... along the same stress and stress path protocol. Effects of pre-existing microcracks in the sample are hypothesized via directional observations of velocity changes as a function of differential stress and mean stress. Dynamic Young's modulus is observed to increase primarily as a function of mean stress...

... influences such as stress, temperature, electrical currents, and chemical agents, is also important to better design geotechnical structures. Most researchers agree that the mechanical properties along the rift orientation depend on the orientation of microcracks and fluid intrusions – which in turn...

... it to derive all elastic parameters in the principal material directions. Additionally, the specific shape of the specimen facilitates easy measurement of porosity, strain, and bulk modulus of WG, allowing us to investigate the isotropic orientation and uniformity of microcracks throughout the specimen's...

... which then destroyed the beam. geologist reservoir characterization strength specimen magnitude geology geological subdiscipline microcrack granite equilibrium microstructure orientation geometry resource engineering loading reservoir geomechanics redistribution boundary...

.... By employing the Weibull distribution, the model captures the variability in rock internal strength due to microcracks, porosity, mineral composition, and other factors. Furthermore, it integrates the temperature dependency of rocks' physical and mechanical properties when subjected to elevated temperatures...

... increase in sample volume and number of microcracks within the temperature range of 400 °C to 500 °C leads to changes in rock mechanical properties. Yavuz et al. (Yavuz et al., 2010) analyzed the influence of thermal damage on the physical properties of five types of carbonate rocks. Microscopic...

... propagate. The study examined how brittleness influenced acoustic emission (AE) properties, including cumulative AE energy, average frequency (AF), and rise time to peak amplitude (RA). The results show the ratio of macrocracks to microcracks formed during rock failure. Rock brittleness impacts the AF value...

... are drilled at different positions on the wellbore wall to test and obtain the distribution pattern of microcracks in the surrounding rock and to characterize their microdamage attributes. Numerical simulations are then carried out to further analyze the damage patterns to rocks near the wellbore caused...

... ABSTRACT: The microcracking processes in front of the rock fracture tip could determine the macro-fracture propagation. Understanding the effect of crack-parallel stress on the microcracking processes could facilitate characterization of fracture propagation in shales and guide hydraulic...

... was then simulated using a Distinct Element Method (DEM) code through Trigon logic to further compare the brittle failure characteristics with the experimental results. The collective results revealed that the tensile microcracks are the first to initiate during the failure with higher intensity compared to shear...

... strengthening behavior. However, the value of ( a − b ) decreases and the fracture permeability increases with the increasing number of heating-cooling cycles. Microstructural characterization results show that the number, length and width of microcracks in the granite samples increase rapidly...

... ABSTRACT Experimental rock mechanics testing provides an effective method for measuring physical properties, their dependencies, and their evolution due to the addition of localized microcracks in a controlled laboratory environment. In order to understand the contributions of microcrack...

... to the volume increase during compression at constant net stress. To further explain these results, the model of Rozhko (2021) based on the hysteresis of liquid bridges inside microcracks was applied. The stiffness associated with capillary forces is negative, indicating that capillary force may dominate...

... fracturing strength rock-concrete interface upstream oil & gas reservoir characterization mortar specimen rock mechanic international journal mining science tensile loading investigation sensor microcrack engineering granite fracture characterization interface tensile strength...

... the anisotropy is low, the orientation of the minimum velocity corresponds to the highly preferred orientation of plagioclase (010) and biotite (001). Image analyses showed that there is also preferred orientation of microcracks regardless of their size and thermal treatment level. Neutron diffraction...

... ABSTRACT: The phase-field method in damage mechanics is attracting increasing popularity in rock engineering, which bridges the gap between microcracking fracture mechanics and quantified damage mechanics. The quasi-static microcrack propagation can be well captured in FEM via the phase-field...

... stress to cause a breakdown in rock strength and initiate chemical weathering (Fletcher et al., 2006; Buss et al., 2008; Goodfellow et al., 2016). Goodfellow et al. (2016) showed evidence for distributed microcracking of the rock matrix surrounding biotite minerals upon oxidation and a coincident...

... ABSTRACT: This work presents a thermodynamic-consistent directional damage theory that considers the kinetics of microcrack growth for brittle rocks. The novelty of the theory is that the distribution density of microcracks is directly incorporated at the continuum level through the notion...

... heterogeneity (Suàrez-Rivera et al., 2002), and strength parameters (Mitaim et al., 2004). reservoir geomechanics microcrack failure mode critical cutter depth reservoir characterization scratch test particle failure mechanism transition strength cutter depth upstream oil & gas coefficient...

... characterization upstream oil & gas reservoir geomechanics barre granite hydraulic fracturing strength shear strain experiment relaxation experiment rock mechanics relaxation evolution microcrack international journal threshold relaxation stage structural geology stress relaxation multistage...