https://nova.newcastle.edu.au/vital/access/ /manager/Index ${session.getAttribute("locale")} 5 https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:49916 Wed 14 Jun 2023 19:00:38 AEST ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:26734 Wed 11 Apr 2018 15:25:10 AEST ]]> 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:8025 Sat 24 Mar 2018 08:36:49 AEDT ]]> 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:12506 max) plays an important role in the failure process of specimens with two indenters. Furthermore, the heterogeneity of the rock can also affect the failure modes of the rock when two indenters are used. Finally, the numerical results demonstrate the effect of the spacing between the indenters on the rock.]]> Sat 24 Mar 2018 08:15:54 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:10885 Sat 24 Mar 2018 08:11:33 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:12148 Sat 24 Mar 2018 08:09:23 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:10492 Sat 24 Mar 2018 08:08:58 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:20450 2 on the peak strength, peak strain and crack initiation stress of the specimens. To confirm the sequence of crack coalescence, a photographic monitoring technique is used throughout the entire period of deformation. Based on the results, the relationship between the real-time crack coalescence process and the axial stress–strain curve of brittle sandstone specimens is also developed, and this relationship can be used to evaluate the macroscopic deformation characteristics of pre-cracked rock. The equivalent strain evolution fields of the specimen, with α = β₁ = 45° and β₂ = 90°, are obtained using the digital image correlation technique and show good agreement with the experimental results of pre-cracked brittle sandstone. These experimental results are expected to improve the understanding of fracture mechanisms and be used in rock engineering with intermittent structures, such as deep underground excavated tunnels.]]> Sat 24 Mar 2018 08:06:58 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:19256 Sat 24 Mar 2018 08:06:38 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:16726 Sat 24 Mar 2018 08:05:32 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:18146 Sat 24 Mar 2018 08:04:45 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:18130 Sat 24 Mar 2018 08:04:28 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:17761 Sat 24 Mar 2018 07:57:23 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:19206 Sat 24 Mar 2018 07:55:01 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:19205 Sat 24 Mar 2018 07:55:01 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:16866 Sat 24 Mar 2018 07:54:48 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:16849 Sat 24 Mar 2018 07:53:31 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:25475 Sat 24 Mar 2018 07:31:57 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:25690 D), based on the finite element method was used in this study to clarify this misperception. The RFPA²^D approach can account for rock heterogeneity and capture the entire rock failure process without prior assumptions regarding where and how microcracks and fracturing develop. Numerical models of rock were copied and reused in uniaxial and biaxial tests to create identical heterogeneous models for use under different confining stress conditions. Forty-five numerical tests (5 homogeneity indexes × 9 confining pressures) were used to calculate the results of the principal stresses (σ₁ and σ₃) at specified increments of axial strain. The intercept and the slope of a linear line fitting to the principal stresses at the same strain before peak strength were obtained in the principal stress space. The intercept is related to the cohesive strength component of the shear resistance, and the slope of the linear line is a pseudo-internal friction coefficient. Through the analysis of the linear fitting results, it has been found that the cohesive strength component increases while the pseudo-internal friction coefficient decreases with increasing homogeneity index of the numerical rock models. The values of cohesion and internal friction vary as a function of the strain state, and they are immediately activated with a strain increment before peak strength. The research results strengthen the understanding of the mobilization of the load-bearing capacity of rock mass surrounding an opening and can improve the design of practical support systems.]]> Sat 24 Mar 2018 07:28:20 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:22179 Sat 24 Mar 2018 07:16:24 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:22182 Sat 24 Mar 2018 07:16:23 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:22093 Sat 24 Mar 2018 07:15:15 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:23983 Sat 24 Mar 2018 07:11:07 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:24733 Sat 24 Mar 2018 07:10:58 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:40762 Mon 18 Jul 2022 14:01:32 AEST ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:40670 Mon 18 Jul 2022 08:32:25 AEST ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:34650 Mon 08 Apr 2019 13:03:16 AEST ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:32756 Fri 20 Jul 2018 16:27:15 AEST ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:43381 Fri 16 Sep 2022 09:16:25 AEST ]]>