无砟轨道路桥连接处楔形体过渡方式优化设计

Optimization Design of Wedge Structure of Transition Section at the Junction between Subgrade and Bridge with Ballastless Track

针对无砟轨道路桥过渡段差异沉降楔形体处治方式,综合考虑轨道整体刚度和不均匀沉降的发展两大指标,建立相应的有限元分析模型,对不同的楔形体纵面坡度大小及设置方向进行分析比选,并对所选过渡段设置形式进行地基沉降适应性仿真分析。结果表明:采用正梯形楔形体比倒梯形楔形体更有利于轨道刚度过渡;建议采用坡度为1∶1.5的正梯形楔形体过渡方式,可大大减少换填量(相对1∶2方式),且较好地协调好沉降差(相对1∶1方式);当地基为均匀沉降时,楔形体换填无法从根本上消化地基沉降,在实际工程中,应注意配合其他措施综合治理。

Focusing on the wedge structure at the transition section in relation to settlement difference between the subgrade and the bridge with ballastless track, and comprehensively considering the two indexes including the whole track rigidity and the uneven settlement development, the thesis established the relevant finite element model. Furthermore, the different sizes and directions of profile grade of the wedge structure were analyzed and compared. And then by means of the transition section modes selected, the simulation analysis of the subgrade settlement adaptability was carried out. The results show that： the trapezoidal wedge structure is more conducive to the track rigidity transition than the inverted trapezoidal wedge structure. And it is suggested that the trapezoidal wedge structure with i ： 1.5 slope should be taken as the transition mode, because it can greatly reduce the amount of earth replacement （ compared to 1 ： 2 mode）, and can well coordinate the settlement difference （ compared to 1 ： 1 mode）. However, for the case of subsgrade uniform settlement, it is impossible to solve the problem of subgrade settlement merely by the wedge structure replacement, therefore, other relevant treatment measures should be employed so as to solve the problem by cooperating with each other and by comprehensive treatment.