Shaking Table Experimental Investigations On Seismic Performance Of The Prefabricated Corrugated Steel Utility Tunnels

The prefabricated corrugated steel utility tunnel is a large-section shallow-buried thin-walled steel underground structure that can accommodate a variety of municipal pipelines.As a lifeline engineering structure,research on the seismic performance of the utility tunnel is very important.In this paper,two shaking table tests of the utility tunnel considering the structural from,soil-structure interaction and different kinds of pipelines and brackets in the normal site and liquefiable ground have been conducted.Firstly,the shaking table experimental results of the utility tunnel in the normal site illustrated that: the utility tunnel has significantly influence on the distribution of the soil pressure and acceleration response of the ground and there exist obvious interaction between the soil and structure.Both the utility tunnel and brackets are not yield under strong ground motions,the maximum deformation of the utility tunnel in cross section was 1.028 mm.Furthermore,the acceleration responses between suspending and standing brackets are almost as same as each other.However,the maximum strain of suspending bracket was larger than that of standing bracket.Then,the shaking table experimental results of the utility tunnel on the liquefiable ground illustrated that: comparing with the dynamic response of the utility tunnel in the normal site,on the liquefiable ground,the acceleration responses were decreased,meanwhile,the displacement responses were increased.The soil near the utility tunnel is more susceptible to liquefaction,and the liquefied soil loses its load-bearing and restraining effect on the structure.In addition to the structure uplifting,there also exist significantly relative slip between the utility tunnel and surrounding soil.Both the utility tunnel and the brackets are yield and the model structure is marginally deformed after the test.Finally,based on the experimental results and analysis,this paper proposes the key parameters that affect the dynamic response of the utility tunnel,the main damage forms of the utility tunnel at different kinds of sites,and some suggestions for the selection of the brackets inside the utility tunnel.