1.2　Structure of CRTSⅡBi-blockBallastless Track on Bridge

The CRTSⅡbi-block ballastless track on bridge is composed of steel rail，fastener，bi-block sleeper，track bed slab and pedestal.The concrete pedestal shall firstly be constructed on bridge，then the concrete track bed slab shall be constructed on it，whose structure refers to Figure 3 and Figure 4.

The thickness of track bed slab in bridge section is 260 mm，18 vertical rebars，C40 concrete shall be used，the concrete track bed slab shall be poured one piece after another，the length of standard concrete track bed slab is 6.44 m，for other girder type other than 32 m simply supported beam，the length of track bed slab at girder terminal can be adjusted based on girder length，slab length shall not be less than 4.0 m and shall not be more than 8.0 m，one 10 cm expansion joint shall be set between adjacent two concrete track bed slabs，and two anti-shear convex plates shall be set for every track bed slab unit.

The concrete pedestal for bridge shall be poured on the concrete protective layer of bridge，and shall be connected with the protective layer by connecting rebar，and the isolated layer laid on pedestal surface will separate it with concrete track bed slab； the expansion joint shall be set between concrete pedestal，the setting position shall correspond to that of track bed slab，and the width shall be the same as the track bed slab.C40 concrete shall be used for the pedestal，two grooves shall be set on the pedestal which corresponds to the anti-shear convex plate of the track bed slab，geotextile shall be laid on between the track bed slab and the pedestal，and the rubber subplate shall be pasted at side face of the groove.

Ballastless track structural height in bridge section：830 mm（from top surface of inner rail to girder surface）.The high rail superelevation on bridge shall be set on concrete pedestal.