Construction Control of Hoisting and Installation of Arch Rib of a Half-Through CFST Stiff Skeleton Arch Bridge

The main bridge of the Guansheng Qujiang River Bridge in Guang'an is a half-through concrete-filled steel tube (CFST) stiff skeleton arch bridge with the main span of 320 m. The stiff skeleton of the bridge was constructed, using the fastening stay method and in the construction, the fastening stays were tensioned in place in one time. In view of the limitations of the 2 calculation methods of the forward analysis and reverse analysis for the stay forces and to accurately calculate the stay forces and the pre-raising amounts of the arch rib segments in the installation and make the completed arch geometric shape approximate the theoretic geometric shape, the adjustment method of the optimal stay forces based on the control target of the completed arch geometric shape was proposed. The MIDAS Civil 2015 was used to set up the finite element model for the whole bridge at the hoisting and installation stages of the arch rib segments, the influences of the tangent displacement on the follow-up construction stages were considered and by controlling the geometric shape mainly and the stay forces subsidiarily, the geometric shape, fastening stay forces, backstay forces and the chord stresses of the bridge were analyzed and the analysis was compared to the measured values. The results show that the measured values of the geometric shape, fastening stay forces, backstay forces and the chord stresses are highly accordant with the theoretic values, the geometric shape and structural stresses of the main arch can satisfy the relevant requirements in the design and codes, proving that the adjustment method as mentioned is feasible and effective. © 2017, Journal Press, China Railway Bridge Science Research Institute, Ltd. All right reserved.