper presents a detailed literature review of experimental studies on tunnel models in 1-g shaking table experiments and critical observations on tunnel-soil interaction under dynamic loading conditions. Discussions on scaling laws, instrumentation scheme, material selection, and other influencing parameters involved in soil tunnel interaction studies in 1-g shaking table testing conditions are presented. Although the 1-g experimental testing conditions have limitations in simulating equivalent ground and testing conditions as compared to centrifuge studies, this paper highlights the possible steps to simulate the tunnel model interaction studies in a better way to minimize the limitations for upcoming future research works.