大跨度斜腿桥墩施工关键技术研究

Research on Key Construction Technologies of Long Span Oblique⁃leg Pier

大跨度斜腿桥墩可以跨越不可改迁的既有地下管道,因其结构形式的特殊性,施工难度大。本文以泉州湾跨海大桥300#墩为例,研究大跨度斜腿桥墩设计与施工的关键技术,并通过数值模拟对大跨度斜腿桥墩施工支架进行了强度、刚度和稳定性计算与分析。结果表明:主横梁的组合应力最大为157 MPa,小于Q235B强度设计值;支架搭设完毕,支架空载工况下支架竖直方向的位移最大值为0.559 mm;混凝土浇筑完毕,支架正常工作工况下支架竖直方向的位移最大值为5.092 mm,支架强度和刚度,以及斜撑、钢立柱和平联的稳定性均满足规范要求。

The long-span oblique-leg pier can cross the existing underground pipeline which can not be relocated.Due to the particularity of its structural form,the construction is difficult.Taking the 300#pier of Quanzhou Bay sea crossing bridge as an example,the key technologies of the design and construction of long span oblique-leg pier were studied,and the strength,stiffness and stability of the construction support of long span oblique-leg pier were calculated and analysis through numerical simulation.The results show that the maximum combined stress of the main cross girder is 157 MPa,which is less than the design value of Q235B strength.After the support is erected,the maximum displacement in the vertical direction of the support under no-load condition is 0.559 mm.After pouring concrete,the maximum displacement in the vertical direction of the support under normal working conditions is 5.092 mm,the strength and stiffness of the support and the stability of diagonal bracing,steel column and longitudinal bracing under normal working conditions of the support meet the requirements.