Alignment Control In Assembling Construction And Stress Monitoring Analysis In Overall Incremental Launching Construction Of Jiubao Bridge

Jiubao bridge in Hangzhou is a three-span continuous special-shaped beam-arch composite arch bridge, which adopted the construction technique of assembling on shore span-by-span and overall incremental launching into place. There was no precedent at home and abroad that the long-span continuous beam-arch composite arch bridge which adopted the overall incremental launching construction. The main bridge of Jiubao bridge set of long-span, special-shaped, wide deck in one, high requirement in construction, great difficulty in technology, and there was no relevant information to draw, so it was important to control the alignment in assembling construction and simulate the process of overall incremental launching construction. Backgrounded by the construction process of the main bridge of Jiubao bridge, this paper made a preliminary analysis and research on alignment control in assembling construction and stress monitoring in overall incremental launching construction.This paper first discussed the method of alignment control, and determined the process of alignment control in assembling construction under this method, and then described the calculation method of the assembly coordinates of the measuring points of main longitudinal beams, the main and side arch segments of the main bridge detailedly, and the alignment had been controlled according to the assembly coordinates. By the comparation of measured values and theoretical values of the measuring points, which verified that the alignment control method used in the bridge was applicable, and the control achieved a good results.Secondly, this paper introduced the plan and principle of the overall incremental launching construction of the main bridge briefly. For the structural characteristics of the main bridge, the finite element software MIDAS was adopted to establish finite element model of the bridge and simulate the process of overall incremental launching construction. The simulation results of the main bridge structure was given finally, and the results can provide theoretical support for the stress monitoring in overall incremental launching construction. Finally, this paper introduced the plan of stress monitoring in overall incremental launching construction, which mainly including strain sensor, strain collection system and monitoring method. The measuring points of the critical sections were reasonably chosed under the stress simulation results, and then the stress had been monitored in overall incremental launching construction, and the varying laws of the stress was analyzed detailedly according to the monitored results. The results of this paper can be benefit for the similar projects in the future.