Shaking table test of the dynamic response of a tunnel across a main sliding surface

Abstract

A shaking table test was conducted to study the dynamic response of a tunnel across a main-sliding surface under seismic action for the first time, and acceleration and dynamic strain data were obtained. A strain-time domain analysis method was implemented to reveal the distribution of the strain field strength factors in the tunnel lining. The plastic effect coefficient (PEC) was proposed to describe the extent of plastic deformation of the tunnel lining, and the applicability of the seismic cumulative failure effect (SCFE) in the stress strength analysis was assessed. The acceleration field of the tunnel lining was also analyzed in the time–frequency domain. The magnification of the Arias intensity (MIa) was applied to characterize the whole-local deformation damage of the tunnel lining, which was considered from the aspects of deformation characteristics, frequency domain, and energy. The results suggest that the residual strain (RS) and PEC are more sufficient to describe the plastic deformation characteristics of the tunnel lining than the increment of the peak dynamic strain (ΔPDS). In addition, PEC has a more definite physical meaning than RS; thus, it is capable of defining the SCFE of the tunnel lining, which describes the stages of deformation effects, including the elastic deformation effect stage (<0.15 g), elastic–plastic deformation effect stage (0.15–0.3 g), and plastic deformation effect stage (0.3–0.6 g). In addition, according to MIa energy and different frequency-domain incremental displacement analyses, the low-frequency component of seismic waves results in global deformation of the lining section, whereas the high-frequency component causes vault and arch waist-H local deformation. The results of MIa and PEC values can provide a scientific basis for identifying the seismic failure state of the tunnel lining and appropriate seismic reinforcement.