| Summary: | 碩士 === 國防大學理工學院 === 軍事工程碩士班 === 101 === A direct shear test is the most typical experimental method to investigate the shear behaviors of rock joint. However, the shear rate of direct shear test suggested by ISRM is relative slow compared with the shear rate induced by earthquake events. In this study, a schemed direct shear experimental investigation with planar and regular saw-tooth joints is conducted. In order to improve the limitation of static shearing rate of traditional direct shear test, a high rate testing machine, MTS 819 high rate test system, is used as the frame of direct shear test, and the actuator of this hydraulic system could provide maximum shear rate to 40 mm/sec. Additionally, a bi-lateral direct shear testing setup is developed by NDU. A series of double shear test are carried out by detail planning, and the adopted shear rate is 10-2, 10-1, 100 and 101 mm/sec based on the scale exchanging with respect to earthquake magnitude. According to the experimental results, the peak friction angles of planar and 30° regular rock joint are increased slightly with the increasing of the shear rate, but the peak friction angle of 15° regular rock joint keep no change compared with the traditional direct shear test.
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