Multi-attribute seismic data spectrum analysis of tunnel orthogonal underpass landslide shaking table test

摘要

To explore the spatial deformation characteristics and dynamic response law of the tunnel's orthogonal un-derpass landslide under potential seismic action, we carried out the shaking table test for the first time. We measured and obtained the seismic data with various attributes, such as the characteristic image of different probability horizontal seismic action, acceleration, dynamic soil pressure and dynamic strain. Based on the time-domain analysis of multi-attribute data such as deformation characteristics and acceleration, we revealed the spatial dynamic response characteristics of the lining structure at different positions in the annular particle. By Wavelet Transform, we obtained the time-frequency variation relationship between the multi-attribute data. In addition, we discussed in detail the relationship between the frequency and the specific period of acceleration, dynamic soil pressure and dynamic strain at different probabilities of horizontal vibration stages. We then proposed the damage level correlation quantitatively characterized by the spectrum characteristics of multi-attribute data through Fast Fourier Transform and statistical probability scatter-matrix operations. The sensi-tivity difference of multi-attribute seismic data was significant. The time-history effect of dynamic soil pressure was the most sensitive and the time-history effect of dynamic strain had obvious hysteresis compared with ac-celeration. In the frequency domain of multi-attribute seismic data signals, the predominant frequencies were mainly concentrated in 1-10 Hz, and their dominant frequencies were significantly different. The singular boundary between low-frequency and high-frequency was 10 Hz, and the structures with frequencies between 15 and 20 Hz were relatively safe. Multi-attribute data response variables were positively correlated, acceleration was highly correlated with dynamic soil pressure response, while acceleration was weakly correlated with dy-namic strain response, showing a significant correlation. Due to the spatial location of the tunnel's orthogonal underpass landslide, and the effect of seismic wave amplification and bias effect of mountain tunnel, the lining was damaged in a regional difference, and the inverted arch uplift cracked into a weak area. The research results can provide a theoretical reference for the failure model prediction and engineering safety evaluation of the tunnel's orthogonal underpass landslide in high intensity earthquake area.