Research On Cantilever Casting Construction Key Technology And Control Method Of Continuous Girder Bridge

In recent years, with the rapid development of China's transportation infrastructure and increasing bridge span, prestressed concrete continuous girder bridge has been widely used in bridge construction, cantilever casting construction has become the main method of construction of the modern building long-span bridges. Considering cantilever construction continuous beam bridge will go through a complex construction process, during the process we should not only ensure the progress and quality of the bridge construction, but also ensure the dynamic changes in the structure of the bridge to meet later linear and stress requirements, so it is necessary for continuous girder cantilever to study sasting construction of bridge construction of key technologies and control methods.In this paper,based on Su Yang highway Baita River Bridge, at first it studied the continuous bridge cantilever cast during the temporary consolidation techniques, technology and construction technology to expand the collapsed section cradle construction research. From the point of view of bridge construction process, this paper introduces the temporary pier beam consolidation arrangement, then for the consolidation of temporary pier top performance mode check the pressure compression performance finishing rebar, concrete buttress anchorage length to ensure the stability of the construction process. Thereafter thesis pouring each cantilever beams used in the process of analyzing the cradle selection mechanisms and structures constructed using Midas/Civil establish the force performance cradle beam finite element model, the bottom of the basket and boom. Then it introduced a hanging basket preloading static load test and draw cradle elastic deformation profiles are calculated camber construction late to prepare; at last this paper folding segment temporary consolidation, temperature and collapse collapsed construction construction breeding to start on. Construction technology on three important time course covers the full cycle bridge construction, bridge construction to ensure the quality and progress of the foundation.Construction technology combined cantilever situ continuous beam bridge features herein are choosing dress analysis of the construction process Baita River bridge main bridge analysis. After determining the finite element model of the design parameters values, calculated after the design loads, boundary conditions and simulation division of construction conditions, we use MIDAS/Civil to establish a finite element model of the bridge, the chapter then carried out Baita River main bridge construction process simulation analysis, forecasting and analysis of bridge construction bridge stress and deformation.Then in the construction process simulation based on finite element analysis, for continuous beam bridge construction control process parameters this paper studied controlled sensitivity analysis,it studied during the process of building a bridge to the larger structural perturbation factors, in order to control the construction of theoretical models and real-time correction feedback control. The results show that the weight of the load and prestressed concrete bridge structural load deviation deflection and stress in the structure of the construction phase and into the final stage of greater impact, sensitivity elastic modulus of concrete and ambient humidity is relatively weak. Since the temperature there are also some influence on the stress and deformation of concrete structures,this paper summarizes the temperature distribution in the form of a conventional concrete structure on the basis of the proposed system and the temperature difference between the temperature difference between the two temperatures gradient effect forms, introduced the mechanism inside the concrete temperature loads produce two temperature stress, and analysis of two temperature differences in the role of a bridge construction stage impact and bridge phase Alignment and stress for bridge construction control considering temperature effects provide a theoretical basis.Based on finite element simulation and parameter sensitivity analysis,I chose to build adaptive control law Baita River Bridge construction control system, and the specific implementation of Baita River Bridge linear stress control and monitoring. This article describes the linear control of the formwork elevation setting principle, full-bridge elevation observation network arrangement methods and measuring methods, and the use of gray system theory GM (1,1) model deck elevation difference between the ideal state and the actual state as ash differential sequence modeling, forecasting the ideal state and the actual state of the construction phase deviation to be corrected and formwork elevation last Baita River bridge collapsed smooth, linear smooth, gray theory proved highly efficient and practical in bridge construction control. Then this paper introduces the monitoring stress strain gage selection and working principle, arrangements and monitoring methods stress measuring point monitoring network, the stress monitoring results show that the measured stress and stress theory is consistent regularity and little error after the adaptive control parameter correction and error correction, a higher state structure theory and construction of the actual state of the degree of similarity.In situ cantilever bridge construction and construction control key processes specific implementation process, many times "temperature effect" figure, visible temperature has a significant impact on bridge construction and control, it is necessary to study the temperature effects of bridge construction control. In summing up the past, the temperature distribution in the form of concrete structures on the basis of the proposed system and the temperature difference between the temperature gradient of the temperature difference between the two forms of action, describes the mechanism inside the concrete temperature loads produce two temperature stress, and then analyzes the role of the temperature difference between the two bridges in the construction phase bridge and into linear stages and stress, provide a theoretical basis for the bridge construction control considering thermal effect.