Research On The Construction Monitoring Technology Of Long-span Prestressed Concrete Continuous Rigid Frame Bridge

Since the 21st century,the traffic engineering is booming at an unprecedented speed.As an important ingredient of the transportation hinge,bridge structure played an important role in the process of traffic engineering prosperity.With appearance of new material,new technology and new design,a batch of new type bridge structure have sprung up.Among them,the prestressed concrete continuous rigid frame bridge with its good structural performance,strong seismic capacity,comfort travel,simple maintenance,beautiful appearance become one of competitive bridge type in our country.Continuous rigid frame bridge usually take cast-in-place cantilever method.In the construction process,the bridge structure is influenced by many factors.This method makes the stress and displacement variation of the bridge very complicated.Therefore,in order to ensure the construction safety of continuous rigid frame bridge and the quality of the bridge,a further study on the construction monitoring has theoretical and engineering application significance.The main content of this article: to summarize the existing situation,development and the characteristics of structure and mechanical of prestressed concrete continuous rigid frame bridge construction at home and abroad;to further study control method and the structure calculation method of the continuous rigid frame bridge construction;according to the construction control of long-span prestressed concrete continuous rigid frame bridge,to study the shear lag;combining the engineering example of No.2 bridge of river Qi in Huanggang,to research alignment and stress monitoring technology from the measuring principle,the setting of observation point,measuring method and so on;by the mean of structural finite element software,Midas Civil,to calculate bridge camber and stress data at each case,as the reference of bridge construction;using Midas FEA,to modeling analyze the box beam shear lag,research the influencing factors and combined with the stress data in the bridge of actual engineering,research shear lag of continuous rigid frame bridge;based on the principle and method of construction monitoring,to analyze construction monitoring error and put the corresponding solution;to supplement related research and improve previous monitoring theory,as a reference for future similar bridge construction control.The main innovation point of this article: in respect of monitoring of bridge alignment,to seriously analyze bridge camber and according to the actual project,to list displacement data of each case when the bridge applied camber;to overfit function formula between strain and frequency on the basis of the work principle of steel string sensor and put forward dynamic extraction method of elastic modulus according to age of concrete for improving the stress monitoring accuracy;in the light of the structural finite element simulation data and actual control data,to analysis box girder shear lag,and ensure that the construction process and the bridge structure internal force are in the range of security,and the alignment is within the scope of permissible error when the whole bridge is completion.