https://nova.newcastle.edu.au/vital/access/ /manager/Index en-au 5 https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:17368 2D (rock failure process analysis), was used to simulate the initiation and propagation of fractures around a pre-existing single cavity and multiple cavities in brittle rocks. Both static and dynamic loads were applied to the rock specimens to investigate the mechanism of fracture evolution around the cavities for different lateral pressure coefficients. In addition, characteristics of acoustic emission (AE) associated with fracture evolution were simulated. Finally, the evolution and interaction of fractures between multiple cavities were investigated with consideration of stress redistribution and transference in compressive and tensile stress fields. The numerically simulated results reproduced primary tensile, remote, and shear crack fractures, which are in agreement with the experimental results. Moreover, numerical results suggested that both compressive and tensile waves could influence the propagation of tensile cracks; in particular, the reflected tensile wave accelerated the propagation of tensile cracks.]]> Wed 11 Apr 2018 13:17:24 AEST ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:12508 Sat 24 Mar 2018 08:18:42 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:16871 Sat 24 Mar 2018 07:54:48 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:53938  the intermediate principal stress σ2 > the minimum principal stress σ3 = 0), the biaxial compressive strength of granite presents a monotonous increasing trend with the σ2 increasing from 0 to 40 MPa, while the increasing rate of biaxial compressive strength increases firstly and then decreases with the increase in σ2. The rock failure induced by point/local fatigue loads with 5 kHz frequency was analyzed in this study. It shows that the fatigue life of granite is much shorter than that in the traditional full-section fatigue tests, which increases with the increase in σ2 and decreases as the upper level of the fatigue stress or predefined stress of σ1 increase. From the acoustic emission properties, the failure of rocks under biaxial confinements induced by point/local static or fatigue loads are mainly because of tensile cracks. Meanwhile, the application of a disturbance bar with a smaller cross-sectional area induces rock broken more quickly. It seems that the following measures can be used to improve rock breakage efficiency: increasing the predefined stress in the breaking direction, reducing the lateral confinement, using the breaking bar with a small cross-sectional area, and changing the static loading into the dynamic loading of the breaking force.]]> Mon 22 Jan 2024 16:48:53 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:47258 Fri 16 Dec 2022 14:56:22 AEDT ]]>