上坡米1号大桥边跨合龙和现浇段设计与施工方案优化

Designand Construction Method Optimizingof The Side Span Closure and Cast-in-site Segmentsof Shangpomi Num. 1Bridge

上坡米1号大桥跨径布置为(6×40 m)T梁+(72+120+120+72)m预应力混凝土连续刚构+(3×40 m)T梁,连续刚构主桥两个过渡墩分别为69.91、58.37 m,原设计边跨现浇段和合龙段长分别为11 m和2m,施工采用吊架承重结构体系。由于施工过程中跨配重吨位大,施工控制比较难,一旦在某个施工环节出现疏忽,产生的轻则是不可逆转的质量问题,重则是质量安全事故。为此,工程师们围绕缩短边跨现浇段长度来优化边跨合龙与现浇段设计施工方案,并成功研究出先合龙中跨、挂篮不对称悬浇18号梁段3.5 m+墩顶托架现浇段5.5 m+挂篮施工合龙段4 m的边跨合龙与现浇段设计施工方案。

Theshangpomi num. 1 bridgeis made up with（6×40）m T beam, （72 ＋ 120 ＋ 120 ＋ 72） mprestressed concrete continuous rigid frame bridge and （3 × 40） m T beam, while the high of the two transition piers of prestressed concrete continuous rigid frame bridge are 69.91 m and 58.37 mCon- structingthell medge cast-in-site segments and 2 m closure segmentswithhanger are the original design scheme, which has difficult construction technology, and complex construction process. Once in a con- struction section appears negligence, producing the quality problem is irreversible, even the quality and safety accidents. Therefore, engineers around the shorter side span cast-in-place length to optimize side span closure with cast-in-situ period of design and construction scheme. At last, the schedule of pouring concrete of theside-span unequally 3.5 mwithbracket at first, thenpouring concrete 5.5 m at the top of the piers, after closuring the mid-span was proposed.