Research on tunnel damage process based on acoustic emission technology

For a long time, it is generally believed that the tunnel has excellent seismic performance and can resist earthquake damage, so it will not be damaged. However, according to the survey of tunnels after the Wenchuan earthquake in China, 110 tunnels were damaged to varying degrees. In this paper, a series of shaking table tests were carried out on the proportional tunnel model under seismic excitation. Acoustic emission technology is combined with seismic excitation to identify and describe the damage of tunnel lining. The tunnel lining strain and acoustic emission signals are collected in the test. In addition, this paper also introduces the use of acoustic emission technology to describe the damage of tunnel lining. Taking the crown as an example, through the correlation analysis of amplitude, counts and energy, it is preliminarily judged that the crown is damaged under working conditions 7 and 8; Then combined with strain analysis, it is proved that the correlation analysis is reasonable. Finally, the rationality of correlation analysis is further explained by the changes of counts, energy, and its cumulative parameters with time. At the same time, the damage process of tunnel lining under seismic excitation is described by defining damage variables, which can be divided into three stages: initial compression elastic stage, yield failure stage and residual stage.