Unexplained blasting vulnerabilities in a historic town

Historic residential and commercial structures in an early twentieth century town in the southeastern United States that is adjacent to a quarry have regularly and repeatedly been damaged, despite the diligent keeping of blasting levels below peak particle acceleration levels previously thought to be safe. This paper explores the possibility of the damage mechanism being blasting-induced partial, repetitive liquefaction and the investigation methodology that led to this conclusion. The detonation of high explosives has been used in research to induce liquefaction at designated field sites and in laboratories, but the possibility of this occurring as an unintentional side-effect of commercial blasting has not been explored. This paper evaluates data from an actual community to assess the likelihood that the recorded damage is being caused by the quarrying in the southeastern United States. Although the results are not definitive they are strongly indicative that induced liquefaction is endangering this historic town.