Analysis And Monitoring Of Construction Scheme For Prestressed V-shaped Piers Continuous Beam Bridge

The multi-span V-shaped piers continuous beam bridge has beautiful shape,good mechanical performance,both functional and landscape attributes,which is widely used all over the world.This paper relies on a five-span prestressed V-shaped piers continuous beam bridge constructed by a bracket method.Through the construction program analysis,construction process and analysis of influencing factors,the three aspects of construction monitoring carried out research on the stress behavior of the construction process.The main research contents are as follows:The stiffness of the support system was calculated based on the measured data of the pre-compression test on site,and the finite element model reflecting the actual stress state of the structure was obtained by using the “m” method to simulate the effect of the pile and soil of the bridge.Comparing and analyzing the different demolition and closure sequence construction plans,taking the stress and deformation in the bridge construction process as the control objective,the optimal construction plan for the bridge is obtained.The above-mentioned optimal construction plan was used for finite element simulation calculation to obtain the stress and deformation of the full bridge during the construction process.The position of the upper and lower edges of the V-leg and the spans of the span were determined as the control section,and the variations of the stress and deformation with the construction phase were analyzed.The construction phase and the position of its cross section that need to be paid attention in the construction monitoring are obtained;the influence of the closing temperature and the loss of prestress on the structure are calculated,and the solid element is used to finely model the solid segment at the bottom of the V leg,and the local stress status is analyzed.The results showed that the maximum tensile stress at the bottom edge of the V leg during the construction process was 1.65 MPa,which occurred in the second stage pavement construction stage and should be focused on.Based on the analysis results of the bridge construction phase,the pre-camber of the bridge construction is calculated,and the elevation of each section is given.The monitoring section was selected and the measurement points were placed.During the construction process,deformation and stress monitoring were performed.The results show that the structural deformation and stress measured data of each control section agree well with the theoretical values.The measured maximum tensile stress is 1.48 MPa.The error between the stress monitoring theory and the measured value is within 15%,and the structure is safe during construction.The maximum errors of main beam and V-shaped piers deformation are 5.1mm and 3.4mm,respectively.The height difference of bridge closure is only 4.6mm.After the bridge is completed,the bridge surface is smooth and smooth,meeting the design requirements.The research results of this paper can provide reference for the construction and monitoring of similar bridges.