Rail Structure Interaction (RSI) Validation for Bridge No. 175 – Navadgi (South Central Railway – India)
Overview of the Structure:
This bridge is constructed on the river with pre-stressed concrete ‘I’ Girder supported on circular pier. The overall length of bridge is 81.00 m comprising 4 spans of each 20.00 m.
Scope of Work:
The scope of work includes finding out the following parameters. Maximum horizontal displacement of the deck due to longitudinal loads. Relative displacement between rail and deck due to longitudinal loads. Additional tensile and compressive stresses in rails due to thermal loads in summer. Finding out the Maximum displacement in the deck due to rotation. Maximum vertical displacement of the deck at ends. Numerical Modelling and analysis. Generation of Finite element model using MIDAS.
Rail structure interaction study is carried out to workout forces induced on rails, bridge components due to interaction effects and assess the safety due to these interaction forces on CWR. The interaction takes place due to expansion or contraction of deck and rails under change of temperature, longitudinal deformation of sub structure under braking, tractive forces from rolling stock and vertical bending/flexure of deck under live loads. SWR allows movements freely under thermal and live load effects whereas the rails as part of CWR doesn’t allow free moments and hence a separate analysis is required for study of interaction forces is required.