AASHTO R 8:96(2019) Standard Practice for Evaluation of Transportation- Related Earthborne Vibrations.
2.5. Concerns of anticipated or perceived damage can be related to structures or their contents. Practically all buildings contain tine cracks or imperfections that are not noticed until concern is stimulated by perception of abnormal vibrations. Evaluation of the potential effects of transportation-related earthborne vibrations requires documentation of the background or pre-existing condition of the structure or component of concern. Such an evaluation should also include a determination of the intrusive vibration characteristics (amplitudes and frequencies) at the point of interest. Dowding (1992) reviews the various methods for determining ground vibration frequencies. Analysis of the results may necessitate modtication at the vibration source or mitigation of effects at the location of concern.
3.1. A survey of the site should be made by personnel capable of locating, evaluating, and documenting significant or apparent evidence of distress. Such surveys preferably should be made before the onset of any objectionable vibration-producing activity. The scope of the inspection should be appropriate for both the subject of concern and the intensity of the vibrations. Photographic or video documentation of the inspection is recommended. Any procedures requiring intrusion on property should be specifically permitted by the property owner, preferably in writing. Specialists in vibration monitoring are often contracted for survey services.
3.2. All vibrations arriving at the monitoring location within the selected sensitivity range of the seismograph are recorded. For comparison purposes, it is often useful to obtain recordings of the normal or background vibrations at the site when the specific objectionable source is not present.
The sensitivity range of the instrument should be selected so that recording is initiated below the intensity of the objectionable vibrations and extends above the highest expected intensity. It may be necessary to estimate or predetermine the expected intensity level to be sensed in order to select the appropriate instrument range setting to be used during monitoring. It is necessary to determine the time when the vibration source is active. Specific activities of the vibration source, such as driving of piles. as opposcd to extraction, vibratory compaction, or pavement-breaking activities, should be indexed in time for proper correlation with the arrivals on the vibration records. Because the determination of frequency is important, instruments that provide a time-history or waveform of each velocity component for a vibration event arc preferred.AASHTO R 8 pdf download.