摘要
大跨度预应力混凝土连续梁以其跨越能力强、行车舒适性好等特点,广泛应用于铁路桥梁工程中,但由于其温度跨度大,导致无缝线路钢轨附加应力增大,严重制约了大跨度预应力混凝土连续梁发展。本文以某高速铁路大桥(80+136+80)m连续梁为背景,结合现场施工情况对四种不同支座约束连续梁体系无缝线路钢轨应力进行对比分析,并得出以下结论:温度跨度越大,伸缩和制动附加应力越大;速度锁定器可显著减小制动附加应力,但对改善钢轨总应力效果不明显,可在长大坡道和加减速地段采用;小阻力扣件可显著减小伸缩附加应力,对改善钢轨总应力效果较为明显;双固定墩和纵向活动支座+速度锁定器的连续梁体系可降低大跨度桥梁温度跨度,明显减小无缝线路钢轨受力。经综合比较,结合本桥线路平纵断面和现场施工情况,本桥维持小阻力扣件不设温度调节伸缩器方案。
Long span prestressed concrete continuous beam is widely used in railway bridge engineering because of its strong spanning capacity and good driving comfort. However, due to its large temperature span, the additional stress of CWR rail increases, which seriously restricts the development of long-span prestressed concrete continuous beam. Based on the(80+136+80)m continuous beam of a high-speed railway bridge, combined with the field construction situation, this paper compares and analyzes the stress results of CWR rails of four different support constrained continuous beam systems, and draws the following conclusions:(1) the larger the temperature span, the greater the additional stress of expansion and braking;(2) the speed lock can significantly reduce the additional braking stress, but it has no obvious effect on improving the total stress of the rail. It can be used in the long ramp and acceleration and deceleration section;(3) the small resistance fastener can significantly reduce the additional stress of expansion and contraction, and has an obvious effect on improving the total stress of rail;(4) the continuous beam system of double fixed piers and longitudinal movable support+speed lock can reduce the temperature span on the long-span bridge and significantly reduce the stress of CWR rail. After comprehensive comparison of various schemes, in combination with the horizontal and vertical lines of the bridge and on-site construction conditions, the scheme of maintaining small resistance fasteners without temperature regulator is adopted for the bridge.
作者
廖凯
龚小平
姜海君
LIAO Kai;GONG Xiaoping;JIANG Haijun(China Railway Fifth Survey and Design Institute Group Co.Ltd.,Beijing 102600,China)
出处
《铁道建筑技术》
2022年第8期89-92,97,共5页
Railway Construction Technology
基金
中国铁路总公司科技研究开发计划课题(2017G002-H)。
关键词
桥上无缝线路
温度跨度
小阻力扣件
约束体系
方案对比
CWR on bridge
temperature span
small resistance fastener
restraint system
scheme comparison
