نوع مقاله : مقاله پژوهشی
نویسندگان
1 گروه زمین شناسی، دانشکده علوم پایه، دانشگاه بوعلی سینا، همدان
2 گروه مهندسی معدن، دانشگاه صنعتی همدان
3 گروه زمین شناسی، دانشکده علوم پایه، دانشگاه بوعلی سینا
چکیده
کلیدواژهها
موضوعات
عنوان مقاله [English]
نویسندگان [English]
The strength of a rock mass is directly affected by the presence of holes or flaws. This study investigates the effects of flaws and holes in granite rocks from the Alvand batholith in Hamadan. For this purpose, 19 rock cores were prepared with a length-to-diameter ratio (L/D) greater than 2. Holes and flaws with different arrangements and angles were created in these specimens. In some cases, a 10 mm diameter hole was added to the flawed specimens. The holes had a diameter of 10 mm, and artificial flaws with a 2 mm opening and a 20 mm length were created. The number of flaws varied from one to four, with angles of 0 or 45 degrees. It should be noted that one limitation during drilling was that holes drilled from the external surface sometimes caused the granite to fracture. After determining the physical and mineralogical properties of the specimens, uniaxial compressive strength (UCS) tests were performed. Strain was recorded using a strain gauge, and a camera was used to observe fracture propagation and crack formation. The specimens were then simulated using PFC3D software, and the laboratory results were evaluated. The results demonstrated a strong correlation between the laboratory findings and the numerical modeling. The presence of a hole alone caused a decrease in specimen strength; specifically, every 5 mm increase in hole diameter reduced the strength by approximately 15%. In specimens with 0-degree flaws, the strength was higher than in those with angled flaws due to the longer rock bridge. The lowest strength was observed in the specimen with four 0-degree flaws and a hole, which can be attributed to its short rock bridge compared to other specimens.
کلیدواژهها [English]
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