Construction Control Research Of Double Towers And Single Central Cable Plane Extrodosed Cable-stayed Bridge Based On The Least Square Method

With the rapid development of the bridge construction, many new bridge types have been produced constantly. The extradosed cable-stayed bridge is a typical combined structure of continuous girder(rigid frame) bridge and cable-stayed bridge in the development of bridge, and it displays more and more enormous development potentiality especially in large and medium-sized bridge. Presently, cantilever construction is the main method in the extradosed cable-stayed bridge construction, and the structural linear and stress is easily affected by environment and structural change in the construction, which may lead to the generation of errors. As the extradosed cable-stayed bridge has not more than ten years developmental history in China, its design mainly refer to the theory of the existing cable-stayed bridge, and the construction control system has not yet been standardized. So it’s really necessary to do construction control research of extrodosed cable-stayed bridge.Combined with the construction of a double towers and single central cable plane extrodosed cable-stayed bridge which span is 60+110+60 m, this thesis is mainly focus on construction control research of extrodosed cable-stayed bridge based on the least square method. Firstly, it expatiated the principle and method in construction control based on the characters of extrodosed cable-stayed bridge. A finite element model was established, and the stress and deformation of the structure was calculated and analyzed in each construction stage by means of construction process analog simulation. On the basis, this thesis studied on parameter identification of sensitive parameters, and identified the sensitive parameters and insensitive parameters of double towers and single central cable plane extrodosed cable-stayed bridge. Then it corrected the design parameters in the analog simulation with the measured data of construction based on the least square method, and the simulated results of the computations was compared with the forecasted displacem-ent value based on grey-forecasting model.The final result shows that grey prediction can play an auxiliary role in construction control, but its result is very depend on the development trend of and can easily affected by the accuracy of the data. And least squares method is adapted well to construction control of double towers and single central cable plane extrodosed cable-stayed bridge, it could make the analog simulation more accurate than grey prediction model by correcting the sensitive parameters. The bridge almost achieved the target state by construction control based on parameters correction, and the measured values and the target value is very close after cable force adjustment. Therefore, the least squares method is proved to be very applicable and accurate in double towers and single central cable plane extrodosed cable-stayed bridge construction control.