基于极限状态法的宽轨距CRTSⅢ型板式无砟轨道配筋研究

The reinforcement design of CRTS Ⅲ slab ballastless track with track gauge widening which was based on limi-state method

针对CRTSⅢ型板无砟轨道适应性研究,建立宽轨距CRTSⅢ型板式无砟轨道的板壳模型,在路基和桥梁上,按不同设计荷载(列车竖向荷载、横向荷载、温度梯度和基础不均匀沉降荷载)作用,分别将轨道板和自密实混凝土在黏结性较强时折合为等效单层复合板结构和粘结性弱时的双层结构,采用极限状态法,按基本组合和偶然组合对宽轨距CRTSⅢ型轨道板进行配筋计算和设计,对轨道板中钢筋混凝土应力、配筋率、受压区高度、裂缝宽度和承载能力进行验算,并对轨道板在运输、吊装、施工和维修中可能出现的临时荷载进行强度检算。检算结果符合设计要求,为宽轨距CRTSⅢ型板无砟轨道适应性提供技术理论支撑。

For the study on the adaptability of CRTS Ⅲ slab ballastless track, the shell model was established tosimulate CRTS m slab ballastless track with track gauge widening in this paper. When the track slab and the self-compacting concrete have strong bond, it was equivalent to the single-layer composite slab. Otherwise, it wasequivalent to a double composited slab. The limit state method was adopted to the reinforcement design of thetrack under different loads （Vertical load of train, lateral load, temperature gradient and uneven settlement offoundation） for the first time on the roadbed and bridge. According to the basic combination and accidental com-bination of load, the most unfavorable internal force of the track slab was calculated. The stress of reinforced con-crete, the ratio of reinforcement, the depth of compressive zone, crack width and carrying capacity werechecked. Besides, the temporary strength calculation of slab was carried out in transportation, hoisting, construc-tion and maintenance. The results of calculation meet the requirements of design. It provides technical support forthe adaptability of CRTS Ⅲ slab ballastless track.