MEMS-ENABLED VIBRATION MONITORING AND DIAGNOSTIC EVALUATION FOR LONG-TERM HEALTH ASSESSMENT OF SWARNAMUKHI AND BHAKTA KANNAPPA SETHU BRIDGES IN SRIKALAHASTI

This study presents a year-long vibration-based structural health monitoring (SHM) of the Swarnamukhi River Bridge and Bhakta Kannappa Sethu Bridge using a MEMS accelerometer integrated with a lowcost microcontroller system. The monthly dynamic response parameters of acceleration, displacement, frequency, and velocity were monitored from June 2024 to May 2025 under four traffic loads (Low to Peak). Advanced diagnostic indices including Normalized Dynamic Index (NDI), Dynamic Performance Ratio (DPR), Stiffness Degradation Index (SDI), and Health Stability Index (HSI) were computed to assess real-time structural integrity. Results revealed Bhakta Kannappa exhibited higher dynamic variability, with peak displacement and velocity reaching 1.418 mm and 0.03742 m/s. In contrast, Swarnamukhi exhibited higher stiffness and frequency stability, with peak values of 0.02931 m/s and 1.088 mm, respectively. Swarnamukhi's greater stability up to 358.00 was supported by HSI values, but Bhakta Kannappa's lower HSI (< 50) indicated wider reaction variations. Seasonal diagnostic trends have documented the effects of heat and stress accumulation caused by traffic. In situations where resources are limited, the combination of inexpensive MEMS (Micro-Electro-Mehanical Systems) sensors and diagnostic indices offers a potent foundation for continuous SHM, facilitating predictive maintenance and enhancing bridge resilience.