Study On Construction Techniques Of Cast-In-Situ Concrete Continuous Beam On Passenger Dedicated Line

With the practicing of "four vertical and four horizontal" high-speed railway passenger transport network gradually, China's passenger special railway line construction on an unprecedented scale. As a fully enclosed traffic patterns of the high-speed railway, line's level and vertical section parameters require a high smoothness of the track, leading to a significantly increase of the proportion of the bridge. In a flood discharge, navigation, traffic lines (across existing lines) and across deep valley arid so can not have bracket construction case, continuous beam with its unique advantages will be widely adopted. In view of the uniqueness of construction method of the continuous beam coupled with the overall performance of high-speed railway bridges, structural stiffness, durability, into the bridge linear, driving comfort and other aspects of the strict requirements, study on the construction technology of cast-in continuous beam is necessary.At present, although the cantilever construction method is relatively mature among the continuous beam construction methods, but in view of the high-speed railway's strict requirements on construction quality for continuous beam, a lot of key issues need to be addressed during the construction process.This thesis will combine the construction of continuous beam (40m+72m+40m) of SHIGAN special bridge on Beijing-Shanghai High Speed Railway,mainly focus on controlling and studying the key techniques during the construction of the continuous beam. Selected the triangle hanging basket style after a comprehensive consideration of the various factors, examined the optimization of design and performance of it, results accord with standard requirements;formulated strict control measures from the aspects of concrete pouring method,concrete curing and so on,ensured the high-performance of it;avoided the influence of temperature changes,creep and shrinkage of concrete,uneven settlement of foundation on the beam's linear and stress;through adopting feasible monitoring methods and means on linear control such as adjusting the template elevation,ensured the closed accuracy of the fold section, got positive linear and beautiful appearance after the bridge closed up.Finally,the thesis summarized the quality control measures adopted during the construction process,formed more mature key techniques for similar engineering.