哈大铁路客运专线CRTSⅠ型轨道板温度变形及应力数值分析

Analysis of Temperature Deformation and Stress Value of CRTSⅠ Track Slab on Harbin-Dalian Passenger Dedicated Line

建立CRTSⅠ型轨道板有限元模型,对0.5℃/cm温度梯度荷载作用下的轨道板变形及应力进行分析。计算结果表明,轨道板"上冷下热"温度状况下变形为中部下沉四角翘曲,最大翘曲量为1.37 mm,上表层出现拉应力,最大值为1.97 MPa;"上热下冷"温度状况下变形为中部上拱四角下沉,最大上拱量为0.65 mm,下表层出现拉应力,最大值为2.05 MPa;轨道板抗上拱能力比抗四角上翘能力强。将理论计算与现场实测数据进行比较,二者吻合较好。分析认为在板体温度均匀或"上冷下热"情况下灌注CA砂浆有利于防止四角离缝过大,指出板上下表面纵横向均将受到温度拉、压应力的反复作用,为防止板体开裂,须采用双层双向预应力体系并严格保证施加质量。

CRTSⅠ track slab finite element model is established to analyze track deformation and stress under 0.5 ℃/cm 0.5 of temperature gradient load.The results of calculation have suggested that the deformation of track subject to 'up cool and down hot' is in the pattern of settling in the center and warping at four corners with the maximum warping of 1.37mm,the upper layer is subject to tensioning stress of maximum 1.97 MPa;while the deformation under 'up hot and down cool' condition is shown in the pattern of cambering in the center and settling at four corners,the upper layer is subject to tensioning stress of maximum 2.05 MPa;the track slab shows stronger capacity for anti-cambering than that for anti-warping at four corners.The theoretical calculation is well coherent with site measurements.The analysis shows that when the temperature of track slab is uniform or when 'up cool and down hot' occurs,grouting CA mortar will help prevent gapping at four corners;when the up and down surfaces of the track slab is subject to repeated acts of temperature tensioning and pressing stress,pre-stressed system of double-layer bi-direction shall be employed to prevent slab body from breaking and guarantee construction quality.