Retrieved from Iss. 117, P. 2, 2025
Pages 297 -311
Received 23.01.2025
Revised 27.05.2025
Accepted 24.06.2025
Retrieved from Iss. 117, P. 2, 2025
Pages 297 -311
Abstract
The article presents research results focused on evaluating the technical condition of road bridges using impulse testing as part of modal control. Theoretical principles and practical aspects of applying impulse loading are considered. Such loading is produced by a short-time dynamic impact on the span structure. An example of field testing of a large bridge is described, where free vibrations were excited by dropping a load onto the roadway. The vibration response was recorded with seismic sensors, and the signals were processed using a spectral analysis program. The obtained results made it possible to identify natural frequencies, damping decrements, and mode shape ordinates. They were also compared with finite element models. A decrease in natural frequencies compared to previous tests was observed, which indicates a reduction of the integral stiffness of the span structure. According to DSTU 9181:2022 Guidelines for assessment and forecasting of the technical condition of road bridges, the technical state of the structure was preliminarily evaluated as level 4 – “limited serviceable.” The findings confirm the relevance and usefulness of impulse testing for quickly obtaining dynamic characteristics of bridges, identifying stiffness reduction trends, and improving the assessment of the technical condition of structures
Keywords:
highway, natural vibration modes, defect, dynamic testing, stiffness, bridge, modal control, parameter, span structure, technical condition