冬季高速铁路桥上CRTS Ⅱ型板式无砟轨道温度分布试验

来源期刊:中南大学学报(自然科学版)2021年第3期

论文作者:周凌宇 赵磊 余志武 张营营 邹莅凡 袁亚慧

文章页码:748 - 758

关键词:高速铁路桥;CRTS Ⅱ型板式无砟轨道;寒冷季节;模型试验;温度分布

Key words:high-speed railway bridge; CRTS Ⅱ ballastless track; cold season; model test; temperature distribution

摘    要:为研究冬季高速铁路桥上CRTS Ⅱ型板式无砟轨道温度分布规律,制作无砟轨道-预应力混凝土简支箱梁结构1?4缩尺试验模型,开展冬季低温气候无阳光直射环境下的温度分布试验,研究CRTS Ⅱ型板式无砟轨道结构的温度变化规律,提出该型无砟轨道在高速铁路桥上的温度分布形式。研究结果表明:1) 寒冷季节高速铁路桥上CRTS Ⅱ型板式无砟轨道内的竖向温度、温差和温度梯度均呈“S”形非线性分布;横向温度呈抛物线形非线性分布;2) 无砟轨道的三维温度分布呈马鞍形曲面分布;轨道系统不同深度位置的温度均呈正弦曲线式周期性变化,且该变化滞后于环境气温;3) 轨道板和底座板受正温度梯度作用,CA砂浆层受负温度梯度作用;冬季低温气候环境下,轨道板与CA砂浆层间的竖向温度梯度为正温度梯度,极值为25.0 ℃/m;CA砂浆层与底座板之间竖向温度梯度为负温度梯度,极值为-27.0 ℃/m;CA砂浆层的温度传递阻滞效应会加剧无砟轨道各层之间的温度梯度效应,在研究高速铁路桥上CRTS Ⅱ型板式无砟轨道温度作用效应过程中应注重CA砂浆的影响。

Abstract: To study the temperature distribution of the China Railway Track System Type Ⅱ (CRTS Ⅱ) ballastless track on high-speed railway (HSR) bridge in winter, a 1?4 scaled specimen of ballastless track with prestressed concrete simply supported box girder structure was made. The temperature variation laws of CRTS Ⅱ ballastless track on the HSR bridge were researched by temperature test in winter without direct sunlight. The results show that: 1) The vertical temperature, temperature difference and temperature gradient of the CRTS Ⅱ ballastless track are all "S" nonlinear distribution in winter, and its transverse temperature distribution is nonlinear distribution of parabola. 2) The 3-D temperature distribution of the ballastless track is saddle surface, the temperature at different depths of the track system changes periodically in a sinusoidal shape, and this change lags behind the ambient air temperature. 3) The temperature gradient in track slab and bottom base are positive, while it is negative in CA mortar. The vertical temperature gradient between track slab and CA mortar is positive, and the maximum value is 25.0 ℃/m. However, it is negative between the CA mortar and bottom base, and its maximum value is -27.0 ℃/m. In addition, the temperature transfer retardation effect of the CA mortar layer might increase the temperature gradient effect between the various layers of the ballastless track. Therefore, in the process of studying the temperature effect of the CRTS Ⅱ ballastless track on the HSR bridge, the influence of the CA mortar should be paid attention to.

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