Civil Engineering Association

GARAGE STRUCTURE VIBRATION TRANSMISSION TO HUMAN OCCUPIED SPACES

Parking garages designed to be separate, stand-alone structures are often very limber, longerspan structures with low resonant frequencies. They exhibit vibration characteristics ill suited for office, residential, hospital or other human occupancies. Expansion or extension of the garage structure for a proposed human occupancy should recognize differences between occupancies or usages and incorporate acceptable floor vibration design parameters. Three case studies are presented about investigations garage vibration, one for an office expansion above the parking level and two for continuous slab extension from garage to horizontally adjacent residential spaces. . Measurements were conducted to determine
resonant frequencies of driveway and parking areas and to determine vibration amplitude spectra for ambient and vehicle pass disturbance conditions. Ambient and disturbed
conditions are compared with human perception criteria (re: ISO 2631). Differences between garage driveway “sources” and parking “receiver” locations indicate transmission losses.Apparent resonant frequency (narrow band) and 1/3 octave amplitude spectra for ambient and disturbed condition are shown. Garage plans and photos are incorporated. Design implications for structural continuity between garage driveway and parking slabs and adjacent floor slabs for human occupancy are discussed with conceptual methods of reducing vibration amplitudes on receiver slabs for continuous and discontinuous slabs.