RVNL is entrusted with constructing the New Pamban Railway bridge from Mandapam to Pamban to reach Rameswaram in parallel to the old Pamban Railway bridge. The bridge consisting of 99 steel plate girder spans of 18m and one navigational lift span of 65m. The navigational span is a vertical lift span which is first of its kind in India. RVNL approached CSIR-SERC for conducting the load testing of four of the approach spans of the steel plate girder type and the vertical lift span. During the first phase of the project, as the navigation span is still to be erected, three of the approach spans of steel plate girder type were investigated for load testing during 16th to 23rd August 2024. As part of the second phase of the project, the fourth approach span on the Pamban side and the vertical lift type navigational span were investigated. Instrumentation was carried out using the LVDTs at six locations on the approach span and at 25 locations on the navigational span for the vertical displacement measurement of the bridge. Strain gage installation was carried out on all the members of the loaded side of the vertical lift span truss and also on the approach span at identified locations along the span of the bridge to evaluate the axial, bending stress and shear stresses on the bridge spans. Load testing was carried out using the using the test train formation consisting of two coupled locos with eleven fully loaded wagons. Different load cases such as static load cases by positioning the loco and wagons at predefined positions on the approach span and on the verfical lift span was carried out. Dynamic test cases were carried out for different uniform speed cases of test train running at 5kmph to 60 kmph speeds. The responses were measured using the multichannel high sensitive data acquisition system. The results evaluated are being processed to check the design limit states of the bridge spans. The bridge is crossing the sea link between Mandapam and Rameswaram, and also the highly harsh environment conditions, it was considered as a highly important bridge for the Indian Railways. Soon after commissioning of the bridge, a full fledged Real Time Structural Health Monitoring System on the vertical lift span is being implemented by CSIR-SERC .
