COMPARISON OF MICRO-INCH IN-PLANE AND OUT-OF-PLANE RESPONSE OF CRACKS TO BLAST VIBRATION AND WEATHER

摘要

Most studies of crack response have focused on opening and closing of a crack in theplane of the wall in which the crack occurs. Crack movement also occurs perpendicular ornormal to the plane of the wall. This paper will examine and compare the in-plane andout-of-plane (normal) response of cracks in two different residences near limestonequarries. In two locations, sensors that measure in-plane and normal displacement wereinstalled side-by-side on the same crack, allowing direct comparison of the two modes ofresponse. In a third location, a perpendicular pair of displacement sensors was installed ina corner of a room to observe the bidirectional response of the structure at a corner.Both long-term and dynamic data were recorded with the same sensors; temperature,humidity, and air over pressures were also recorded to compare blast and weather effects.Measurements show that ratios of out of plane to in plane response to dynamic eventscan vary. However, the ratios of out of plane (normal) response to vibratory events tothat of climatological change is still as small as the ratio for in plane crack responses.