Research On Hoisting Optimization And Cable Force Calculation For Long-span Concrete Arch Bridge

Since the 21st century,as the cable hoisting emerges and develops,the new method is widely used in building long-span concrete arch bridge.Also with the bridge field's rapid development,the span of arch bridge is constantly making new history.Niu Lu River Bridge,the bearing reinforced concrete arch bridge with the net cross 195m,the main arch of which is lifted with the overall cross-section prefabrication,is the largest span arch bridge among the same types of bridge using this hoisting method.In this paper,We will take the Niu Lu River Bridge to study,and the main content is as followed:(1)This paper made detailed descriptions on the construction process and the designs of the Niu Lu River Bridge's original hoisting scheme and optimized hoisting scheme.The original hoisting scheme was examined through the check of the arch rib strength and lateral stability in the hoisting process.The optimized hoisting scheme was examined through the check of the strength and lateral stability in the hoisting process,the check of"strength-stability"of the overall operation condition after folding process,and the check of"strength-stability" of the main arch and vertical stiffness in the working process.(2)Through the comparison and analysis of two kinds of hoisting scheme,we summarized their advantages and disadvantages in structural safety,environmental protection and construction period.(3)This paper introduced different traditional calculation methods of the cable force in the process of hoisting.Through the finite element software Midas Civil and BRanalysis,we calculated each buckle's initial pull force by the elastic-rigid support method,the zero displacement method and the moment balance method,and also we compared and analyzed the strengths and weaknesses of those methods.(4)In order to solve the problem of localized tensile stress in the traditional calculation method,we found the optimal force after the optimized calculation of the cable force by the influence matrix method based on the unknown load factor of Midas Civil platform.(5)Through the optimized analysis method,we calculated the precondition of each deduction points of the Niu Lu River Bridge in each construction stage.