A Curved Bridge Construction Monitoring Calculations And Data Analysis

With the rapid development of economy,there is a growing demand for bridges,especially large span bridges.As a construction project carrying huge natural resources,social economic resources and technological resources,the safety and quality during the bridge construction caused people’s great attention.Since the casualties and economic loss caused by accidents during the bridge construction are serious,the specification of bridge construction mandates that the construction control should be carried out for long-span continuous beam bridge and continuous rigid frame bridge,so as the deformation,internal force and alignment of the bridge can meet the requirements of the design,and ensure the safety during the construction of the bridge.Long-span continuous rigid frame bridge is developed from continuous grid bridge and T shape frame bridge,which makes best use of their advantages and bypass their disadvantages.Due to its excellent performance in practical application,such as long span,less construction difficulty,lower cost and etc.,the continuous rigid frame bridge becomes the first candidate in prestressed concrete bridges.Many researches on construction control of continuous rigid frame bridges are focus on straight bridges,whereas the case of curved bridges is rare.However,with the development of traffic construction,the application of long span curved bridge is increasing gradually.Compared to the straight bridge,the construction control of curved bridge concerns not only the monitoring of the vertical elevation,but also that of the horizontal displacement.The monitoring of the internal force shall consider the effect of horizontal bending moment.Therefore,the construction control of a curved bridge brings a greater challenges.In this paper,a long-span prestressed concrete continuous rigid frame bridge is studied,the whole process and the method of construction control are discussed.Finite element analysis software MIDAS/CIVIL is used to establish the finite element model of the curved bridge,the construction process is simulated,the camber,cumulative deflection and internal stress during the cantilever construction of the beam are obtained,the simulation results are using as the theoretical basis in construction control.In the process of the construction control,the problem of the asymmetry of the section stress is studied.In the construction process,the elevation,temperature and stress of the monitoring points on the corresponding section are measured.By comparing the measured data and the simulation results,the accuracy and safety of bridge construction process are judged and ensured.In the end,a reasonable closure scheme is proposed according to the simulation model and measured data,and the closure of curved bridge is successfully completed.The results showed that:(1)compared with the straight bridge,the deformation monitoring of the curved bridge includes not only the elevation,but also the horizontal displacement;(2)internal force monitoring of a curved bridge should consider not only the upwards and downwards monitoring points to verify the vertical bending effect,but also the left and right monitoring points to verify the horizontal bending effect.Because the existence of the horizontal bending moment,the stress on the section of a curved bridge are distributed asymmetrically,the asymmetric distribution can be used to inspect the bend effect during the construction of the curved bridge;(3)finite element model of the curved bridge proposed in this paper accurately simulated the stress and deformation during the construction of the bridge;the control method ensured the safety of construction process of the curved bridge;the bridge alignment and stress state meets the design requirements;the paper can provide a reference for the construction control of a curved continuous rigid frame bridge.