EFFECTIVENESS OF TRACK STIFFNESS REDUCTION IN ATTENUATION OF METRO INDUCED VIBRATIONS RECEIVED BY HISTORICAL BUILDINGS

Abstract

PRESERVATION OF HISTORICAL BUILDINGS IS A MAIN CHALLENGE IN CIVIL ENGINEERING FIELD. ONE OF THE MAIN CONCERNS IN THIS REGARD IS METRO INDUCED VIBRATION RECEIVED BY THE HISTORICAL STRUCTURES. THERE IS A NEED TO EVALUATE EFFECTIVENESS OF VIBRATION MITIGATION MEASURES IN PRESERVATION OF MONUMENTAL BUILDINGS. THE MOST WIDELY USED METHOD OF REDUCING METRO VIBRATIONS IS CHANGES IN THE STRUCTURE OF THE VIBRATION SOURCE (NOT SUFFICIENTLY INVESTIGATED IN THE LITERATURE). IN RESPONSE TO THIS NEED, EFFECTIVENESS OF TRACK STIFFNESS REDUCTION IN MITIGATION OF VIBRATION WAS INVESTIGATED IN THIS RESEARCH.  COMPREHENSIVE FIELD TESTS WAS CONDUCTED IN THE IRANIAN METRO LINES. THE TRACK STIFFNESS AS WELL AS THE INDUCED VIBRATIONS WERE MEASURED.  THROUGH ANALYSES OF THE DATA OBTAINED, THE VIBRATION REDUCTION AS A FUNCTION OF TRACK STIFFNESS WAS DERIVED. IT WAS SHOWN THAT TRACK STIFFNESS HAS NOTICEABLE IMPACT ON THE TRACK LEVELS OF VIBRATION, AND IN TURN ON METRO VIBRATION REDUCTION. THE RESULTS WERE ALSO USED TO MAKE IMPROVEMENTS IN THE ACCURACY OF THE FTA VIBRATION PREDICTION