Abstract. The propagation attenuation law of elastic waves generated by rock mass fractures in strata is of great significance in explaining engineering problems, such as rock bursts. In this study, a wave velocity mo...
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The accumulation and release of deformation energy within the rock mass of a roadway are primary contributors to the occurrence of rock bursts. This study introduces a calculation model for the kinetic energy generate...
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This research uses cement-based rock as the subject, preparing cement-based rock-like samples with arc-shaped cracks with a 45° dip angle and different scales (similar in morphology but different in size). Combin...
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This research uses cement-based rock as the subject, preparing cement-based rock-like samples with arc-shaped cracks with a 45° dip angle and different scales (similar in morphology but different in size). Combining uniaxial compression tests with FLAC3D numerical simulation, this study systematically investigates the effects of arc-shaped crack scale on the mechanical properties, energy evolution, and failure patterns of rock masses. The results show that: ① The bearing capacity of cement-based rock-like masses with arc-shaped cracks of different scales varies significantly. The peak strength is highest at λ-20 mm (crack chord length 28.28 mm, arch height 5.86 mm, corresponding to arc-shaped crack radius 20 mm) at 24.57 MPa, while λ-40 mm shows the minimum peak strength at 8.52 MPa. This indicates that larger arc-shaped crack scales result in lower overall bearing capacity of cement-based rock-like materials, making them more prone to instability failure. ② Energy evolution patterns differ across specimens with different crack scales, with larger λ values exhibiting more pronounced stress concentration and acoustic emission activity, as well as earlier yielding and instability. Among these, cement-based rock-like specimens with λ-50 mm have the shortest time to instability failure, while samples with λ-10 mm maintain stability for the longest duration. ③ Failure morphologies of cement-based rock-like materials with different scale arc-shaped cracks show considerable differences. Crack initiation occurs first at both tips of the arc-shaped crack, with secondary crack propagation and coalescence being the primary causes of instability. However, as λ increases, secondary cracks appear earlier, and the development, propagation, and coalescence speed of cracks progressively intensifies, resulting in increasingly severe damage. ④ Speckle characteristics during failure show significant similarities and differences across specimens with different crack scales. Strain conce
The occurrence of disasters in deep mining engineering has been confirmed to be closely related to the external dynamic disturbances and geological ***,a combined finite-element method was employed to simulate the fai...
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The occurrence of disasters in deep mining engineering has been confirmed to be closely related to the external dynamic disturbances and geological ***,a combined finite-element method was employed to simulate the failure process of an underground cavern,which provided insights into the failure mechanism of deep hard rock affected by factors such as the dynamic stress-wave amplitudes,disturbance direction,and dip angles of the structural *** crack-propagation process,stress-field distribution,displacement,velocity of failed rock,and failure zone around the circular cavern were analyzed to identify the dynamic response and failure properties of the underground *** simulation results indicate that the dynamic disturbance direction had less influence on the dynamic response for the constant in situ stress state,while the failure intensity and damage range around the cavern always exhibited a monotonically increasing trend with an increase in the dynamic *** crack distribution around the circular cavern exhibited an asymmetric pattern,possibly owing to the stress-wave reflection behavior and attenuation effect along the propagation *** discontinuities significantly affected the stability of nearby caverns subjected to dynamic disturbances,during which the failure intensity exhibited the pattern of an initial increase followed by a decrease with an increase in the dip angle of the structural ***,the dynamic disturbance direction led to variations in the crack distribution for specific structural planes and stress *** results indicate that the failure behavior should be the integrated response of the excavation unloading effect,geological conditions,and external dynamic disturbances.
Fluid invasion through fractures is frequently observed in subsurface engineering. To elucidate the microkinetic behavior of fracture fluids, the microfracture structure of coal from the Surat Basin was reconstructed ...
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Fluid invasion through fractures is frequently observed in subsurface engineering. To elucidate the microkinetic behavior of fracture fluids, the microfracture structure of coal from the Surat Basin was reconstructed using a 3D morphometric system and stitching algorithm, then the transparent models characterizing the fracture structure were produced using microfluidics, and water invasion in the microfracture model was measured via visualization experiments under various conditions. High flow rate facilitated the invasion of the water phase into the closed channel, improving the efficiency of water invasion in the neutral wetting system. Wettability reversal changed the dominant channel for water invasion in the hydrophobic system. The invasion efficiency in closed and small aperture bypass channels was *** reduction of effective seepage channels led to the fastest breakthrough time. Higher surface tension and interfacial curvature promoted the hysteresis effect. The reduction of effective seepage channels led to the fastest breakthrough time. The larger surface tension and interfacial curvature make the hysteresis effect more significant. These results will enable a better understanding of the rock-gas-liquid multiphase interaction mechanisms under unsaturated conditions of rocks.
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