| 摘要 |
PURPOSE:To reduce the thermal expansion and contraction ratio of a girder, by providing heat-insulating treatment means or both upper and lower faces of the track girder and reducing a temperature difference between the upper part of the girder and the lower part thereof. CONSTITUTION:A track girder 10 is constructed in a cylindrical PC girder box comprising an upper flange 11, a lower flange 12, and left and right flanges 13, 14. A heat-insulating member 15 is laid on an upper face 11' in the shape of a layer in order to heat-insulate the upper face of the upper flange 11 and the same heat-insulating member 15' is also laid on the lower face 12' of the lower flange 12 to reduce a temperature difference between the upper and lower flanges 11, 12, In this way, the thermal expansion and contraction of the track girder 10 is reduced to obtain an accurate track structure. |
