钢桁梁明桥面合成轨枕结构初步设计及其受力分析

Structure Design and Stress Analysis of Composite Sleeper on Steel Truss Bridge Deck

合成轨枕是一种以玻璃长纤维和硬质聚氨酯树脂为主要成分,通过成型板压缩粘结制造而成的轨枕。通过对明桥面上铺设合成轨枕的结构进行设计与计算,确定了明桥面上合成轨枕的结构形式。基于有限单元法建立由5根轨枕组成的轨排模型,对该模型进行受力分析,并研究合成轨枕厚度和宽度变化时其位移和应力的变化规律。研究结果表明：随着合成轨枕厚度的增加,轨下轨枕垂向位移值将趋于定值；随着合成轨枕宽度的增加,轨下轨枕垂向位移值也将趋于定值。合成轨枕的尺寸对轨枕压应力的影响较大,对轨枕拉应力的影响较小。综合考虑合成轨枕的承载力要求、扣件安装需要的合理尺寸、轨枕安装需要的安装空间、现场施工条件对尺寸的要求及经济性等因素,确定了合成轨枕的合理尺寸为：长度3000 mm,宽度取值范围为260~300 mm,厚度取值范围为220~280 mm。

The synthesis sleeper is a kind of sleeper which is mainly consisted of long glass fiber and rigid polyurethane resin and manufactured by compressing with molding plate bonding. With design and calculation of the composite sleeper on the bridge deck, the structural form is determined. A track row model with 5 sleepers is established based on the finite element software ANSYS to analyze the stress of the model and study the displacement and change with the change of the composite sleeper height and width. The results show that with the increase of thickness of synthetic sleeper, the vertical displacement of the sleeper under rail tends to become constant; with the increase of the synthetic sleeper width, the vertical displacement under rail also tends to become constant. The size of the synthesis sleeper has greater effect on the sleeper compressive stress than on the tensile stress. With the comprehensive consideration of the requirements for bearing capacity of the composite sleeper, the reasonable installation dimensions of the fastener, the space for installation of the sleeper, the site construction conditions, the economy and so on;the reasonable size of the sleeper is determined to be 3 000 mm long, 260~300 mm wide and 220~280 mm thick.