Stress Characteristics and Crack Prevention Optimization Measures of Ballastless Track with Double-block Sleeper in Tunnel
In response to the problem of frequent cracks in slab of ballastless track with double-block sleeper at the construction joint position of the tunnel inverted arch,which affects the long-term service life of the ballastless track during the construction stage,a finite element overall model of longitudinal connected type and unit type ballastless track with double-block sleeper was established.The main tensile stress of the track bed slab at the construction joint position of the inverted arch under different working conditions was analyzed,and the concrete shrinkage and the stress state of the concrete under the overall temperature load were discussed.Based on the analysis results,preventive measures for cracks in ballastless track with double-block sleeper were proposed from the perspective of structural optimization and construction.The results show that the main tensile stress of the longitudinal connected track slab at the construction joint decreases with the increase of the base stiffness,while the main tensile stress of the unit track slab decreases with the decrease of the board length.The use of reinforcement planting measures can effectively reduce the stress levels of the two types of track slab structures at construction joints,and the main tensile stress of the track slab decreases with the decrease of the spacing between reinforcement planting.After comprehensive consideration,it is recommended to adopt reinforcement planting measures in the construction joint area of the track slab in actual engineering,with two sleepers arranged at intervals between the reinforcement planting.
high speed railwayballastless track with double-block sleepernumerical simulationinverted arch construction jointcrack initiationcrack prevention
NETL
NSTL
万方数据
