Experimental study on triaxial creep behavior of red sandstone under different pore pressures based on ultrasonic measurement

Zhou, Xiaoping; Shen, Fan; Berto, Filippo

doi:10.1111/ffe.13753

Cited by 5 publications

(5 citation statements)

References 49 publications

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“…In order to analyze the frequency characteristics of the waveform more intuitively, it can be converted into frequency-domain spectra according to the fast Fourier transform (FFT) to analyze the frequency components and distribution characteristics. The ultrasonic frequency response can reflect the damage state inside the rock . The ultrasonic frequency-domain spectra of D-type and S-type shale under the initial state and different impact velocities are shown in Figure .…”

Section: Resultsmentioning

confidence: 99%

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Damage Evolution and Splitting Failure Mechanism of Layered Rock under Dynamic Pulse Load

Wei,

Yang,

Zhai

et al. 2024

Energy Fuels

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In order to study the damage evolution and splitting failure characteristics of shale with different bedding orientations under dynamic pulse load, different impact velocities (40, 50, 60, 70 m/s) are selected to carry out dynamic pulse load on D-type and S-type shale samples. Ultrasonic testing, Brazilian splitting test [combined with digital image correlation technology and acoustic emission (AE) monitoring], and nuclear magnetic resonance are carried out on shale samples before and after impact. The results show that the P-wave velocity damage coefficient and splitting mechanic parameters of D-type shale show exponential attenuation, while those of S-type shale show linear attenuation. With the increase of impact velocity, the time-domain spectra of D-type and S-type shale show different degrees of waveform distortion. The frequency-domain spectra present a change characteristic of "high-frequency decrease, low-frequency increase", the total energy of energy spectra decreases, and the main frequency band shifts from medium frequency sub-band (fourth to sixth) to low frequency sub-band (especially first). The AE characteristics of D-type shale are peak distribution with obvious brittle fracture characteristics, while S-type shale is uniformly distributed with progressive failure characteristics. The horizontal strain cloud map shows a band-like stress concentration distribution. Before and after impact, the total porosity of D-type shale decreases, while that of S-type shale increases. The fractal dimension of mesopores generally increases, while the fractal dimension of macropores remained basically unchanged. The existence of the bedding surface is the main reason for the difference in fracture mechanism of different types of shale, and the weakening of the bedding surface caused by impact load is an important factor that complicates the complexity of this difference.

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Section: Resultsmentioning

confidence: 99%

“…The ultrasonic frequency response can reflect the damage state inside the rock. 45 The ultrasonic frequency-domain spectra of D-type and S-type shale under the initial state and different impact velocities are shown in Figure 5.…”

Section: Time-domain Spectramentioning

confidence: 99%

Damage Evolution and Splitting Failure Mechanism of Layered Rock under Dynamic Pulse Load

Wei,

Yang,

Zhai

et al. 2024

Energy Fuels

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“…Most of the rocks in engineering are under triaxial restricted status, especially in deeper rock masses. 48 The laboratory triaxial test plays a key role in inquiring into the failure behaviors and mechanisms for rocks, 49 and it is usually employed to determine the compression strength of rocks under different confining stresses. This study was conducted based on a triaxial compression test under isotropic confining stress conditions, which is applicable to the special case of a triaxial stress state, i.e., σ 2 = σ 3 .…”

Section: Triaxial Test and Regression Analysis 21 | Triaxial Mechanic...mentioning

confidence: 99%

“…Most of the rocks in engineering are under triaxial restricted status, especially in deeper rock masses 48 . The laboratory triaxial test plays a key role in inquiring into the failure behaviors and mechanisms for rocks, 49 and it is usually employed to determine the compression strength of rocks under different confining stresses.…”

Section: Triaxial Test and Regression Analysismentioning

confidence: 99%

Modified Mohr–Coulomb criterion for nonlinear strength characteristics of rocks

Xie,

Lin,

Chen

et al. 2024

Fatigue Fract Eng Mat Struct

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The classical Mohr–Coulomb criterion has an extremely wide range of applications in the field of engineering geology, while it cannot accurately characterize rock failure under high confining stresses. Therefore, a nonlinear modification is implemented based on the Mohr–Coulomb criterion for achieving wider usage in all stress environments. The cohesion and internal friction angle are firstly calculated by regression based on the triaxial experiments of diorite and other typical rocks in different confining stress ranges, and the variation modes of cohesion and internal friction angle are then formalized and integrated into the classical Mohr–Coulomb criterion. Using the experimental results of 435 triaxial compression tests in existing publications, the predictions of the modified criterion are compared with those of the previous nonlinear criteria, which show that the predicted values of the modified criterion are in good agreement with the measured strength. Compared with the previous nonlinear criteria, the modified criterion has a wider application range and always maintains a higher accuracy.

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“…However, when testing the initial ultrasonic velocity of the specimens, it was found that there were differences in the ultrasonic data obtained, even for the same type of specimen. Therefore, to facilitate the analysis of ultrasonic variation, the ultrasonic velocity was normalized [34,35]. The normalized ultrasonic velocity is defined as V ijB , and the ultrasonic velocity obtained from the nth wet and dry cycle of specimen number j in group i during the wet and dry cycle test is Vij(n).…”

Section: Change Rule Of Ultrasonic Velocity In Red Sandstone Specimensmentioning

confidence: 99%

Experimental Study on Erosion Modeling of Architectural Red Sandstone under the Action of the Natural Environment

Zeng,

Zhang,

Zhang

et al. 2024

Buildings

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When buildings are exposed to erosion from the natural environment, erosion behaviors such as surface damage and structural instability occur, which greatly affect the aesthetic value and service life of the buildings. The study of erosion behaviors and the establishment of a suitable erosion model are constructive references for the protection and restoration of buildings. In order to establish a suitable erosion model for architectural red sandstone, two types of red sandstone specimens were selected in this paper to carry out dry and wet cycle tests. Combining the theoretical analysis and the actual erosion situation, a unidirectional corrosion model is proposed to describe the erosion of buildings by the natural environment. In this model, it is assumed that only the outer surface of the building is in contact with external erosion factors for a long period of time, so this situation can be considered a unidirectional erosion process. The paper uses XRD, SEM, and ultrasonic methods to record changes in the properties of the red sandstone samples. Finally, the rationality of the unidirectional erosion model was verified numerically. The test results show that the red sandstone specimens subjected to erosion by the natural environment will be accompanied by the development of defects, such as cracks, fissures, and holes, as well as the generation of fresh material. The demarcation point of different erosion stages exists in both the in-service red sandstone specimens and the fresh red sandstone specimens, which is consistent with the results of the unidirectional erosion model. In this paper, a calculation model for the demarcation point of different erosion stages is established, and the model estimation shows that the demarcation point of different erosion stages of the in-service red sandstone sample is 1.1528 cm from the erosion surface, and the demarcation point of different erosion stages of the fresh red sandstone sample is 1.67 cm.

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Experimental study on triaxial creep behavior of red sandstone under different pore pressures based on ultrasonic measurement

Cited by 5 publications

References 49 publications

Damage Evolution and Splitting Failure Mechanism of Layered Rock under Dynamic Pulse Load

Damage Evolution and Splitting Failure Mechanism of Layered Rock under Dynamic Pulse Load

Modified Mohr–Coulomb criterion for nonlinear strength characteristics of rocks

Experimental Study on Erosion Modeling of Architectural Red Sandstone under the Action of the Natural Environment

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