On-Site Visualization Monitoring for Long Span Bridge on Delhi Metro Project

A new monitoring scheme, based on the concept of onsite visualization (OSV), was successfully applied for monitoring safety conditions during construction of a long span cantilever bridge in Delhi Metro Phase-II project in 2010. The bridge construction with challenging features included a 100 m long span over the Northern Railways tracks passing below, the balanced cantilever construction methodology with a see-saw condition of the pin-connected girder during segment casting processes and a horizontal curvature of the girder with 300 m radius. The light-emitting sensors with dual functions, namely sensing and simultaneous visual output of measured results, were employed in this project and played crucial roles to capture unique behaviours of the bridge under construction and to ensure safety throughout the project.