天津团泊新桥施工控制

Construction Control of New Tuanbo Bridge in Tianjin

为了使团泊新桥(独柱斜塔空间扭面背索混合梁斜拉桥)的成桥线形和索力、应力均达到设计及规范要求,根据该桥结构特点及主要施工过程,确定该桥施工控制以桥塔线形控制为主,索力的确定采用基于正装法及最小二乘法原理的优化方法,该桥斜拉索控制张拉索力的确定分桥塔悬臂施工和体系转换施工2个阶段进行。通过参数识别确定将背索和前索索力作为重点识别的结构参数。桥塔目标线形控制主要通过对塔柱拼装线形控制与索力调整控制来实现。塔柱施工过程中需采用合理的索力张拉顺序保证桥塔施工中及成桥状态的内力安全,桥塔线形控制包括塔柱拼装线形与塔柱整体姿态2部分。团泊新桥成桥后各控制参数满足设计要求。

To ensure that the geometric shapes,cable forces and stress of the completed bridge of the New Tuanbo Bridge（a hybrid girder cable-stayed bridge with a single inclined column pylon and spatial twisted back stays） in Tianjin could meet the relevant requirements in the design and codes and in the light of the structural characteristics and the major construction process of the bridge,it was determined that the geometric shapes of the pylon of the bridge were to be mainly controlled in the construction.The cable forces of the stay cables were to be determined,using the optimization method based on the forward assembling calculation method and the principles of the least square method.The tensioned cable forces were to be controlled in two stages of the cantilever construction and system transformation of the pylon.The cable forces of the back stays and front stays were to be regarded as the critical structural parameters to be particularly identified in the parameter identification.The control of the target geometric shapes of the pylon was to be realized through the control of the assembling geometric shapes of the pylon column and the cable force adjustment.In the construction process of the pylon,the rational tensioning sequences of the stay cables were necessarily to be adopted so as to ensure the safety of the internal forces of the pylon in both the construction and completed bridge state.The control of the geometric shapes of the pylon included two parts of the assembling geometric shapes and the global posture of the pylon column.After the construction of the bridge was finally completed,the various control parameters of the bridge proved to meet the requirements in the design and codes.