Experimental evaluation on rock failure mechanism with combined flaws in a connected geometry under coupled static-dynamic loads

Li, Diyuan; Gao, Feihong; Han, Zhenyu; Zhu, Quanqi

doi:10.1016/j.soildyn.2020.106088

Cited by 73 publications

(13 citation statements)

References 40 publications

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“…This indicates that the surrounding rock was damaged owing to the excavation unloading effect. The current results exhibit discrepancies compared with those of a previous experimental study [25,37], because the hole or cavern was prefabricated manually prior to testing. In the previous study, unloading-induced cracks were not generated, because the rock was fractured by persistent loading, which was attributed to the limited experimental techniques used for reproducing the unloading process.…”

Section: Stress Pathcontrasting

confidence: 91%

“…To better understand and prevent the aforementioned dynamic disasters, it is necessary to consider the combined effects of the external dynamic disturbances and the geological structure on the failure properties of deep underground structures. For example, Li et al [25] studied the failure mechanism of rock with ssure-opening aws under coupled static-dynamic loads. The crack process of rock under coupled loads was observed in real time by DIC system, and crack initiation positions and failure modes of granite specimens were summarized.…”

Section: Introductionmentioning

confidence: 99%

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Effects of External Dynamic Disturbances And Structural Plane On Rock Fracturing Around Deep Underground Cavern

Fan

Chen

Zhao

et al. 2021

Preprint

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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 discontinuities. Thus, a combined finite-element approach 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 plane. The 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 structures. The simulation results indicated 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 load (stress-wave amplitudes). The crack distribution around the circular cavern exhibited an asymmetric pattern, possibly owing to the stress-wave reflection behavior and attenuation effect along the propagation route. Geological 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 plane. Additionally, the dynamic disturbance direction led to variations in the crack distribution for specific structural planes and stress states. These results indicate that the failure behavior should be the integrated response of the excavation unloading effect, geological conditions, and external dynamic disturbances.

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Section: Stress Pathcontrasting

confidence: 91%

Section: Introductionmentioning

confidence: 99%

Effects of External Dynamic Disturbances And Structural Plane On Rock Fracturing Around Deep Underground Cavern

Fan

Chen

Zhao

et al. 2021

Preprint

Self Cite

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“…The DIC technique has been widely used in laboratory tests because of its advantages of real time, covering full-field, online and flexibility. Li et al [45] investigated the failure mechanisms of rock specimens with flaws under superimposed static and dynamic loads by using a modified SHPB device, and the cracking process was record in real time by DIC technique. Similarly, Lin et al [46] used the DIC technique to investigate the fracture process of a sandstone under three-point bending with a variety of notch positions.…”

Section: Introductionmentioning

confidence: 99%

Mechanical Properties of Roof Rocks under Superimposed Static and Dynamic Loads with Medium Strain Rates in Coal Mines

et al. 2021

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Roof rocks in coal mines are subjected to the combination of in situ stresses and dynamic stresses induced by mining activities. Understanding the mechanical properties of roof rocks under static and dynamic loads at medium strain rates is of great significance to revealing the mechanism of rock bursts. In this study, we employ the digital image correlation (DIC) technique to investigate the energy concentration and dissipation behaviors, failure mode, and deformation characteristics of roof rocks under combined static and dynamic loads. Our results show that both the static pre-stress and dynamic loading rate have significant effects on the uniaxial compressive strength of rock specimens. From the energy principle, when the static pre-stress is the same, both elastic strain energy density and dissipated energy density increase with increasing dynamic loading rate. The hazard of rock bursts increases with decreasing static pre-stress and increasing dynamic loading rate. At higher dynamic loading rates, more cracks are generated, and the failure becomes more violent. The crack initiation, propagation and coalescence processes are identified, and the failure mode is closely related to the evolution of the global principal strain field of the rock specimens.

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“…Therefore, the high‐speed photographic technique and the DIC technique are utilized to capture the progressive failure of double‐flawed granite samples subjected to impact loads. Random speckles are coated on the sample surfaces to increase the calculation accuracy of DIC 34,35 . Firstly, the white paint is lightly sprayed and evenly covered on the surface of samples.…”

Section: Experimental Methodologymentioning

confidence: 99%

Experimental study on the progressive failure of double‐flawed granite samples subjected to impact loads

Zhou

et al. 2021

Fatigue Fract Eng Mat Struct

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In this paper, the split Hopkinson pressure bar device and high‐speed camera system are applied to carry out the impact tests of fine‐grained granite samples with two parallel preexisting flaws, whose angles are 0°, 15°, 30°, 45°, 60°, 75°, and 90°. The dynamic compressive strength of the double‐flawed granite samples is affected by the flaw angle. By analyzing the experimental results, the peak strengths of the double‐flawed granite samples are in low level when the flaw angles are varying from 45° to 75°, while the peak strengths of the double‐flawed granite samples are in high level when the flaw angles are in the ranges of 0°–30° and 75°–90°. The strain concentration factor is investigated based on the digital image correlation technology. Moreover, the mechanical properties, energy absorption, cracking behaviors, failure modes, and the progressive failure mechanism of the double‐flawed granite samples under impact loads are revealed.

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Experimental evaluation on rock failure mechanism with combined flaws in a connected geometry under coupled static-dynamic loads

Cited by 73 publications

References 40 publications

Effects of External Dynamic Disturbances And Structural Plane On Rock Fracturing Around Deep Underground Cavern

Effects of External Dynamic Disturbances And Structural Plane On Rock Fracturing Around Deep Underground Cavern

Mechanical Properties of Roof Rocks under Superimposed Static and Dynamic Loads with Medium Strain Rates in Coal Mines

Experimental study on the progressive failure of double‐flawed granite samples subjected to impact loads

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