Research On Construction Monitoring Of ChaiBu Bridge

Due to the wide driving vis ion and reasonable stress system of single cable box girder,it has been widely used in recent years.Because the cable-stayed bridge is a statically indeterminate structure,the spatial effect of wide box girder is more significant with a new type front fulcrum hanging basket,geometric nonlinearity has a great influence on it,the difficulties of construction were also increased.In order to ensure the quality of construction of bridges,through strict control of key technologies,timely identification and error correction in the construction process to ensure that the internal forces and linear match the bridge design well is necessary.In this paper,the chaibu bridge is used as the research object,the key technologies of construction monitoring system for prestressed concrete cable-stayed bridge are studied systematically,and the main content are as follows:1)Based on the domestic and foreign research results of construction monitoring and the actual engineering projects,combined with the engineering background of the chaibu bridge,determine the construction monitoring implementation scheme and the overall monitoring princ iples and methods for the construction of the bridge.Clear the key parameter monitoring method of each construction phase;2)The stress and deformation of the front fulcrum cradle is analyzed with us ing the traditional theory of force calculation,furthermore,simulate the deformation during the process of construction of the front fulcrum cradle by using the beam element of midas;3)Finite element analysis model is established,make a construction simulation calculation to check the use of the limit state of cable stayed bridge in accordance with the specification requirements and obtain reasonable and ideal bridge construction parameters :stress(strain)monitoring,tension of cable tension in construction stage and so on;4)The control of construction stage deformation parameters,the main content are as follows: each construction segment construction and the deformation calculation of preceding fulcrum traveling carriage,deviation monitoring of main tower of cable stayed bridge,the analysis of shear lag effect.The research results show that using the front fulcrum cradle,the cradle has a larger transverse deformation during the construction process of single plane cable stayed bridge with wide box girder;the greatest shear lag effect of wide box girder is in the second segment,take reasonable and effective measures to deal with the key structure in the construction process;the theoretic form of deformation monitoring method for bridge construction process is in agreement with the actual form,it can be better uesd in instruct on-site construction.