Optimization Of Hoisting Scheme And Force Analysis Of Cable System For Long-span Reinforced Concrete Arch Bridge

Since the 21st century,along with the continuous development of material production technology and mechanical manufacturing technology,the cable hoisting construction process has been significantly improved,resulting in the application of this method in large-span reinforced concrete arch bridges.When constructing a long-span arch bridge by cable hoisting construction method,how to choose a suitable hoisting construction plan and how to ensure the safety of the entire cable hoist system have become an important issue to be solved in the construction process.This thesis took Niu Lu River Bridge of the Zhanghua high-speed connection line as the engineering background,and studied the optimization of the bridge rib hoisting scheme and analyzed the force of the cable hoisting system under the preferred scheme.The main research contents are as follows:1.The main arch ring of Niu Lu River Bridge is hoisted by cable.Two different hoisting schemes were proposed for this method——horizontal detached hoisting of arch ribs and integral hoisting of arch ribs.Firstly,the two alternatives were explained in detail,and the construction phase was divided according to the construction process under different schemes.Then establish a finite element model and use elastic-rigid strut method to calculate a reasonable set of initial pull of the buckle.Next,according to the initial pulling force of the buckle,the arch rib was analyzed for the formal assembly,and the upper and lower edge stresses of the arch rib section were calculated at each construction stage.At the same time,Calculate the cumulative displacement of the arch ribs after the elosure of the dragon by the formal analysis,and solve the arch ribs.Finally,taking into account the effects of wind loads,calculated the lateral stability of the arch ribs during construction.2.Based on the basic principle of Analytic Hierarchy Process,this thesis cortstructed a Analytic Hierarchy model for arch rib hoisting construction scheme based on five factors:section stress,structural stability,closure line shape,construction cost and construction period.Taking the Niu Lu River Bridge as an example,according to the Analytic Hierarchy model,contrast two arch rib construction schemes——horizontal detached hoisting of arch ribs and integral hoisting of arch ribs.It was concluded that the integral hoisting of arch ribs in this project is a better solution.3.Calculate the force of the cable hoist system when constructing with a better solution.The calculation includes:Calculate the cable force of the main cable,the working cable and the buckle,and check the corresponding safety factor;Analyze the stress of the main tower and the detent tower,and check the strength and stability;Calculate the stress of the main tower anchor and the buckle anchor,and check the stability of each anchor and the shear resistance of the anchor pile.