Construction Control Study Of Continuous Rigid Frame Bridge(70+2×120+70)m Crossing Danla Highway

Prestressed concrete continuous rigid frame bridge usually use cantilever construction method in construction, its linear and internal forces is closely related with structure weight, prestressed tension, shrinkage and creep, temperature changes, secondary dead load, traffic loads, specific cantilever construction process and the system conversion. Although prestressed concrete continuous rigid frame bridge construction process can be simulated by finite element software, but there are some differences between model parameters and reality, and construction site measurement error, it may lead to some differences between actual and design linear and internal forces of the bridge, construction process simulation analysis for prestressed concrete continuous rigid frame bridge is necessary, through linear and internal forces monitoring in construction site, timely detect and adjust the bias that may arise during construction, to ensure linear and internal forces of the bridge to meet the relevant technical specifications after the bridge was built.Taking Qu Chuang(70+2×120+70) meter concrete continuous rigid frame bridge as the background, use Midas/Civil calculations software simulate its construction process, and how to establish an appropriate calculation model has been studied, mainly including:(1) Under concrete pouring, prestressing tendons tension, cradle traveling conditions, its vertical deflection and stress theoretical value and precamber;(2) Select the shrinkage and creep, jacking force, secondary dead load, traffic loads etc. typical conditions, analyzed the variation of linear and internal forces of the main beam under cantilever construction stage and built;(3) Deflection and stress variation of the main beam under the local and global temperature effects;(4) Deflection and stress variation of the main beam under different control stress, tunnel friction and pipeline coefficient of variation. Finally, in reference of the results of monitoring, combined with the monitoring results of linear and stress in field, timely analyze, evaluate and correct abnormalities that may occur during the construction to ensure that the bridge construction and built,its linear and internal force meets the design requirements.