Performance Assessment of Modular Truss Bridge under Static Loading conditions

Abstract

Bailey bridges have an elevated position in bridge design and bridge service history with everlasting impact on current bridge design formats. With commendable service in military domain, they are an economical alternative for permanently bridging remote areas without any heavy machinery. Due to its modular nature and customization options, it is also an ideal equipment for disaster management especially for climate change affected countries like Pakistan where floods and landslides are frequent. With an estimate of hundred MBBs (Modified Bailey Bridges) presently in use in Pakistan, relevance of MBBs has only grown. With global OEMs shutting down repair support to the old vintage MBBs, a need was felt to create an indigenous variant based on Bailey design more suited to the needs of Pakistan. This can provide parts for previous MBBs and provide new sets to meet the emerging requirements. Therefore, a project titled Kash-1 was initiated by Research and Development Establishment, (RDE) and their industrial partner SD Steel, Lahore to meet these requirements. This study is project-based research that forms the backbone of this project. This is a comparative study of static loading for MBB and Kash-1 bridge (including design economization, design finalization and load testing) based on theoretical estimates and FEA models (on Ansys); validated by experiments. This study concludes performance assessment based on dead and live load deflections and discusses the comparison in detail. It also compares the research’s findings with Span/X00 deflection criteria. This study encompasses extensive literature survey of industrial standards and peer-reviewed literature spanning the time from Bailey bridge design to the present. This research contains material test reports and datasheet excerpts, pictorial records of the experimentation along with supporting data. This research opens the possibility of use of these validated 3D models as “Digital twins” as health monitoring tool of in-situ bridges by the help of inspection data.