【摘要】 为了研究钢箱主梁顶推施工过程的受力特点及其局部稳定性,结合某钢箱自锚式悬索桥,分析导梁的各个设计参数对顶推过程受力及变形的影响,分析表明导梁前端最大位移、导梁根部弯矩及钢箱梁最大拉、压应力均随顶推过程呈现周期性的变化,导梁的弹性模量及泊松比的变化对顶推过程受力及变形的影响较小,导梁的长度及其平均线重度对顶推过程受力及变形的影响较大。其次,以弹性薄板的小挠度理论为基础,分析钢箱梁顶推过程的局部稳定性,计算表明,钢箱梁未加劲前,局部稳定性不满足要求,加劲之后则满足要求。考虑板组间的约束因素、材料非线性、初始几何缺陷及残余应力等的影响,结构自重引起的应力对结构的屈曲临界应力影响很小,可以忽略不计;横隔板的设置对提高钢箱梁局部屈曲效果明显。更多还原

【Abstract】 In order to further study stress characteristics and the local stability of steel box girder during incremental launching construction, first, combined with a self-anchored suspension bridge with steel box girder,influence analysis for incremental launching process with design parameters was carried out. Analysis shows that maximal displacement at the front of guide beam, bending moment at steel guide beam root and maximum tensile stress of steel box girder as well as compressive stress of steel box girder are periodical change along with the construction process. Meanwhile, elastic modulus and Poisson ratio have a little influence on stress and deformation of steel box girder during incremental launching process, length of steel guide beam and its average weight have an important influence on stress and deformation of steel box girder during incremental launching process. Secondly, on the basis of elastic thin plate theory of small deflection, local stability analysis of steel box girders during the process of incremental launching have been carried out. Theoretical calculation shows that local stability of steel box girder does not meet the requirements before stiffening, after stiffening, the requirements is meet. Considered constraint factors between plate groups, material nonlinearity and initial geometric imperfection and residual stress, finite element analysis showed that the stress by self weight has a little influence on critical buckling stress, it can be neglected; Installing diaphragm plate to improve the effect of local buckling of steel box girder is obvious.更多还原