Vibration Tests of Buildings for Evaluation and Identification

Dynamic tests of four buildings are described. Three of these were tested under controlled forced vibration. and one was shaken by a” actual earthquake. Threedimensional behavior of these vibrating buildings is investigated and shown to increase the strength of the structures. Three of the buildings exhibit very flexible foundations which substantially modify the vibration characteristics of the buildings. Post-earthquake testsand analyses revealed the nature and extent of the damage for two of the buildings.