Dynamic centrifuge tests on seismic response of tunnels in dense soil

Centrifuge tests are employed to study the dynamic response of tunnels in dense soil. Three sets of earthquake input motions with different intensities are applied. Meanwhile, a laminar box is used to consider different boundary (flexible and rigid) effects during earthquakes. The earthquake response of free field is also simulated. The responses of ground and tunnel are observed and presented. The results indicate that dynamic responses of tunnels are significantly different from those under the static condition, and that the performance of ground and tunnel depends on the intensities of the excitation motions and the physical boundaries of centrifuge model distinctively. The ground responses are different under free field and non-free field conditions, due to the existence of tunnels affecting the ground responses to some extent.