Influence of a new‐bored neighbouring cavity on the seismic response of an existing tunnel under incident P‐ and SV‐waves

Abstract

One of the important problems regarding the tunnel design in seismically active areas is the assessment of the mutual effect of two closely running tunnels. With the propagation of seismic waves, the stresses in certain sections of a tunnel, owing to the presence of an adjacent tunnel, can exceed those occurring when considering the single‐tunnel case. In the focus of this study is the hitherto unexplored elastic wave diffraction problem, which considers the influence of the presence of a new‐bored neighbouring cavity on the seismic response of an existing tunnel, under incident P‐waves/SV‐waves. The wave function expansion method, the corresponding boundary conditions along the tunnel and cavity contours, and the translational addition theorem for bi‐cylindrical wave functions are jointly employed to develop an exact mathematical solution of the given problem in the form of infinite FourierBessel series, under the plane‐strain conditions. The dynamic effects of structures are presented in the form of a newly introduced dynamic stress alteration factor as a measure of the variation of dynamic hoop stress amplitudes in the lining and the surrounding medium of an existing tunnel affected by the presence of a closely running newly‐constructed tunnel opening. The results of this study are believed to be useful for interpretation of design rules, particularly considering that seismic standards for tunnels are still in the preliminary stage, where the aspect of the minimum seismically safe distance of a newly‐constructed tunnel opening in the vicinity of an existing tunnel should be of particular concern.

Seismic Response and Damage Analysis of Shield Tunnel with Lateral Karst Cavity under Oblique SV Waves

“…The seismic response characteristics of the structure are related to the types and the incident angles of the seismic wave. Compared with P waves, the tunnel's damage caused by SV waves is more serious [23][24][25][26]. Savigamin et al [27] derived two analytical solutions to explore the structural axial direction response of the circular tunnel under the shear wave.…”

Dynamic Response of Twin Circular Unlined Tunnels Subjected to Blasting P Waves

“…Qiu et al (2022) studied the blasting dynamic behavior of deep buried tunnels and discussed their safety. Zlatanović et al (2021) and Yuan et al (2020) explored the influence of new structures on the dynamic responses of existing tunnels subjected to different incident waves. Although the study on different factors influencing dynamic response of underground tunnels subjected to incident waves has made great progress, the quantitative relationship between different factors and dynamic response of tunnels subjected to incident waves is very limited.…”