PRELIMINARY ANALYSIS AND RESEARCH ON UPWARP AND SEPERATION BETWEEN TRACK SLAB AND SUPPORT LAYER IN PASSENGER DEDICATED LINE

摘要

CRTS Ⅰ bi-block ballastless track and CRTS Ⅱ bi-block ballastless track are widely used in passenger dedicated lines,after six months to one year's operation,separation between track slab and support layer appeared.This paper focus on different design and construction conditions of the lines mentioned above,and fimite element models for the lines are built respectively.Then reasons for the separation are deeply investigated from both design and construction aspects based on field research data.Conclusions can be drawn from calculation results: To CRTS Ⅰ bi-block ballastless track,position limit effect of the end girder could not be well guaranteed.Large upwarp appeared at end girder,and the contact surface between track slab and support layer could easily be destroyed due to the effect of shear force.Therefore,the number of end girders should be redesigned to guarantee its position limit ability.To CRTS Ⅱ bi-block ballastless track,small upwarp happened in the post-pouring area because of the different construction temperature between the two sides of track slab,but the deviation was not big enough to cause separation.Furthermore,the inadequate construction strength of the contact surface between track slab and support layer and a lack of anti-shear bolt should be responsible for the separation.