Condition assessment of long span cable-stayed bridge

Abstract

A condition assessment model for cable-stayed bridge was proposed, and a cable tension, elevation and frequency condition assessment model was then applied. With the optimized cable tensions as criterion, upper and lower bounds were then introduced. With the elevation of bridge completion as benchmark, and with the allowable vertical displacement of control points to interpolate to generate the upper and lower bounds of elevation, algorithm of condition assessment was programmed. Using moderate index model to interpolate linearly, and with the application of variable weight synthesizing principle (VWSP) and correlation of slope coefficient, according to a set of inspection and monitoring data, performance condition of cable tension, elevation and frequency were calculated. Results showed that with the decrease of balanced coefficient α, the assessment result is a process of degradation. The more divergent the variable weight is, the more severe is the degradation of the bridge component, and the larger is the curvature of curve α-V. Eventually, the model predicted that, for those bridge components whose grade of single survey point is exactly the same, the curvature of curve α-V is constant zero, i.e. there is no correlation between the assessment result and the balanced coefficient α. Numerical simulation showed that it agrees quite well with the expectation.