安装误差对曲塔曲梁无背索斜拉桥受力影响

Influences on Installment Deviation on Stress State of Curved-pylon and Curved-girder Cable-stayed Bridge without Back-stays

为研究安装误差对主塔、主梁和拉索的应力,主塔、主梁的变形及结构可靠度的影响情况,以混合梁无背索曲塔曲梁斜拉桥——东莞水道桥为工程背景,考虑桥梁施工过程,通过有限元软件ANASYS,建立随机误差分析模型,采用蒙特卡罗函数和拉丁超立方抽样技术,分析结构力学响应的敏感性因素及百分比,并对控制截面应力进行了可靠性分析.结果表明:主塔、主梁的应力及变形和拉索的应力非对称性显著,对应的敏感参数差异较大.塔身应力与位移标准差较小,对安装误差不起控制作用.大桩号侧主梁跨中及小桩号侧结合段处压应力对安装误差水平起控制作用.因此建议,钢主梁及合拢段强制合拢安装误差分别为±20 mm和±30 mm,主塔x、y、z方向的安装误差分别为±16mm、±16mm和±30mm,这样可以满足桥梁结构施工及运营的安全要求.

In order to study influences on installation deviation on stress of pylon,beam and cable,and the deformation of pylon and beam,and structural reliability according to the construction of Dongguanshuidao Bridge,which was a curved-pylon and curved-girder cable-stayed bridge without back-stays,the installment random deviation analytical model was founded through universal the finite element analysis software ANSYS,and the construction process was thoughtful considered.Monte Carlo method and Latin hypercube important sampling technique were used,sensitivity factor and percentage of structural response were analyzed,and reliability analysis of stress of the control section was carried out.The following results can be concluded.Firstly,stress of pylon,beam and cable and deformation of the pylon and beam presents significant asymmetry,and the related sensitivity factors show high disparities.Secondly,standard deviation of deformation and stress of the cable is small,which can＇t be used to control the installation deviation level.Thirdly,installation deviation can be controlled by the pressure stress of the mid-span girder at the big stake number side and steel-concrete joint section at the small stake number side.It is suggested that installation deviation of main girder and steel-concrete joint section should be plusor minus 20 mm and plus or minus 30 mm respectively,and installation deviation of main pylon in x,y and z direction should be plus or minus 16 mm,plus or minus 16 mm and plus or minus 30 mm respectively,in order to meet the requirement of structure safety during the bridge construction and operation.