Long term field measurement of micro meter crack response to climatological and blast vibration induced effects

This paper compares more than two years of micrometer crack displacement response and structural velocity response of a wood frame house adjacent to an operating aggregate quarry. The same transducers that monitor long term, climatologically induced micro-inch crack response also measure dynamic responses induced by blast-induced ground motions, occupant activities, and wind gusts. The two-story house has been expanded several times, is founded on an irregular basement, framed in wood and clad with wood siding and clapboard. This project is part of a larger research effort of structural health monitoring via autonomous crack monitoring [ACM]. The unusually long monitoring period allowed observation of two maximum, climatologically induced peak crack responses, and as such represents one of the longest periods of continuous observation in the literature. These once a year peak climatological responses are compared with unusually intensive ground motions in excess of that allowed by regulation. Intense ground motions were legally possible because the test house is owned by the quarry and located on the quarry property. These comparisons show that climatic and environmental variations cause greater crack response than ground motions that exceed regulatory limits.