客货共线铁路弹性支承块无砟轨道更换支承块特性研究

Study on Characteristics of Replacing Bearing Block for Ballastless Track with Elastic Bearing Block for Passenger and Freight Railway

为进一步提高更换支承块的现场作业效率,降低施工成本,采用有限元方法对更换支承块问题进行理论研究,得到合理抬轨间距、扣件松开范围及相关变化规律等。研究表明,为减小钢轨和扣件的变形及受力,建议采用两点抬轨方式,抬轨间距宜控制在1.2~2.4 m;钢轨弦弧差、钢轨最大拉应力随扣件松开范围增大而线性增加,变化趋势类似反比例函数;扣压区扣件最大上拔力随扣件松开范围的线性增加,在扣件松开27.0 m之前,减小趋势较大,反之,减小趋势较小;钢轨弦弧差、钢轨最大拉应力、扣压区扣件上拔力随抬轨量增大呈线性增加关系;在抬轨量16 cm、抬轨间距1.8 m条件下,为满足钢轨受力和扣压区扣件处于受压状态,扣件松开长度不宜小于36.6 m;抬轨量每增加1.0 cm,扣件松开长度宜增加0.6~1.2 m(1~2组扣件)。

In order to further improve the field operation efficiency of replacing the bearing block and reduce the construction cost, the finite element method was used to study problems of replacing the support block, a reasonable rail lifting spacing, the fastener loosening range and related change laws were obtained. The results show that: in order to reduce the deformation and stress of rail and fastener, two-point rail lifting method is recommended, the rail lifting distance should be controlled between 1.2 m and 2.4 m;the variation trend of the chord arc difference, and maximum tensile stress of rail increases linearly with the loosening range of fastener, which is similar to the inverse proportional function;the maximum uplift force of fastener in the fastening area increases linearly with the loosening range of fastener, and the decreasing trend is larger before 27.0 m, on the contrary, the decreasing trend is smaller;the chord arc difference of rail, the maximum tensile stress of rail and the uplift force of fastener in the fastening area increase linearly with the increase of rail lifting amount;under the condition of 16 cm rail lifting amount and 1.8 m rail lifting distance, the length of fastener loosening range should not be less than 36.6 m in order to satisfy requirements of the stress of rail and the compression of fasteners in the fastening area;the length of fastener loosening range should be increased by 0.6~1.2 m(1 ~ 2 groups of fasteners) for every 1 cm increase of rail lifting amount.