ABSTRACT
ABSTRACT During the construction of typical shield tunnels, working shafts were always built at the two ends of the tunnels. Generally, shield tunnels have good structural performance against earthquakes, because the tunnel consists of segmental linings. However, the shaft ingate, where the tunnel initiates or ends, is prone to seismic hazard due to its sharp structural and geometric changes, and it could not be studied by any analytical methods yet. This paper shows the work of a shaking table test, targeted on the seismic behavior of the shaft ingate. The design and the results of the test are introduced. The acceleration responses of the tunnel and the maximum extensions of the circumferential joints were measured and analyzed. It could be observed from the test that the junction of the shaft ingate and the shield tunnel is particularly vulnerable to seismic impact as the consequence of discrepant acceleration responses.
