Optimization of Deck Construction Staging for Multiple-Span Continuous Steel Girder Bridge

Cracking in concrete deck has been the major concern to bridge designers as well as owners. Excessive cracking not only would affect the performance and serviceability of the bridge but also reduce the service life of the concrete deck and increase the maintenance cost. It is proven that many factors could cause the cracking of concrete deck including restrained shrinkage, temperature effects, applied live load, and improper construction sequence. Among these factors, appropriate construction staging plays an important role in minimizing the cracking of concrete deck, especially for multiple span continuous bridges. However, the construction staging has not been subjected to detailed research in the past. Therefore, it is important to evaluate the current concrete deck construction staging practice and propose an optimized construction staging for multiple span continuous bridges, if needed. In this study, the research approach adopted is aimed at investigating the cracking of a typical multiple-span continuous bridge, evaluating the construction staging, and providing an optimized practice for deck construction staging. A typical three-span continuous bridge was selected for investigation and various types of sensors were instrumented on the bridge to monitor the behavior of the structure during and after construction. The finite-element (FE) model was developed and validated with the data collected from field testing. Based on FE analysis and experimental data, the cracking of the bridge deck was investigated and alternative construction staging scenarios were simulated and compared. Moreover, based on analysis results, an optimized deck construction staging practice was recommended for future use.