Study On Construction Controlling Technology Of Hybrid Beam Cable-stayed Bridge

The cable-stay bridge is a commonly used bridge type in modern large span bridges. The structure system is affected by construction process because of its high degrees and obvious space effect. It is an important scientific and technological work to make structure to be finally satisfied to designing internal force and booked line form by adjusting cable tension and girder assembled elevation. In our country, the construction monitoring and control technology is still on at stage of exploring. Parameter identification, monitoring technology and control system are waiting to be further investigated. Taking Rong hu bridge project as the background, the paper Studies on the optimization of dead load cable tension, construct system of controlling, effect of non-linear factor, limit bearing capacity of structure and spatial stress of concrete-filled steel tubular tower and the combination of girder, which are based on the hybrid cable-stayed bridge.Asking for the maximal deformation of tower and girder to be minimized and cable permissible stress as constraint conditions, the paper tries to solve the ideal dead load cable tension by combining finite element calculation and optimize analysis. It indicates that this method is reasonable and feasible through optimization of dead load cable tension of Rong hu bridge. Secondly, it offers the theoretical foundation for many times tension method of "divided each tension and put in place progressively" by asking for influenced matrix method to optimize constructed cable tension.Based on the application of grey forecasting control theory on the hybrid d cable-stayed bridge, the paper puts forward construct control system of the hybrid cable-stay bridge by cantilever assemble construction. This control system is based on the constructing forecasting control of the hybrid cable-stayed bridge, with continual renovation of model's parameters, output feedback in model correct and rolling to optimize actually, in order to meet the constant change of the systematic behavior, the environment and noise in the construction course, in addition, also compensating immediately the mismatch of the model. The project practice indicates that the control system has stronger adaptability.The paper deduces tangent stiffness matrix and set up geometrical nonlinear model of construction control calculation of the cable-stayed bridge. On this basis, it is studied that the non-linear factors of geometry influence construct control of the hybridcable-stay bridge, and pointing out every non-linear factor's influencing degree of the cable-stay bridge in different constructing stages.Probing into two kinds of questions of stabilizing of wide cable-stay bridge with single tower and single cable plane, according to the energy principle, the paper proposes simplifying computing method about the stability of bridge tower, and analyses the stability of a real bridge.Analyzing and monitoring spatial stress of concrete-filled steel tubular tower in the whole construct course. Through analyzing of stress of the concrete-filled steel tubular tower, the paper has explored the changing law of tower's stress at different constructing stages, and pointed out tower structure stress concentrated area, summarized the method about the performance appreciation on concrete-filled steel tubular tower. Based on Rong hu bridge, to study seriously the spatial stress of the conjoint of steel and concrete girder, to analyze the stress changing course of different material and different position, to point out the position where stress is centralized and crack is easy to appear. The studying results offer a scientific basis for design, construct and improvement of the similar structure.