Dynamic Fracture Test of Laurentian Granite Subjected to Hydrostatic Pressure
- 139 Downloads
Dynamic fracture failure of rocks subjected to static hydrostatic pressure is commonly encountered in deep underground rock engineering. The static fracture behavior of rocks under hydrostatic stress has been well studied in the literature. However, it is desirable to investigate the dynamic fracture failure of rocks under various hydrostatic pressures. In this study, a triaxial split Hopkinson pressure bar (SHPB) system is used to measure the dynamic fracture toughness of rocks under five hydrostatic pressures. The results show that dynamic fracture toughness under a certain hydrostatic pressure enhances with the increase of the loading rate, and the dynamic fracture toughness at the similar loading rate increases with the hydrostatic pressure due to the closure of microcracks in rocks. An empirical formula is proposed to describe the influences of the loading rate and the hydrostatic pressure on the rock dynamic fracture toughness.
KeywordsTriaxial SHPB Dynamic fracture toughness Hydrostatic pressure NSCB Fracture failure
This research was supported by the Natural Sciences and Engineering Research Council of Canada (NSERC) through the Discovery Grant # 72031326. This work was supported by Mitacs through the Mitacs Accelerate program. Shengwei Li and Zhili Tang helped conduct the experiments. Qi Zhao at University of Toronto helped conduct the CT scanning.
- 2.Thiercelin M (1987) Fracture toughness under confining pressure using the modified ting test. Paper presented at the 28th U.S. Symposium on rock mechanics (USRMS), Tucson, Arizona, 29 June - 1 July 1987Google Scholar
- 6.Ko TY, Kemeny J (2007) Effect of confining stress and loading rate on fracture toughness of rocks. Paper presented at the 1st Canada - U.S. rock mechanics symposium, Vancouver, Canada, 27-31 May 2007Google Scholar
- 7.Kataoka M, Mahdavi E, Funatsu T, Takehara T, Obara Y, Fukui K, Hashiba K (2017) Estimation of mode I fracture toughness of rock by semi-circular bend test under confining pressure condition. Paper presented at the ISRM European Rock Mechanics Symposium - EUROCK 2017, Ostrava, Czech Republic, 20-22 June 2017Google Scholar