The Study Of The Key Technology On Long-span Prestressed Continuous Bridge In Construction Control

Prestressed concrete continuous bridge is a kind of bridge with large structure stiffness and large span capability, which develops very quickly and steadily in the past several decades. During cantilever casting of long-span prestressed concrete continuous box beams, the construction control, a complicated and dynamic system engineering, is an important measure for bridges to ensure their lineament and to meet the design requirement of the internal force. After the study and summarization of the former research, in combination with the practice of construction control of the main section of the Fuhe River Panlong Bridge, this article has conducted the research to the key technology of construction control of long-span prestressed concrete continuous bridge. Mainly made following several work:1. This article has analyzed the influence factor and the method of the error adjustment on construction control of continuous bridge.2. This article has analyzed the internal force's develop of continuous bridge in cantilever construction course, carried on the comparison to good and bad points of two kind of structure analyses method.3. This article has established a complete construction control system, the bridge actual condition carries on the track observation in the construction. Using finite element software MEDAS/civil, the entire construction process and the structure system transformation of the main section of the Fuhe River Panlong Bridge have carried on the simulation analysis. The construction cambers were evaluated and analyzed. Meanwhile, the influences of dead loads, prestressed loads and shrinkage and creep of concrete on construction camber were studied, and sensitivity analysis of construction camber in virtue of the fluctuation of main design parameter was investigated. A contrast on the actual value and the MBDAS/civil computation theory value of the box beams concrete stress, finally indicates that the actual value and the theory value identical well.4. according to GM(1, 1) model of grey system theory , to take construction camber difference as the gray differential sequence and modeling at ideal state and state of surveying, predicting the next state deviation between ideal state and state ofsurveying.Complete bridge girder elevation survey data indicate that finite element software MIDAS/civil has kind guidance to confirm segment mould elevation. Gray predict control system can be applied in construction control of long-span prestressed concrete continuous bridge, and the method is simple, the result is prominent.