Diagnosing and modifying off-site blast effects by seismic means -- A case study
A series of complaints were received from the owners of a 130 year-old farmhouse that had been converted into a bed and breakfast establishment. It was determined that blast effects were most noticeable on the third floor of the farmhouse. A vibration study was proposed aimed at isolating the actual cause of the perceived vibration. To aid in this determination, a customized, split-cable seismograph utilizing three single component transducers was deployed both in the interior and exterior of the farmhouse for two primary blasts. By utilizing a monitoring technique involving both interior and exterior sensors from a single seismograph, vibration time-histories from the three locations could be time-linked, providing an accurate assessment as to the actual mechanism responsible for the complaints. In this case, the split-cable array provided data indicating a low frequency ground vibration effect. Amplification of structure vibration due to the matching of the natural frequency of the farmhouse and the transmitted ground vibration was identified as the probable cause of the complaints. Given the potential impact of low frequency energy with surrounding properties, an analytical approach based on the concept of linear superpositioning was used to determine optimum delay intervals to reduce the off-site impact of future production blasts. Single-hole test blast data was recorded with traditional seismographs and analyzed using vibration control software. Utilization of recommended blasthole sequencing, combined with a change in blast orientation, resulted in the elimination of complaints at the farmhouse, in reduced vibration values at other neighboring properties and in a reduction in the overall liability exposure.
- OSTI ID:
- 398349
- Report Number(s):
- CONF-9502142-; TRN: IM9649%%557
- Resource Relation:
- Conference: 11. annual symposium on explosives and blasting research, Nashville, TN (United States), 5-9 Feb 1995; Other Information: PBD: 1995; Related Information: Is Part Of Proceedings of the eleventh annual symposium on explosives and blasting research; PB: 348 p.
- Country of Publication:
- United States
- Language:
- English
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