铁道建筑

重载铁路直线区段钢轨在重载运输条件下承受高频次、高轴重的循环荷载，导致钢轨伤损加剧。为了延长重载铁路钢轨大修周期，基于朔黄铁路（朔州—黄骅）实测钢轨重伤数据以及线路台账，对钢轨重伤量进行了统计分析，提出以钢轨重伤、通过总质量为指标的寿命评估方法。结果表明：钢轨伤损率与累计通过总质量服从威布尔分布函数，可通过数据拟合方法计算钢轨大修周期。建议重载铁路直线区段钢轨大修周期可延长至通过总质量22亿吨。当每千米重伤量未达到4～6处，但累计通过总质量达到22亿吨时进行换轨；当累计通过总质量未达到22亿吨，但每千米重伤量已经达到4～6处时也要换轨。

Under heavy haul operating conditions, straight track sections experience high-frequency cyclic loading with extreme axle loads, leading to accelerated rail deterioration. To extend rail renewal cycles in heavy haul railways, this study conducted statistical analysis of severe rail defects based on field-measured damage data and infrastructure records of Shuozhou-Huanghua heavy haul railway. A lifespan evaluation methodology was developed using severe rail defects and cumulative traffic tonnage as key performance indicators. The results demonstrate that rail failure rates follow a Weibull distribution relationship with cumulative traffic tonnage. Through data fitting analysis, the optimal rail renewal cycle was quantitatively determined. The study suggests extending the renewal cycle of steel rails in the straight track section of heavy haul railways to a to cumulative traffic tonnage of 2.2 billion ton. When the number of major defects per kilometer has not yet reached 4 ～ 6, but the cumulative total tonnage of traffic has reached 2.2 billion tons, rail replacement should be carried out. Likewise, if the cumulative total tonnage has not yet reached 2.2 billion tons, but the number of major defects per kilometer has already reached 4 ～ 6, rail replacement is also required.