Analysis Of Construction Error Propagation Characteristics Of Multispan Cable-Stayed Bridges

The construction of multispan cable-stayed bridge is a complicated process, during which the bridges will inevitably be affected by lots of factors, and thus lead to the formation of error of structural parameter, beam alignment and internal force. If construction error is not efficiently controlled and restricted, the target alignment and internal force state won’t be reached. As the engineering background of this paper, JiaoShao bridge adopts geometry control method during construction and the control objective is the alignment of main beam. This paper aims at the research of characteristics of main beam alignment error of multispan cable-stayed bridge under geometry control method. The main contents are as follow:1. The parametres which influence beam alignment most can be worked out by analysis of parametres sensitivity and three typical parametres are selected here,which are geometry parametre, rigidity parametre and load parametre. Some conclusions can be drawed after calculation and analysis:girder manufacturing length, cable elastic modulus and girder weight are sensitive parametres to beam alignment at complete stage; girder manufacturing angle, cable manufacturing length are less sensitive parametres to beam alignment at complete stage.It’s convinent to draw conclusion that the error of geometry parametre will cause greater effects on beam alignment in finished state and thus illustrate that manufacturing accuracy of elements should be well controlled at manufacturing state.2. When it occurs to the error of girder manufacturing length, girder weight, manufacturing angle, formation, variation and propagation of beam alignment error are discussed. The analysis shows that:the error of beam alignment appears to be large and remains stable form beginning of construction to finished state in case of the error of girder manufacturing length; while the error of beam alignment caused by the error of manufacturing angle is remarkable at beginning but becomes less and less along with the construction of follow-up girders and is not remarkable at complete stage.