中文摘要：

桥上纵连板式无砟道岔采用垂向分层的拼装式结构,道岔板与砂浆层间界面是其薄弱环节.受砂浆材料性能和施工因素等影响,在温度荷载作用下道岔板与砂浆层间易产生层间离缝,从而严重降低了道岔结构的整体性.以18号单开道岔为例,分析了整体温度荷载和温度梯度荷载组合作用下离缝对桥上纵连板式无砟道岔受力和限位性能的影响.采用ANSYS有限元软件建立了桥上纵连板式无砟道岔结构计算模型,分别模拟了正常状态下和离缝区域内道岔板与砂浆层的层间界面关系,分析了不同离缝形式和离缝面积对道岔板受力和限位性能的影响.结果表明：道岔板和砂浆层层间局部离缝对道岔板的受力和变形危害不大,但会显著影响砂浆层对道岔板的限位性能;板端和板边离缝形式对道岔板受力和限位性能的影响最显著,板角离缝次之,板中离缝的影响最弱;离缝面积的大小对其有一定影响.本文结论对桥上纵连板式无砟道岔结构的整体性设计的改进具有参考意义。

英文摘要：

The longitudinally coupled ballastless welded turnout on bridges is the layered structure in vertical direction.The interface of turnout slab and mortar layer is its weak link.Influenced by mortar material properties and construction factors,there is alienation seam on interface of turn-out slab and mortar layer under temperature load,which will reduce the integrity of the structure seriously.Taking No.18 longitudinally coupled ballastless turnout on bridges for instance,the in-fluence of seam between slab layers on the mechanical behavior and limit location property of the structure is researched under the action of overall temperature load and temperature gradient to-gether.By means of finite clement analytic software ANSYS,the calculation model of the longitu-dinally coupled ballastless turnout structure on bridges is established.The interface relationships between the turnout slab and cement asphalt mortar under the normal state and layer seam aliena-tion condition are simulated,respectively.And the influence of layer seam positions and seam area on the mechanical behavior and restrict capability of the turnout slab is analyzed.Calculation re-sults show as follows：interface connection seam has little impact on the mechanical behavior and deformation of the turnout slab,however,it influences on the limit location property of turnout slab significantly.The seam at the head and at the edge of slab has the biggest influence on the turnout slab＆#39;s stress and limit location property;the seam at the corner of slab comes second;and the seam at the middle of slab has minimal impact.The conclusion has the reference significance to improve the design integrity of longitudinally coupled ballastless welded turnout on bridges.