Effects of repeated blasting on a wood-frame house.
Stagg-MS; Siskind-DE; Stevens-MG; Dowding-CH
Minneapolis, MN: U.S. Department of the Interior, Bureau of Mines, RI 8896, 1984 Jan; :1-82
The Bureau of Mines arranged to have a wood-frame test house built in the path of an advancing surface coal mine so it could investigate the effects of repeated blasting on a residential house. Structural fatigue and damage were assessed over a 2-yr period. The house was subjected to vibrations from 587 production blasts with particle velocities that ranged from 0.10 to 6.94 in/s. Later, the entire house was shaken mechanically to produce fatigue cracking. Failure strain characteristics of construction materials were evaluated as a basis for comparing strains induced by blasting and shaker loading to those induced by weather and household activities. Cosmetic or hairline cracks 0.01 to 0.10 mm wide occurred during construction of the house and also during periods when no blasts were detonated. The formation of cosmetic cracks increased from 0.3 to 1.0 crack per week when ground motions exceeded 1.0 in/s. Human activity and changes in temperature and humidity caused strains in walls that were equivalent to those produced by ground motions up to 1.2 in/s. When the entire structure was mechanically shaken, the first crack appeared after 56,000 cycles, the equivalent of 28 yr of shaking by blast-generated ground motions of 0.5 in/s twice a day.
Mining-industry; Coal-mining; Surface-mining; Vibration-effects; Vibration; Explosion-damage; Explosions; Blast-effects; Wooden-structures; Structural-analysis; Fatigue-tests; Field-tests
IH; Report of Investigations
NTIS Accession No.
Minneapolis, MN: U.S. Department of the Interior, Bureau of Mines, RI 8896