Experimental study on interlaminar displacement of CRTSⅡ ballastless track on bridge under temperature load

To study the distribution characteristics of interstory displacement of CRTS type Ⅱ slab ballastless track structure on simply supported beam bridge of high speed railway under temperature load, the temperature test was conducted on a 1/4 scaled specimen of ballastless frack-bridge structural system. In this experiment, far infrared heating lamp combined with temperature control switch and temperature sensors was used to simulate the increase and decrease of temperature. The distribution of displacement between ballastless track layers in the measured temperature mode was analyzed. The results show that, the longitudinal relative displacement between track slab, CA mortar and track bed shows a nonlinear trend. The longitudinal zero displacement between the track slab and the track bed, and that between the track bed and the beam are located at the L/8 section and the 3L/8 section(L is span), respectively. With the increase of temperature, the vertical relative displacement between the track slab and the track bed increases, and the vertical relative displacement between the track bed and the beam increases, and the vertical relative displacement displays the peak displacement on the L/4 section. Along the longitudinal direction of the bridge, the beam body gradually reaches the arch with the increase of temperature, and the displacement of the upper arch decreases with the decrease of temperature. © 2020, Central South University Press. All right reserved.