杭绍台铁路椒江特大桥主桥钢桁梁设计

Design of Steel Truss Girder of Main Bridge of Jiaojiang Bridge on Hangzhou-Shaoxing-Taizhou Railway

杭绍台铁路椒江特大桥主桥为(84+156+480+156+84)m五跨连续钢桁梁高速铁路斜拉桥。该桥采用塔墩固结、塔梁分离、塔梁间设置纵向阻尼器的半飘浮体系。主梁采用钢桁梁结构,2片主桁,中心距24.3m,主桁为三角形桁式。主桁杆件采用箱形截面;桥面系采用密横梁体系,桥面板采用不锈钢复合钢板,桥面板下横桥向设置多道U形肋,在每条轨道下设纵梁;索梁锚固采用锚拉板式;上弦节点处均设置桁式结构的横联或桥门架。主桥钢桁梁位于1.3‰的"人"字坡上,变坡点位于跨中,两侧钢桁梁通过刚性旋转形成纵坡,跨中处通过合龙杆件进行折线处理实现"人"字坡相交处的顺接过渡。

The main bridge of Jiaojiang Bridge on Hangzhou-Shaoxing-Taizhou railway is a high-speed railway cable-stayed bridge that consists of five-span continuous steel truss with a span arrangement of(84+156+480+156+84)m.The bridge is a semi-floating system with pylon pier consolidation,pylon girder separation,and dampers installed in longitudinal direction between the pylon and girder.The main girder consists of structure of steel truss girder,and two triangular main trusses are assembled with the center distance of 24.3 m.The main truss members are box section,the bridge deck system consists of muti-crossbeam system,and the bridge deck is made of stainless steel clad steel plate.Meanwhile,multiple U-shaped ribs are installed transversely under the bridge deck,longitudinal beams are arranged under each track,anchor plate system is employed for anchoring the cables and girder,and cross bracings with truss or bridge portal frames are arranged at the upper chord nodes.The main bridge steel truss girder is located on the 1.3‰"人-shape"slope,the change point is located in the middle span,and longitudinal steel slopes are formed by rigid rotation of the steel truss girder on both sides.The intersection of"人-shape"slopes transform smoothly by folding the closure members in the middle span.