Vibration-Based Condition Assessment and Retrofitting of the Chambal Railway Bridge in India

Abstract

In recent times, there has been a growing interest among researchers in vibration-based damage detection methodologies, given their attractive features and the potential to offer continuous health monitoring at a reasonable cost. This study focuses on assessing the extent of damage in a pier of the Chambal Bridge, situated on the Chambal River in the Bhind-Etawah section of the North Central Indian Railways. The investigation was prompted by the observation of visible cracks in the bridge pier, causing disruptions to regular passenger and goods train services. Conventional nondestructive tests were ineffective in gauging the extent of damage, leading to the necessity of vibration-based condition assessment. An ambient vibration test was conducted to extract the modal properties of undamaged and damaged piers. Changes in frequency were utilized to estimate stiffness loss, while differences in mode shapes were employed to pinpoint the locations of damage. The findings revealed significant stiffness degradation, prompting the development of a retrofitting plan. A detailed finite element analysis guided the design of a reinforced concrete jacket with additional reinforcements to restore the damaged pier’s original strength and stiffness, which eventually facilitated the safe resumption of train services. Bridge infrastructures are crucial for a nation’s economy and growth. Thus, their deterioration can have severe economic impacts, increasing public safety risks and potentially leading to loss of life. Ensuring the safety and structural integrity of bridges is therefore essential, and researchers have increasingly focused on vibration-based health monitoring techniques for assessing bridge structures. This study focuses on rehabilitating a pier of the Chambal Bridge, located on the Chambal River in the Bhind-Etawah section of the North Central Indian Railway, by detecting damage through vibration test data and subsequently designing a reinforced concrete jacket for retrofitting using finite element analysis. After implementing the proposed retrofitting scheme and passing safety inspections, trains resumed normal operational speed over the bridge, demonstrating the investigation’s success and the effectiveness of the proposed solution. When trains resumed operation over the retrofitted bridge, the news was published in a leading Indian daily, The Times of India (Sharma 2016), highlighting the importance of it to the community. By employing vibration-based testing techniques and advanced finite element analysis, this research addresses the challenges of deteriorating bridge infrastructure and feasible practical solutions as remedies, ultimately enhancing public safety and preserving essential transportation assets.