（1.桥梁结构健康与安全国家重点实验室，湖北 武汉 430034； 2.中铁大桥科学研究院有限公司，湖北 武汉 430034； 3.中铁大桥局集团第五工程有限公司，江西 九江 332001）
摘 要：为了确保全飘浮体系斜拉桥A形混凝土桥塔在施工过程中线形顺直、锚点坐标准确、受力安全，以武汉青山长江公路大桥为背景，建立全桥有限元模型，对桥塔施工进行全过程控制计算，分析施工过程中的桥塔受力状态、横向预偏量、竖向预抬量、临时横撑的顶推力及拆除顺序，并对桥塔应力、线形进行监测。结果表明：塔柱实测应力与理论应力趋势基本一致，最大应力偏差为1.84 MPa；施工过程中混凝土桥塔节段倾斜度偏差小于6 mm，符合规范要求，锚点坐标控制准确；设置临时横撑,并根据施工实际需求优化横撑拆除顺序，保证桥塔线形及受力状态符合设计要求。
中图分类号： U448.27；U445.4 文献标志码： A
Construction Control for A-Shaped Concrete Pylons of a Cable-Stayed Bridge of a Full-Floating System
SHI Jing1,2, MEI Xiu-dao1,2, JIN Hong-yan3, LIU Jian-hua3, TAN Xing-xing3
(1. State Key Laboratory for Health and Safety of Bridge Structures, Wuhan 430034, China; 2. China Railway Bridge Science Research Institute, Ltd., Wuhan 430034, China; 3.The Fifth Engineering Co., Ltd., China Railway Major Bridge Engineering Group, Jiujiang 332001, China)
Abstract: To ensure the smooth vertical geometry of A-shaped concrete pylons, accurate coordinates of anchor points and safe load bearing condition of the cable-stayed bridge of a full-floating system, the Qingshan Changjiang River Highway Bridge in Wuhan was cited as an example for the study. The finite element model of the overall bridge was built, to carry out full-process control computing of the pylon construction and analyze load bearing condition of and transverse pre-offsetting value and vertical pre-lifting value for the pylons as well as the pushing force and demolition sequence of the temporary transverse struts in the construction process. And the stresses and geo-metry of the pylons were monitored. The results show that the measured stresses in the pylon columns were basically in agreement with the theoretical values, with a maximum stress deviation of 1.84 MPa. The segmental inclination deviation of the concrete pylons during the construction process was less than 6 mm, in compliant with the code requirements. The coordinates of anchor points were under accurate control. Temporary transverse struts were installed, and the demolition sequence of transverse struts was optimized in accordance with the actual construction requirements, so as to ensure that the geometry and load bearing condition of the pylons could meet the design requirements.
Key words: cable-stayed bridge; full-floating system; A-shaped concrete pylon; stress; geo-metry; finite element method; construction control