Abstract：With Fourier-Bessel function expansion，the dynamic stress concentration factor of the cylindrical composite-lining cavity subjected to vertically incident plane SV waves was derived for an half elastic space with double lining and buffer layer，named as rock-buffer layer-lining. The factors affecting the dynamic stress characteristic of the lining structure such as the incident wave frequency，elastic modulus and thickness of the buffer layer were discussed. The damping mechanism of the buffer layer was studied with the solution and the numerical simulation. The results showed that the frequency of the incident SV waves played an important role in the dynamic stress concentration factor of the combined-lined cavity，and the dynamic stress concentration factor of the lining decreased effectively with the buffer layer subjected to low incident frequency waves. Because of the low shear modulus of the damping layer，the shear deformation of surrounding rock and tunnel was generated， so that the normal force on the lining decreased and the dynamic stress concentration factor of the inner lining decreased. But the tangential stresses in the wall rock and outer part of the lining increased with buffer layer. With the lower elastic modulus and lager thickness of the buffer layer，the dynamic stress concentration factor of the secondary lining decreased. The optimum elastic modulus ratio of the buffer layer to surrounding rock was proposed to below 1/10–1/20，and there is an optimal thickness of the buffer layer for one specific elastic modulus. Then the shaking table tests were accomplished based on a road tunnel，and the results showed that the dynamic internal forces of the tunnel decreased and the crack number of the lining reduced with buffer layers.
2016, Vol. 35 
