The action between bridge and ballasted jointless turnout on bridge is reversible. To locate the force path between them,the model of a jointless turnout on a 4×32 m continuous beam were calculated and analyzed. ...The action between bridge and ballasted jointless turnout on bridge is reversible. To locate the force path between them,the model of a jointless turnout on a 4×32 m continuous beam were calculated and analyzed. Also analyzed were factors of influence,such as：temperature increment,longitudinal pier stiffness,ballast resistances,and turnout and bridge layouts.展开更多
For the longitudinally coupled baUastless turnout on Leida bridge on Wuhan-Guangzhou passenger dedicated line （PDL） in China, a turnout （cross over）-track slab-bridge deck-pier integrated finite element model was ...For the longitudinally coupled baUastless turnout on Leida bridge on Wuhan-Guangzhou passenger dedicated line （PDL） in China, a turnout （cross over）-track slab-bridge deck-pier integrated finite element model was established, in which two No. 18 jointless turnouts with movable frogs in form of crossover, longitudinally coupled ballastless track, bridges and piers were regarded as one system. Based on this model, the additional forces and displacement regularities of turnouts, track slab, bridges and piers under occasional loading were analyzed, and the effect of occasional loading position was researched. The results show that slab breaking is more influential on the longitudinal force and deformation of the whole system than rail breaking, that slab breaking on one line could deteriorate both the slab force on another line and the forces exerted on the piers and fastener components, and that a great slab force at the left end of the continuous bridge expansion joint should be particularly avoided in design.展开更多
A jointless bridge could fundamentally eliminate vulnerable deck joints, thereby meeting the need for sustainable development of bridges, especially for an expressway with highspeed traffic. In this paper, one jointle...A jointless bridge could fundamentally eliminate vulnerable deck joints, thereby meeting the need for sustainable development of bridges, especially for an expressway with highspeed traffic. In this paper, one jointless bridge(deck-extension bridge) with a small box girder in an expressway was chosen as a case study to examine the structural design,construction and field test. The field tests of the bridge indicated that the designed and constructed structures can satisfy the requirement for service performance of the deckextension bridge. Some key technologies, such as the position of longitudinal reinforcements in the superstructure-approach slab connections and the arrangement of the sliding material layers, were introduced. The longitudinal thermal movement of the superstructure in the deck-extension bridge with a small box girder could be predicted accurately by using the average temperature of the cross section of a small box girder. The finite element model, built by using the MIDAS program, was used to analyze the temperature distribution on the cross section of a small box girder, the accuracy of which could be verified by comparing with the measured values. The maximum longitudinal thermal movement of the superstructure in deck-extension bridges with a small box girder under historically extreme temperature conditions was predicted.展开更多
文摘The action between bridge and ballasted jointless turnout on bridge is reversible. To locate the force path between them,the model of a jointless turnout on a 4×32 m continuous beam were calculated and analyzed. Also analyzed were factors of influence,such as：temperature increment,longitudinal pier stiffness,ballast resistances,and turnout and bridge layouts.
文摘For the longitudinally coupled baUastless turnout on Leida bridge on Wuhan-Guangzhou passenger dedicated line （PDL） in China, a turnout （cross over）-track slab-bridge deck-pier integrated finite element model was established, in which two No. 18 jointless turnouts with movable frogs in form of crossover, longitudinally coupled ballastless track, bridges and piers were regarded as one system. Based on this model, the additional forces and displacement regularities of turnouts, track slab, bridges and piers under occasional loading were analyzed, and the effect of occasional loading position was researched. The results show that slab breaking is more influential on the longitudinal force and deformation of the whole system than rail breaking, that slab breaking on one line could deteriorate both the slab force on another line and the forces exerted on the piers and fastener components, and that a great slab force at the left end of the continuous bridge expansion joint should be particularly avoided in design.
基金supported by National Natural Science Foundation of China(grant numbers 51508103,51778148,51578161)Recruitment Program of Global Experts Foundation(grant number TM2012-27)
文摘A jointless bridge could fundamentally eliminate vulnerable deck joints, thereby meeting the need for sustainable development of bridges, especially for an expressway with highspeed traffic. In this paper, one jointless bridge(deck-extension bridge) with a small box girder in an expressway was chosen as a case study to examine the structural design,construction and field test. The field tests of the bridge indicated that the designed and constructed structures can satisfy the requirement for service performance of the deckextension bridge. Some key technologies, such as the position of longitudinal reinforcements in the superstructure-approach slab connections and the arrangement of the sliding material layers, were introduced. The longitudinal thermal movement of the superstructure in the deck-extension bridge with a small box girder could be predicted accurately by using the average temperature of the cross section of a small box girder. The finite element model, built by using the MIDAS program, was used to analyze the temperature distribution on the cross section of a small box girder, the accuracy of which could be verified by comparing with the measured values. The maximum longitudinal thermal movement of the superstructure in deck-extension bridges with a small box girder under historically extreme temperature conditions was predicted.
