Abstract
When designing an earthquake-proof of shield tunnels, it is necessary to take into due consideration the axial force which arises from phase differences in seismic wave transmission in the axial direction. The important point of the analysis is whether the evaluation of the axial tensile stiffness of the tunnel is valid.
In order to investigate the axial stiffness of shield tunnels, tensile loading tests were conducted using a specimen of actual size with primary and secondary linings, which corresponds to a shield tunnel of about 14m O. D..
The results clarified the relationship for the entire lining strain-stiffness, and information was obtained concerning the behavior of lining components, such as cracks in the secondary lining and bond failure of reinforcing bars. Further more, in order to characterize the behavior of long undersea tunnels during earthquakes, seismic response was calculated from the strain-stiffness relationship of the lining obtained by these tests.
