Using the Fourier-Bessel series expansion method,the dynamic stress concentration factors of deeply-buried circular composite-lined cavities subjected to plane P-waves were studied,and a dynamic stress concentration factor series solution for the cavities was derived.By combination with an actual pipe tunnel project in the IX seismic intensity zone,the influence of different combinations of lining stiffness and thickness on the factor was analyzed.This analysis shows that the dynamic stress concentration factor of the second lining decreased after installation of a grouting reinforcement zone and buffer layers.As the elastic modulus and thickness of the grouting zone increased,the factor of the second lining reduced and the optimal thickness of the grouting zone was equal to the clearance radius of the cavity.The dynamic stress concentration factor of the second lining decreased with a lower elastic modulus and larger damping layer thickness.The elastic modulus of the buffer layers was estimated to be below 1/20 of that of the surrounding rock,and the optimal thickness of the damping layers estimated at 1/50 of the cavity clearance radius.Finally,this new damping structure of "surrounding rock-grouting zone-buffer layers-lining" is proposed for shock absorption of an actual pipeline tunnel.The results show that this new structure exhibits the best damping effect when compared with other measures.