Determination method for metal bridge superstructure replacement priority using strength, economic and operational criteria

Abstract

The article describes the problem arising from the setting trains with increased axleloads into operation on bridges with superstructures, engineered according to the old design standards. On the railways used riveted metal bridge superstructures, which require replacement due to significant corrosion, mechanical and fatigue damage, due to insufficient carrying load and residual fatigue life to pass the prospective load. Superstructures, designed in the 30s-40s, are more than 80-90 years used in conditions of a relatively difficult operation. During long-term operation, processes occur in elements and joints that lead to the formation and development of various hazard degrees damages, and failures. It is necessary to resolve the further exploitation issue of old bridge superstructures and their replacement. The author has applied the analyzing method of the criteria system, with the account of economic and technical capabilities for replacement priority determination of bridge superstructures. A set of criteria were proposed for solving this problem in digital form. Compiled matrices of pair-wise comparison, the comparison was performed using a relative importance scale with the test significance determination. By the linear algebra methods the eigenvector of matrix components values — local priorities — are calculated for each pair-wise comparisons matrix. As a result of calculations by the proposed criteria, were obtained global priorities for replacing options for riveted metal superstructures made by old design standards. The mathematical apparatus of the criteria hierarchy method is easy to use and allows you to get a solution in digital form, you can use other criteria.