Researchs On Some Questions Of Construction Control Of Continuous Prestressed Concrete Bridge

Along with the augment of bridge span,construction control became more vital. The bridge of construction control includes the line shape controlling and the internal force control.Line shape controlling is to control every segment's vertical deflection and lateral displacement strictly to ensure the finished line shape approaches the designing line shape;The internal force control is to control the stress in the course of construction and after the bridge finished,especially during joining the two sections of the bridge,making it not to be too large and unsafe and satisfy the designing requirement.In order to establish an easy and feasible construction method,this paper took a certain bridge construction project in Hangzhou Shida road as the example to study bridge construction control of long span continuous prestressed concrete bridges.This paper use structure analysis software,Doctor Bridge,in the simulation of the bridge construction process for change the value calculated parameter to modify the influences of parameter error to the deflection and stress of bridges.Analysis the result of control and index its limitations identification and then carrying on construction control with Gray Theory.At the same time,the use of Gray Theory in long span continuous prestressed concrete bridge construction control was studied in this paper and calculated program about the Gray Theory used in this thesis was worked out by excel.Figured out gray model in order to predict deflection changes during segments construction,then can utilize these predicted values to work out the elevation of moulding board.According to the final close results of Hangzhou Shida road continuous prestressed concrete bridge,four close segments' close elevation precision meet the designing requirement,and the maximum elevation discrepancy is 11 millimetre.The line shape of main bridge is relatively smooth after closing up.Comparing with the design line shape,the actual line shape of box gorder's number value varies from inosculating to exceeding about 2cm gradually.And from stress analysis of box beam,the main bridge is in safe state all the time during construction.So Hangzhou Shida speed way continuous prestressed concrete bridge's construction control achieves its purpose.Lastly,the deficiencies in this paper and further study of construction control were listed.