Abstract：The displacement of deformation joint of utility tunnel may cause additional force of the continuous pipeline in the utility tunnel along its longitudinal direction, affecting the safety of the pipeline. In order to limit the displacement of the deformation joint of the utility tunnel, shear anchor bars are used in the deformation joints. To study the mechanical properties and seismic ductility of the shear anchor bars of the deformation joints in the utility tunnel, the mechanical properties and seismic ductility of the deformation joints of the utility tunnel connected by shear anchor bars are systematically studied based on the cyclic loading tests of four scaled models of the entire structure, with the utility tunnel in Tianfu new area of Chengdu taken as an example and the layout, the number and the anchorage length of anchor bars taken as the input parameters. The failure mode, failure phenomenon, force-displacement curve and ductility coefficient of the specimens are then obtained. The experimental results showed that the shear anchor bars in the deformation joints of the utility tunnel had good ductility and seismic performance; under the test conditions, the shear anchor bar did not fail along its anchorage length; the failure of the specimen mainly appeared to be the breakage of the shear anchor bars, accompanied by the large-scale cracking of the concrete; the ultimate bearing capacity of the specimen was directly proportional to the number of shear anchor bars; comparing the shear anchor bars arranged only on the side walls with the ones arranged on all sides, no obvious change in the ultimate bearing capacity could be observed, but the ultimate displacement was relatively larger and the ductility was poorer.
