Iterative Calculation for Parameters Error Correction in Unloaded State of Suspension Bridge Based on Principle of Closeness
A parameter error correction closed iteration algorithm is proposed to address the problem of non-closure in the error correction algorithm for the unstressed length and constant load weight parameters of the main cable installation in the unloaded state of suspension bridges.A nonlinear equation system at the cable saddle is established based on the theory of catenary equations,and an iterative equation system among each suspension rod is established based on the theory of segmented elastic catenary.The nonlinear equation system and iterative equation system are combined by geometric compatibility conditions to iteratively solve the mechanical parameters of each span of the main cable.By utilizing the mechanical equilibrium conditions of the main cables on both sides of the cable saddle,the iterative correction calculations of each cable saddle position in the entire bridge are carried out sequentially until the cable saddle and the main cable system of the entire bridge meet the convergence conditions,thereby achieving a reasonable bridge completion state for the suspension bridge.The key control parameters during the construction period of the suspension bridge and reasonable calculation parameters for the completed bridge state are used to realize closed iteration calculation.Finally,based on the reasonable bridge state parameters,the stress free length of the suspension rod in the empty cable state,the installation position of the cable clamp and the reasonable tension of the anchor span are solved to achieve closed iteration calculation of error correction for the empty cable state parameters.The result shows that the iterative algorithm is applied to actual suspension bridge engineering,and the maximum difference between the main beam shape and the design target value in the completed bridge state is measured to be 5.8 cm.The deviation of the cable pylon in the completed bridge is controlled within 1.0 cm.The overall error rate between the calculated and measured tension values of the anchor span cable strands is controlled at around 1.0%.The monitoring results of key technical parameters in the completed bridge state meet the requirements of the design and specifications.The effectiveness and feasibility of the research method in this study is verified.with the comparative analysis,between the iterative calculation method for the cable state of a suspension bridge that satisfies the closure condition and the computational theory of literature algorithms.The derived main cable shape finding iterative algorithm can provide certain reference value for the calculation theory of design and construction stages of suspension bridge.
bridge engineeringerror correctioniterative calculation on principle of closenessunloaded state of suspension bridgereasonable completed bridge state
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