基于变异系数与趋势因子的斜拉桥索力评估

Condition Assessment of Stay Cable Forces Based on Variation and Trend Coefficients

摘要:

为充分应用不同时期索力监测数据提出一种基于变异系数与趋势因子的索力评估方法.该方法以索力基本评估值为初始值,赋予每一根拉索具有物理意义的权重,提出并引入两个修正系数:变异系数与趋势因子.利用斜率灰色关联度计算的变异系数反映索力监测值与目标值之间的整体变异性.利用时间序列分析计算的趋势因子,体现索力(结构)变化的趋势性,反映其安全性能.该方法简单实用,考虑因素合理充分,理论依据完备,在整个评估过程中可充分利用每一个不同时期的监测数据,评估结果不仅针对某一时间点,更加针对整个运营阶段的索力发展过程.详细阐述了该评估方法的思路与步骤,并通过宁波招宝山大桥实例证明该方法的优越性.

Abstract:

To efficiently utilize the vast measured data,a new approach is proposed for the condition assessment of stay cable forces based on the variation and trend coefficients.This method uses the basic assessment value of stay cable forces as the initial value and gives each stay cable a weight coefficient as well as other two newlyproposed significant coefficients,the variation and trend coefficients.The variation coefficient is determined by the degree of grey slope incidence,which reflects the entire difference between the measured and designed stay cable forces.The trend coefficient is obtained by the time series analysis,which reflects the developing trend of stay cable forces and structural safety.The proposed assessment method is simple and practical but with persuasive theoretical study and sufficient consideration.Every data measured in the realtime measurement can be used to give the assessment results which are not only for a stay cable condition at a time point but also for the entire inservice period.The whole idea and procedure of assessing stay cable forces are given in detail.A case study is finally conducted to show and prove the advantages of the proposed method.