超宽桥面部分斜拉桥主梁线形控制分析

Analysis of Linear Control of Main Beam of Partial Cable-stayed Bridge with Super Wide Deck

研究目的:为较好地控制超宽桥面的线形,研究超宽桥面部分斜拉桥主梁线形控制系统,分析影响主梁挠度变化的因素及全桥合龙后高程理论值与实测值存在偏差的原因,取得现场实测数据以修正计算模型参数。研究方法:以基于最小二乘法的误差控制理论为基础,结合柳州三门江大桥施工特点,运用有限元分析软件建立线形控制模型,通过实测数据与理论计算结果确保桥梁线形施工质量。研究结论:超宽桥面部分斜拉桥主梁结构变位及高程变化特点与预应力混凝土连续箱梁相接近;采用现场实测数据修正计算模型参数,达到理论计算模型与实桥相吻合,保证了主梁的安全施工;施工中要实时监测挂篮变形,并根据梁段重量对预抬量进行适当调整。

Research purposes： For the purpose of better linear control of super wide deck, the researches are done on the linear control system for main beam of partial cable - stayed bridge with super wide deck, the analyses are made for the influencing factors of deflection change and the causes for the difference in elevation between theoretic values and tested values after bridge closure, and the parameters of calculation model are modified with the tested data. Research methods： On the basis of the error control theory based on the least bi - multiplication and the construction characteristics of Sanmenjiang Bridge in Liuzhou, the linear control model is established with the software of finite - element analysis to ensure the construction quality by using the tested data and results of theoretic calculation. Research conclusions：The characteristics of the deflection and change in elevation of main beam structure of partial cable - stayed bridge with super wide deck are close to the stressed concrete continuous box beam. Using the tested data to modify the parameters of calculation model, a perfect match is achieved between theoretic calculation and the real situation of the bridge, which ensures the safe construction of main beam. In the construction, it is necessary to monitor the distortion in real time and adjust the pre - elevation volume according to the weights of the section.