Numerical study of isolation in the backfill zone of foundation pit method to reduce railway generated vibration in high‐rise buildings

Abstract

The conventional methods to reduce building vibration include isolation of vibration sources, isolation of buildings, and setting trenches in the propagation path. However, it is evidenced that these methods are not feasible for high-rise buildings in crowded urban areas. This paper proposes a new method to reduce vibration for high-rise buildings by using the existing construction backfill zone, the isolation in the backfill zone of foundation pit (IBF). Numerical analyses were first carried out to obtain a realistic excitation time history, and a finite element-infinite element model was developed and calibrated using test data from an actual building site. The contributions of the basement sidewalls and foundation slabs to floor vibration and the influence of infill material properties are investigated. Lastly, a composite isolation layer was suggested to provide both sufficient restraining effects to the building foundation and satisfactory vibration isolation. The analyses confirmed that the proposed IBF method reduces ground-borne vibration in high-rise buildings by up to 66% when railway is on the ground. KEYWORDSbackfill zone of foundation pit, composite isolation layer, finite element-infinite element, high-rise building, inverse procedure, railway generated vibration reduction