Multivariate Statistical Sensitivity Analysis for Construction Control of Long-span Cable-stayed Bridges

In order to master the influence law of structural parameter variation on structure state of long-span cable-stayed bridge, ensure the construction safety and engineering quality of cable-stayed bridge, according to the practical requirements of parameter sensitivity analysis in composite/hybrid beam cable-stayed bridges construction control, random multi-parameter sensitivity analysis in the construction control process is realized by considering the variability of the different structural parameters and the same parameters in different structural positions. From the view of statistics, parameter sensitivity analysis can be defined as a marginal distribution problem, introducing the experiment design method into the random multi-parameter sensitivity analysis and evaluate the sensitivity of the parameters through parameter significance test. Introduce the substructure method into the random parameter sensitivity analysis, group components manufactured or constructed in the same batch or under similar conditions into the same substructure, the same parameters within the substructure are treated as a random variable, which improves the computational efficiency and reduces the number of random variables. Grouping experiment design is adopted to reduce the difficulty of uniform experiment design, all significant parameters are gathered together for the overall parameter significance test after grouping parameter significance test, finally, determine the sensitive parameters of the structural response. Take the construction control of a composite/mixed beam cable-stayed bridge across the Yangtze River as an example, 19 structural responses and 63 structural parameters were determined to demonstrate the efficacy of the proposed algorithm for the multi-parameters sensitivity analysis of the bridge. The result shows that the alignment and internal force of the composite main beam are sensitive to the cable force, the weight of bridge decks and steel beam. The response of the main beam is related not only to the variation of parameters but also to the relative position of structural parameters and response sections. In general, the influence of substructural parameters near the response section is greater than that far away from it. © 2021, Editorial Department of China Journal of Highway and Transport. All right reserved.