Construction Control Of Long Span Continuous Bridge And Parameter Sensitivity Analysis Based On RSM

In order to ensure bridges’alignment and stress state meet well with the ideal condition and to make sure the security and stability during cantilever construction, bridge construction control is becoming more and more significant. Based on the construction of the Southern Part of Longhai Road Main Line Bridge, this paper studies the construction control of the long span prestressed concrete continuous girder bridge. The main research contents and results are as follows:1. Based on finite element theory and construction characteristics of the Southern Part of Longhai Road Main Line Bridge, construction process simulation was made to get the deformation and stress state of the control section.2. Considering the mechanical characteristics and construction schedule, monitoring scheme was made to control the entire construction process. The items to be monitored include stress, alignment, temperature and temporary pier stability. Through effective construction monitoring, the development of actual stress state of all stress monitoring sections and the ideal condition meet well during the construction stage. And the alignment state meets the requirement of design. The temperature change imposes little influence on the torsional deformations of the beam body. The deformation on both sides of the temporary piers is basically identical and the overall stability is good.3. This paper studied the calculation method of measured stress during the stress monitoring. The calculation method considers of concrete shrinkage and creep and Matlab has been applied for calculation. Considering concrete shrinkage and creep, the difference between measured stresses and calculated ones is small. Getting the real stress state of the bridge from measured strain by this method is feasible.4. Providing formwork placing elevation is an important task of the alignment control. To improve the efficiency of formwork placing elevation management and to ensure the accuracy and security of the data, the formwork placing elevation management system was built based on Access.5. This paper proposes a parameters sensitivity analysis method based on response surface. This simplifies the process of parameter sensitivity analysis. According to the parameter sensitivity analysis of the Southern Part of Longhai Road Main Line Bridge, the sensitive parameters have a linear relationship with the stress and deformation and the influence is different on each construction stage. In general, concrete elastic modulus and section inertia moment are the primary influential parameters for deflection sensitivity, while the concrete bulk density and prestressing force are secondary ones. Concrete bulk density and prestressing force are the primary influential parameters for stress sensitivity, while the concrete elastic modulus and section inertia moment are secondary ones.