Stress Monitoring for the Whole Construction Process of Simply Supported to Continuous T-Beam Bridge

摘要

In order to research on the stress change and influencing factor of whole construction process of simply supported to Continuous system T-beam bridge, combined with Guizhou Bai-long bridge, the stress change is carried out the real time inspection in each construction stage, and the finite element model is established to analyse Stress changes in whole construction process. The monitoring value is more consistent with the theoretical value in each stage, monitoring dates and theoretical calculations showed that pre-stressed is the main factor of stress changes in construction process. Pre-stressed tension in negative moment region has obvious influence on the stress of middle span, the stress of top and bottom plates in wet joints will be equivalent after tendons tension in negative moment Region. Simply supported to Continuous system combined with the advantages of the convenience for construction of simply supported beam bridge and continuous bridge's reasonable load and driving comfort, is widely used in modern bridge, particular in the construction of the highway. At present, there are more studies on technical aspects of design and construction about simply supported to continuous system T-beam bridge[1-5], but to Pre-stressing tension process[6], especially stress monitoring and analysis in whole construction process are less involved. The stress change is carried out full-time tracking and monitoring in construction phases, such as T-beam cast, conservation, tension, set up, system conversion, shrinkage and creep in late stages combining with Guizhou Bai-long bridge, and the finite element method is adopted to simulate the whole construction process, the monitoring value is more consistent with theoretical value, analysis showed that in the whole construction process, pre-stressed is the main factors of affecting the stress of main beams. Pre-stressed tension in negative moment region has obvious influence on the stress of middle span, the compressive stress of the top increased and the bottom reduced. the stress of top and bottom plates in wet joints will be equivalent after tendons tension in negative moment Region.