Cavendish Road Underbridge
FEA Software: LUSAS Bridge Plus, Non-Linear
CASE STUDY
The structure is a single span metallic half through underbridge comprising five decks. It carries 3No. tracks of the Balham to Beckenham Junction (BBJ) line over the end of Cavendish Road and the beginning of a footpath leading to Tooting Bec Common.
The structural assessment has been undertaken in accordance with the Form AA and Network Rail Guidance Note NR/GN/CIV/025, ‘The Structural Assessment of Underbridges’ and the Inspection for Assessment.
Non-linear Analysis was undertaken to reflect the non-linear nature of the geometry, material and contact and, for verification of EVBA. The non-linear analysis also examines the potential existing deformation which is not measurable in practice. Such deformations are referred to as initial imperfections.
CONCLUSION
The conclusion from the LSA, EVBA and Non-linear analysis is that the load capacity of the Deck 5 structure is RA15 (minimum 25 BS unit). NR/GN/CIV/025 assessment philosophy is based on plastic global analysis theorem.
existing deformation which is not measurable in practice. Such deformations are referred to as initial imperfections.