Shaking table test and numerical simulation on seismic performance of prefabricated corrugated steel utility tunnels on liquefiable ground

The seismic failure mechanism of a shallow-buried prefabricated corrugated steel utility tunnel on the liquefiable ground was investigated by the shaking table test and numerical simulation. Firstly, A scaled model of prefabricated corrugated steel utility tunnel, inside pipelines, and three kinds of brackets were designed and fabricated. The model system was then excited by two seismic ground motions on a shaking table. Various dynamic responses of the model system were measured and the interface slip of tunnel and surrounding soil was also tested by a self-designed transducer. The experimental results demonstrated that the near-tunnel soil was more likely to liquefy than the far-field soil, and the liquefied soil had a remarkable damping effect. The bottom bracket was more vulnerable to be affected by excitations with high-frequency than the suspending and standing bracket. Both the utility tunnel and the suspending bracket yielded under the mainshock, but only slight deformations were observed with the model. Finally, the tunnel-ground system was simulated numerically using the FLAC 3D program. The comparison of experimental records with simulated results was carried out for validation of research outputs. The results provide valuable insight into the seismic performance of shallow-buried underground structures and the safe design of prefabricated corrugated steel utility tunnels.

Automated summary

The seismic failure mechanism of a shallow-buried prefabricated corrugated steel utility tunnel on liquefiable ground was investigated through shaking table tests and numerical simulations. Experimental results showed that soil near the tunnel was more likely to liquefy, with liquefied soil exhibiting remarkable damping effects. The bottom bracket was more susceptible to high-frequency excitations.