A Study In Constrction Control Of Very Long Span Prestressed Concrete Continuous Girder

In recent years, very large span prestressed concrete continuous girder bridge is widely applied because of its obvious advantages , such as less deflection , more rigidity ,easy maintain ,low expense and comfortable travelling crane, simultaneously large span continuous prestressed concrete continuous girder bridge construction have more and more application for the cantilever casting method, its advantages is increasingly obvious, but along with its span unceasingly increasing, the construction control request is higher, the construction control difficulty is more and more big, a series of problems in the construction control have came about. The test associate actual condition of one construction monitoring project of large span prestressed concrete continuous girder bridge with the cantilever casting method, to the construction control content, the method and the structure computation have been conducted the thorough research, and the bridge structure simulation model with the bridge structure analysis software MIDAS/Civil establishmented carries on the simulation to the entire construction stage, carries on the analysis with the forward analytic method to the construction stage. Demolition of temporary consolidation in the structure system switching process cause oversized flexibility deformation of the cantilevered end, the question which overmuch prestressed tendon in the sole plate causes that compressed stress of the sole plate oversized after prestressed Tension are conducted with the thorough research, and the optimization of the closure plan and the structure system transformation order method has solved the problems, and the test builds model to check the optimized plan at last, the checking result conforms to the standard requirement, this plan in the project application is completely reliable, feasible.