铁道建筑

针对高速铁路路桥过渡段基础不均匀沉降、路基翻浆冒泥引起的脱空病害，本文同时考虑两种成因，建立高速铁路车辆-轨道-过渡段基础耦合模型，揭示轨面不平顺、支承损失以及二者共同作用对系统动力响应的影响。结果表明：基础不均匀沉降和路基翻浆冒泥引起的脱空病害，对路桥过渡段结构的影响主要体现在轨面折角引起的轨道不平顺变化以及路基与轨道结构之间的支承状态改变；车体垂向加速度对基础不均匀沉降的影响最为敏感，轨面折角为1.5‰时车体垂向加速度为1.513 m/s²，超过规范限值；有脱空时，轮轨垂向力为无脱空时的1.60～1.65倍，可能导致轨道结构损伤及路基长期沉降；相对于基础不均匀沉降，路基翻浆冒泥对车体垂向加速度和轮轨垂向力的影响较小；轨面不平顺与支承损失共同作用时，轮轨垂向力无明显变化，而对车体垂向加速度影响较大，脱空高度大于15 mm时车体垂向加速度超过规范限值。

This paper simultaneously considered two causes of void defects in high speed railway road-bridge transition sections, namely foundation uneven settlement and subgrade mud pumping, and established a high speed railway vehicle-track-transition subgrade coupling model, to reveal the influences of rail irregularity, support loss and their coupling effect on the system dynamic response. The results show that the impacts of void defects induced by foundation uneven settlement and subgrade mud pumping on the transition structure are mainly reflected in the variation of track irregularity caused by rail surface deflection angle and the change of support condition between subgrade and track structure. The car-body vertical acceleration is the most sensitive to foundation uneven settlement. When the rail surface deflection angle reaches 1.5‰, the car-body vertical acceleration is 1.513 m/s², exceeding the specification limit. In the presence of void defects, the wheel-rail vertical force is 1.60～1.65 times that under the non-void condition, which may induce track structure damage and long-term subgrade settlement. Compared with foundation uneven settlement, subgrade mud pumping has a relatively slighter influence on car-body vertical acceleration and wheel-rail vertical force. Under the combined action of rail irregularity and support loss, the wheel-rail vertical force has no significant change, while the car-body vertical acceleration is greatly affected, and the value exceeds the specification limit when the void height is greater than 15 mm.