CRTSⅠ型板式无砟轨道板角离缝原因与治理措施

Cause Analysis of Gaps in Slab's Four Corners and Treatment Measures for CRTS Ⅰ Ballastless Slab Track

为了研究轨道板板角离缝的形成原因及治理措施,选取一高速铁路CRTSⅠ型板式无砟轨道结构,对其砂浆变形、板面高程、轨道板不同部位温度等指标进行24 h连续测试,并对测试结果进行分析。结果表明:轨道板板面与板底温差的周期性变化是导致轨道板周期性变形的主要原因;轨道板板面高程随时间变化呈现大致规律的波动变化;相对板面中心,板角在夜间翘起明显,板角离缝宽度与离缝值在夜间同步增大;充填层CA砂浆横向和竖向变形遵循热胀冷缩规律,其变形量较小,不是板角离缝产生的主因;不同涂层对混凝土表面温度具有降低作用,可用于改善板角因温度翘曲而产生的离缝程度。

A representative CRTSⅠballastless slab track of high speed railway was selected to study the cause of gaps in slab s four corners and the corresponding treatment measures.The mortar deformations,the surface elevations and the temperatures of different track slab parts were measured continuously in 24 h.The results of analysis show that the major cause of slab periodic deformation is the periodic change of temperature difference between surface and the bottom of track slab.Compared with the center of slab surface,the corners of track slab warp signif icantly at night,and the width and the depth of gap increase synchronously at night.The transverse and vertical deformations of the f illing layer CA mortar follow the rules of thermal expansion and cold shrinkage,and the small deformation of CA mortar is not the major cause of the gaps at four corners.Different coatings can decrease the surface temperature of concrete slab,which could be used to improve the gap degrees of slab corners caused by temperature warping.