Seismic Damage Prediction Method for Lining Structures Based on the SEDR Principle

The safety and stability of lining structures are core concerns of tunnel and underground engineering. It is crucial to determine whether a lining structure would crack and which direction the crack would expand with seismic excitation. In previous literature, the principle based on stress and strain has been widely used to predict the seismic damage of lining structures, whereas it cannot specify the cracking modes. Taking account of that deficiency, this paper introduces the strain energy density ratio (SEDR) principle and proposes a seismic damage prediction method for lining structures, which can precisely predict the crack positions and expansion directions. Moreover, numerical simulations of the typical seismic damage sections of two tunnels in the Great Wenchuan Earthquake and a calculating example of the theoretical equations are conducted to verify the proposed method. In summary, the numerical simulation results show that the arch springing cracks first, and the invert cracks next; then the cracks expand to the spandrel, and finally, they form oblique cracks, annular cracks, and longitudinal cracks, whose positions and patterns are in accordance with the field investigation results. In terms of the calculating example results, the obtained two-fold SEDR and cracking angle θ are 1.87 and −6.28°, respectively, which are consistent with the numerical simulation results. Therefore, one can see that the proposed seismic damage prediction method based on the SEDR principle is quite accurate. This method can be used to predict the seismic damage of lining structures and provide a reference for the research of the damage mechanism of tunnels.