摘要
在雨水充沛或排水不畅地区,积水会造成无砟轨道层间离缝扩展显著加速。针对含层间离缝的CRTS Ⅲ型板式无砟轨道的水力特性问题,建立列车荷载与水耦合作用下的CRTS Ⅲ型板式无砟轨道-离缝积水双向瞬态流固耦合计算模型,揭示无砟轨道层间离缝内动水压力和水流速度的分布及其峰值的变化规律,并分析列车轴重、行车速度、离缝形态及积水深度对动水压力和水流速度的影响。研究结果表明:随着列车的趋近与远离,层间离缝内固定点处的动水压力与水流速度呈周期性的正负交替变化;动水压力沿着离缝出口方向逐渐减小,其峰值发生在离缝尖端处,而水流速度沿着离缝出口方向逐渐增大,其峰值发生在离缝出口处;动水压力与水流速度峰值随列车轴重增加而线性增大,轴重每增加1 t,动水压力和水流速度峰值分别增加2.850 kPa、0.085 m/s;动水压力峰值与车速呈二次方增大关系,而在车速小于300 km/h时水流速度峰值与车速基本上呈线性关系,超过该车速后流速增长趋势较之前更大;动水压力、水流速度峰值与离缝开口量呈反比关系;动水压力与水流速度峰值都随着离缝深度和离缝积水深度增加而显著增大,且两者都与离缝深度呈3次多项式增大关系,与离缝积水深度呈2次方增大关系。研究结果可为CRTS Ⅲ型板式无砟轨道在列车荷载与水耦合作用下的层间离缝扩展分析以及养护维修工作提供依据和参考。
In areas with abundant rainfall or poor drainage,standing water significantly accelerates the expansion of interlayer cracks in slab tracks.To solve the hydraulic characteristics problem of CRTSⅢslab track with interlayer cracks,a two-way transient fluid-solid coupling calculation model was established.The model considered the coupling effect of train load and water accumulation in the crack.The distribution of dynamic water pressure and water velocity and the change of peak value in the gap between layers of ballastless track were revealed.The effects of train axle weight,train speed,crack morphology,and depth of water accumulation on dynamic water pressure and water velocity were analyzed.The results show that the dynamic water pressure and water velocity at the fixed points in the interlayer crack exhibit alternating positive and negative periodic changes as the train approaches and moves away.The dynamic water pressure decreases gradually along the exit direction of the seam,with its peak occurring at the tip of the crack,while the water velocity increases gradually along the exit direction of the seam,with its peak occurring at the seam outlet.The peak values of dynamic water pressure and water velocity increase linearly with the increase of axle weight.When the axle load increases by 1 t,the peak values of dynamic water pressure and water velocity increase by 2.850 kPa and 0.085 m/s,respectively.The peak dynamic water pressure has a quadratic increasing relationship with the vehicle speed,while the peak water velocity is linearly related to the vehicle speed at speeds less than 300 km/h,and the trend of flow velocity growth is more rapid after exceeding this speed than before.The peak values of dynamic water pressure and water velocity are inversely proportional to the opening volume.They both increase significantly with the increase of the crack depth and crack water depth.The relationship between them follows a cubic polynomial function with crack depth and a quadratic function with crack water depth.These findings provide a basis and reference for analyzing the expansion of interlayer cracks in CRTS III slab tracks under the coupling effect of train load and water,as well as for curing and repair work.
作者
宋力
饶佳琪
刘冉
蒋丽忠
余志武
SONG Li;RAO Jiaqi;LIU Ran;JIANG Lizhong;YU Zhiwu(School of Civil Engineering,Central South University,Changsha 410075,China;National Engineering Research Center of High-speed Railway Construction Technology,Changsha 410075,China)
出处
《中南大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2024年第7期2600-2611,共12页
Journal of Central South University:Science and Technology
基金
国家自然科学基金资助项目(52078492,52378208,51778631,51378506,U1934217)
中国中铁股份有限公司重大专项(2020-重大-2)。
