基于应力和变形控制的预应力连续刚构箱梁桥施工技术  

Construction Technology of Prestress Continuous Rigid Frame Box Girder Bridge Based on Stress and Deformation Control

作　　者：陈晨[1] CHEN Chen(China Railway 18th Bureau Group Fifth Engineering Co. , Ltd. , Tianjin 300450, China)

机构地区：[1]中铁十八局集团第五工程有限公司,天津300450

出　　处：《中国水能及电气化》2020年第12期11-17,共7页China Water Power & Electrification

摘　　要：桥梁实际施工时,截面误差、材料容重误差、弹性模量误差、张拉误差等各种施工误差和施工步骤的改变以及偶然施工荷载的作用,都会引起桥梁结构线形与内力的改变,影响结构在施工和成桥时的状态和结构的安全。文章依托商登高速郑州段唐庄互通1号桥施工项目,介绍了主桥箱梁施工工艺,研究预应力混凝土连续刚构桥在施工过程中主梁竖向线形偏差及轴线偏移、合龙后的桥面线形、避免施工过程中主梁出现过大的应力等问题,采用三维数值模拟与施工监测相结合的方法,监测施工各阶段应力和施工位移。施工监控结论表明:施工阶段主梁压应力最大值出现在中跨合龙阶段,最大值为7.82MPa,主梁拉应力最大值出现在最大悬臂阶段,最大值为0.078MPa;无论何种施工阶段,位移极值发生在悬臂端,施工阶段最大竖向位移约为25mm,在桥墩附近位移变形值较小,约为2mm。桥梁在中跨合龙时与二期桥面铺装恒载时,变形较为接近,表明桥梁合龙后变形稳定。Section error,material volume-weight error,elastic modulus error,tensioning error and other construction errors,construction steps change and the role of accidental construction load will cause the change of the bridge structure line and internal force during bridge actual construction,thereby affecting the state of the structure in construction and completion of the bridge as well as structural safety.The paper is based on Shangdeng High-speed Zhengzhou Section Tangzhuang Exchange No.1 Bridge Construction Project.The main box girder construction technology is introduced to study the problems of prestress concrete continuous rigid frame bridge during the construction,namely main girder vertical linear deviation and axis deviation,bridge deck line after final closure and avoidance of too large stress of the girder in construction process.The 3-D numerical simulation combined with the construction monitoring is adopted to monitor the stress and displacement during different construction stages.The conclusion of construction monitoring shows that the maximum compressive stress of the main girder appears in the mid-span closure stage,namely 7.82MPa.The maximum tensile stress of the main girder appears in the maximum cantilever stage,namely 0.078MPa.The maximum vertical displacement occurs at the cantilever end regardless of the construction stage and the maximum vertical displacement is about 25mm in the construction stage.The displacement deformation near the pier is relatively small,namely about 2mm.The deformation of the bridge is closer during the mid-span closure and the second-phase bridge deck pavement constant load,thereby indicating that the deformation of the bridge is stable after closure.

关 键 词：预应力混凝土 连续刚构桥 箱梁 施工技术 

分 类 号：V445.4[航空宇航科学与技术—飞行器设计]