Research Of Construction Control Of Balance Turning Construction Of Concrete Arch Bridges With Open Thin-walled Section

The rotation construction of open thin-walled section arch bridge is a new construction technology. The technical difficulty and the construction risk of rotation are largely affected by bridge span length and the weight of the rotating part. In addition to the well-designed work and construction, a reasonable and comprehensive monitoring and controlling system is a must to the implementation of rotation. At the same time the analysis of this technology will bring us the developments and improvements of the rotation construction.This paper based on the construction of Huajiang Bridge. The analysis results of calculation and evaluation of the critical stage of construction direct the construction site monitoring, through which a large amount of accurate data is provided. It will provide references for the bridge constructions of the same type. The main contents of this paper are as follows:(1)Based on the construction feature of the Arch Bridges with Open Thin-walled section, the essay states the process of Construction technology . The essay is also combined with project cases to analyze the emphasises and difficulties of bridge monitoring.(2)According to the design principles of flat rotating bridge, this paper presents a way of gravitational center computation called Elastic Supporting Method. The gravitational center of the Rotation system was modeling calculated and parameter analyzed by this method, the gravitational center of the Rotation system was accurately adjusted by counterweigh.(3)The static analysis and stability analysis of the bridge were carried out, using MIDAS and ANSYS. Cable force calculation method was discussed and the value of cable tension was obtained. The stress, deformation, the main influence factors of the back wall and the arch ring were analyzed when the rotating structure in tension phase and falsework dismantling, local stress of top turntable was analyzed either. This paper studied the mechanical characteristics of the arch ring when there is dynamic effect, and the stability of arch ring in falsework dismantling phase, and provided theoretical guidance for construction.(4)Under the guidance of the theoretical calculation,the value of cable tension, the stress, linear of the key section of back wall and the arch ring were monitored especially in all kinds of engineering cases.Measured data analysis indicated that: The rotation is smooth, measured linear only have a small deviation from theoretical linear and the distribution of key sections' stress is reasonable. So it is proved that the monitoring method of Huajiang Bridge this paper studied is scientific and reasonable.