高速铁路路基地段双块式无砟轨道线间排水优化

Drainage Optimization between Double-block Ballastless Track Lines in Subgrade Section of High Speed Railway

以国内广泛应用的CRTS双块式无砟轨道为例,研究路基基床表面翻浆冒泥的产生机理,并结合无砟轨道防排水的相关研究成果和既有线病害整治经验,针对线间防排水提出一系列的优化方案。研究结果表明:(1)受高铁线路纵坡值的影响,位于小坡度值段的路基线间封闭层容易产生积水滞留,在高速运行动车组反复动应力影响下,是导致积水下渗,路基基床表面出现翻浆冒泥的主要原因;(2)通过线间采用纤维混凝土、优化横向切缝嵌缝材料尺寸、集水井附近配筋加强措施,可增强封闭层密封防水性,改善其早期抗裂性能、抑制后期裂纹发展并从整体上改善混凝土的服役期工作性能;(3)通过加密集水井、加厚封闭层并在封闭层顶面形成纵坡排水或在封闭层内部设置排水明沟排水均可有效增加排水效果,满足线间积水快速引排的需要。

By taking CRTS double-block ballastless track widely used in China as an example,this paper studies the mechanism of mud pumping on the surface of subgrade bed,and puts forward a series of optimization schemes for waterproofing and drainage between lines based on relevant research results of ballastless track waterproofing and drainage,and the experiences of existing line defects treatment.The results show that:(1)Due to the influence of the longitudinal slope value of the high-speed railway line,the closing layer between the road baselines in the section with small slope value is likely to generate water retention,which is the main cause of the water infiltration and mud pumping on the surface of the subgrade bed under the effect of the repeated dynamic stress of the high-speed EMU.(2)By using fiber reinforced concrete between lines and optimizing the size of transverse slit seam material and reinforcement near the water collecting well,the sealing and waterproof performances of the closing layer is enhanced,the early crack resistance is improved,the later crack development is restrained and the working performance of concrete in service period is improved as a whole.(3)The drainage effect can be effectively increased by infilling the water collecting well,thickening the closing layer and forming longitudinal slope drainage on the top of the closing layer,or setting open drainage ditches inside of the closing layer to meet the needs of rapid drainage of water between lines.