The Research On Long-span Low Pier Rigid Frame Birdge Construction Control And BIM Application In Construction Stage

Construction control is an essential link throughout the whole process for long-span bridge cunstruction.The main pier of low pier rigid frame bridge is short and its height span ratio is usually less than 0.1.Hanging basket of cantilever construction is generally adopted in low pier long-span rigid frame bridge.While,the corresponding studies are insufficient and most of them focus on the calculation of stress monitoring and linear control.Monitoring information visualization and feedback control in the construction process has not been deeply explored.In recent years,BIM technology has been developing quickly in Chinese transportation industry.BIM is used in this paper to provide an application platform for the visualization and dynamic control of monitoring information in the construction process of long-span low pier rigid frame bridge,which is of great significance in ensuring structural safety and improving construction quality.Based on the objectives of stress safety monitoring and line quality control in the construction process of low pier rigid frame bridge,this paper studies its control content,BIM modeling by programming and application of collaborative management platform in cantilever stage and closure stage.The application mode of BIM in the construction control of low pier rigid frame bridge is constructed upon the project to analyze the feasibility in visualization of control information and test the effects in construction safety and quality.Based on the engineering case of Tanjiang super bridge of Kaichun expressway in Guangdong Province,this paper studies the control process in each stage of superstructure cantilever construction and the practical effects of BIM application mode on safety and quality.The application steps and results are as follows:(1)Take Tanjiang super bridge as an example and build the finite element model of the whole bridge by Midas civil.The stress value of key section and the camber of each girder in all stages of the bridge are calculated.The theoretical alignment of the main bridge can be obtained.Complete the monitoring of hanging basket preloading test and deformation monitoring during construction,which reduced the impact of its elastic deformation on the main bridge alignment;(2)Constructe the application mode of BIM in the construction control of low pier rigid frame bridge,establishe BIM and monitoring organizations and use Revit and Dynamo to finish the 3D information modelof the whole bridge;import the model into the platformand the construction control information visualization and feedback regulation are carried out from two aspects—stress monitoring and linear control;(3)Monitor the changes of stress and elevation in the process of cantilever stage.Based on the BIM collaborative management platform,the feedback and adjustment provide accurate basis for the regulation of subsequent beam sections.The application results show that the application mode of BIM construction control has significant effects on information transmission,safety monitoring and alignment control;(4)Refine the calculation of closure counterweight and jacking force in the construction,monitor the changes of stress and elevation in the process of closure and studied the jacking effect.The application results show that the application mode of BIM construction control can visually display the elevation and stress information of the whole bridge during the construction process in closure stage of low pier rigid frame bridge construction,which effectively improves the safety and quality of counterweight and jacking closure.