Study of Integral Structure behaviour for Rail Structure Interaction in the Proposed Metro Viaduct

Abstract

Long welded rails (LWR) are preferred in metro rail systems because they provide a smooth ride. They are extremely sturdy, require less maintenance and safe to travel at higher speeds. Rail structure interaction (RSI), especially additional longitudinal stresses in rail, is the major concern in the LWR. UIC standards provide the limitations of additional rail in longitudinal stresses. This paper studies the characteristics of additional forces in long welded rail used in one of the Metro Railway systems in India. The LWR is placed on five spans with integral intermediate piers of balanced cantilever superstructure (BCM). A nonlinear finite element analysis is performed using the analytical tool MIDAS CIVIL 2021 to study the interaction mechanism. For this study, rail and deck (unballasted) are linked with a multilinear elastic spring, as recommended in UIC 774-3R. The study was conducted in accordance with the International Union of Railways and Indian standards. This paper shows a comparison of the rail stresses along the rail due to combined thermal and live loading for both balanced cantilever span and conventional simply supported spans. The results show that rail stresses have significant variation due to bearing articulation, adjacent spans and integral BCM system.