| Composite cable-stayed bridge takes full advantage of the tensile properties of steel and the compressive properties of concrete,it has a high competitive value in spanning capacity and economic performance.This kind of bridge construction process is complicated and difficult,the section parameters of the beam before and after the combination vary greatly,and it is necessary to set up construction procedures reasonably to ensure the safety and efficiency.In order to reaches the ideal design state,strictly controlling the process of construction is very necessary.In view of the above problems,the main research contents of the paper are as follows:(1)The classification of cable-stayed bridges,the structural characteristics and development history of composite cable-stayed bridges are introduced,the research background and significance are elaborated,and the research status of construction control theory is summarized.(2)The finite element model of Hongwan bridge is established by using MIDAS CIVIL.Based on the design scheme,this paper proposes three construction schemes,and selects the best one based on the safety and construction efficiency.Based on the OVM equivalent tension method principle,the scheme of “simultaneous installation of bridge deck in the process of hanging cable” is proposed,it is verified that the scheme can ensure the structural safety and the uniformity of the steel strand force.Study the impact of the crane on the structure,and optimize the crane station.(3)The principle of the unstressed state control method is explained in detail,which key point is to accurately calculate the unstressed state of the component.Two methods for calculating the unstressed cable length and the method of solving the cutting length of cables are introduced.It is concluded that the parabolic method has higher accuracy for short cables,and the catenary method is suitable for long cables.(4)Research the relationship among fabrication profile and installation profile,emphasize that the concepts of them can't be confused.Introduce the method of solving the fabrication profile and installation profile under linear and nonlinear conditions,it is concluded that the non-linear conditions have little influence on the profile calculation of theHongwan bridge.The manufacturing dimensions and the stress-free angle of the Hongwan bridge are further solved.(5)The response of several important parameters to the structural sensitivity is studied,it is concluded that the high-sensitivity structural parameters of the Hongwan bridge are the weight of the steel beam,the weight of the concrete bridge deck,the tension force and the temperature.Combining the measured data of the elevation,the parameter values of the weight of the steel beam and the weight of the concrete bridge deck are corrected by the least square method and gray theory. |
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