UNDERGROUND RAILWAY VIBRATION MEASUREMENT, ANALYSIS AND REDUCTION IN ADJACENT RESIDENTIAL BUILDINGS

摘要

This work presents results of thorough investigations of vibration propagation from underground trains on Kalugsko-Rigskaja line of Moscow Underground. The main aim of the work was to develop effective countermeasures that reduce both the floor vibration and structure-induced noise inside scheduled closely adjacent residential compound. The distance between the residential compound and the tunnel casing varies from 15 to 52 m. Field investigations were performed to measure the ground velocity during underground train passes both on the ground surface and on the foundations of existing buildings. Transfer functions from ground to building foundation were calculated based on those measurements and the prediction of vibration inside the building was performed. Prediction analysis is conversion from the measured vibration levels on the ground surface to the vibration levels of the floors that consists of the following steps: 1) determination of the transfer function between the ground surface and the foundation of the residential buildings; 2) determination of the vibration transmission losses through the building structure; 3) calculation of the resonant increase of oscillations in the center of the floor compared to its contour. The paper presents calculated and averaged over the time of measurements transmission coefficients of vertical vibrations between the said groups of structural elements. The calculated transfer coefficients can be used to predict vibration levels in similar buildings subjected to underground traffic impact. Further analysis allowed for calculation of structural members' vibration velocity that were compared to valid sanitary standards. Vibration reduction measurements were proposed and their efficiency calculated.