Papers - Seismic Methods - Seismogrqph Prospecting for Oil - Measurement of Ordinary House Vibrations (Abstract of Contrib. 108)

The amplitudes and frequencies of vibratiolls of a four-story stucco building were measured by specially developed electrocapacitive seismometers. Records were made on three floor levels with as many as 10 seismometers recording simultancously. Sources of vibration were: (1) an electric motor with unbalanced pulley, maximum speed 1800 r.p.m., maximum centrifugal force 90 lb., (2) truck traffic (both solid and pneumatic tires) moving over inequalities in the street in front of the house, (3) falling weights dropped on the street pavement from different heights, (4) miscellaneous sources, including a man jumping on the floor of the house and slamming doors. Tests were made to determine the natural frequencies of floor and wall panels by varying the speed of the unbalanced motor and by exciting the panels with a single impulse. The vibrations recorded were compared to records of vibrations from quarry blasts and it was observed that the vibrations from truck traffic were comparable to those recorded from quarry blasts and in no instance was there any damage to the building. As the tests were all of a negative character as far as damage was concerned, no index of destruction is formulated. Instead, the records are presented simply as vibration measurements obtained in an ordinary house under typical conditions.