Experimental Study on Flexural Performances of Transverse Connections Between Grooved Prefabricated Concrete Linings of Tunnels

Against the background of prefabricated concrete linings of tunnels in a tram project, to study the influence of interfacial treatment ways on flexural performances of transverse connections of the tunnel, four-point loading flexural tests were conducted on three specimens treated with epoxy resin, non-shrinkage mortar and without any treatment respectively. The experimental results indicated that the opening at connections varied linearly along height of specimens, whether the interfaces be treated has little effect on the ultimate bearing capacity of specimens. In the standard combination, basic combination, frequent seismic combination, fortification seismic combination and rare seismic combination, the transverse connections of tunnels did not reach the cracking moment, and still had a large safety margin. The ductility of the specimen without any treatment was best. But after unloading, the residual deformation of the specimen treated with non-shrinkage mortar was smallest, and the restorability was best. The flexural stiffness of connections simulated by the three line-segment model could better fit the moment-rotation curve, but it could not reflect the nonlinear characteristics at the deformation development stage of specimens, the theoretical moment-angle curves were basically consistent with the experimental moment-rotation curves, and the flexural stiffness of specimens filled with non-shrinkage mortar was best. Comprehensively considering all factors, it was a better choice not to treat on interfaces of connections in practical engineering.