rock concasseur creep

Determination of the parameters of rock viscoelastic creep
2023.4.7 The creep parameters of rock under different stress levels and at different times are calculated by combining the results of triaxial indoor creep test and using the
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Review of the creep constitutive models for rocks and the
2024.5.28 The creep behavior of rocks has been broadly researched because of its extensive application in geomechanics. Since the time-dependent stability of
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New accelerated rock creep model considering
2024.3.1 Accelerated creep models are popular research topics in rock mechanics. By analyzing the variation in the viscosity coefficient in the accelerated creep stage and
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Creep damage constitutive model of rock based on the
The research investigated the creep characteristics, strain rate features, and damage properties of the sandstone. Based on the experimental results, the constitutive damage
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A true triaxial creep constitutive model of rock considering
2023.12.15 The proposed creep model successfully captures the creep curve characteristics of rock during the instantaneous elastic strain stage, steady-state creep
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Modeling of the creep and nonlinear damage effects of
2024.2.9 Many of these models require several curve-fitting parameters that lack physical significance. This paper aims to put forward a nonlinear damage creep model
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Experimental Study on the Accelerating Creep of Rock Under
2024.3.21 Creep tests under constant stress are among the most important tests for investigating the time-dependent behavior of rock. In previous studies, creep tests were
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Long-term creep and microscopic deformation ... - Oxford
2022.4.30 Time is the main governing factor in rock rheological creep study. The current study focuses on the microscopic deformation of selected rock using rheological
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A viscoelastic–plastic constitutive model incorporating creep ...
2024.1.22 To accurately characterize the deformation and failure behavior of the surrounding rock near the goaf in deep small coal pillars, we have developed a
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Slow-to-fast transition of giant creeping rockslides
2020.3.12 Giant creeping rockslides in crystalline rocks represent major threats to human life and infrastructures 1, 2 due to their volume (10 6 –10 8 m 3) and
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DEM simulation of rock creep in tunnels using Rate Process Theory
2022.2.1 To analyze the rock creep response in tunnels, the numerical model is needed first. A circular tunnel with a radius of 5 m is employed (see Fig. 4 a) and, to minimize the computational cost, (i) a quarter of the tunnel section (rather than the whole section) is modelled, and (ii) pressure loads are applied on the top and right walls to
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Influence of joints on creep processes involving rock masses:
2020.4.1 The damage at micro- and macro-scale affect the mechanical behavior of rock and its time-dependent deformations. 24 By adopting an equivalent continuum approach and a physical-analogue approach on a small scale, it was not possible to analyze directly the damage of rock as a collapse forerunner, even because the tertiary creep
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Rock Creep Deformation Triggered by Dynamic Disturbance:
2022.5.6 Numerical simulation indicated that the dynamic disturbance could accelerate the damage of rock under creep stress, which may be an important factor to trigger the accelerating creep of rock, even though the unstable failure of rock lagged behind the dynamic disturbance. The case study on the shaft stability analysis indicated that the
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Experimental Study on the Accelerating Creep of Rock Under
2024.3.21 Creep tests under constant stress are among the most important tests for investigating the time-dependent behavior of rock. In previous studies, creep tests were conducted under various loading and environmental conditions; however, it was very difficult to demonstrate accelerating creep at failure at stresses less than 50% of strength in
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Measurement and mathematical modelling of the creep
2014.2.1 Eq. (7) can be used to determine the creep behaviour for different σs / σc ratios for the samples of Tuzköy rock salt region. To use Eq. (7) the values of σs, σc, t, Q, R, T, tmax, A, B and C must be known. The variables of σs / σc, t, Q, R and T that are the input parameters used in Eq. (7) can be easily found.
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An intrinsic model of rock damage creep based on the
2023.11.15 Through the comparison and analysis with the classical component model, it is found that the fractal damage creep model has the advantages of few parameters, high accuracy, and high computational efficiency. The conclusions of the study can provide a reference for the prediction of surrounding rock deformation in practical
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Thermo-mechanical effect on the drained creep behavior of a clay rock ...
2023.12.20 Conclusion. Thermo-mechanical effect on the creep properties of a typical clay rock was investigated by performing creep experiments under different thermo-mechanical conditions, including different σ 3 ′, σ 1 ′ − σ 3 ′, and a heating-cooling stage of 40 → 60 → 80 → 60 → 40 °C, after up to one-month saturation stages.
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Viscoelasticity-induced fracture behavior of rock-concrete
2023.2.1 To investigate viscoelasticity-induced fracture behaviors of rock-concrete interface, creep tests were conducted on the composite rock-concrete specimens with two interface roughness degrees, i.e. 4 × 4 and 7 × 7 interfaces, under two sustained load levels of 50%P max and 75%P max. After the 90-day sustained loading, the creep specimens
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A novel time-dependent damage constitutive model for
2023.9.20 Time-dependent damage models use a progressive damage variable to efectively represent the gradual growth and propagation of microcracks in rocks. These models successfully reproduce the primary, second-ary, and tertiary creep deformation stages of hard rocks (Cheng 2022; Cheng et al. 2022; Zhao et al. 2016).
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Progressive failure process of secondary lining of a tunnel under creep ...
2019.8.1 The Dujia mountain tunnel (Fig. 2) is located near the Longmen mountain fault, which is the seismogenic fault causing the Wenchuan earthquake in 2008.The tunnel is a two-way, four-lane, separated tunnel (the way from Guanyuan to Yaodu is called T-1, and the reverse way is called T-2) with a length of 1846 m, a width of 13 m, a height of 10.5
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Creep properties and constitutive model of salt rocks under
2023.11.30 Many researchers have conducted salt rock creep tests under different strain rates, temperatures, and stress levels, analyzing the impact of these factors on salt rock creep [[46], [47], [48]].He et al. [49] conducted a uniaxial step-loading creep test on salt rock specimens, with a total creep time exceeding 100 days, to study the creep
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A New Approach to Investigate Rock Salt Creep Behavior
2024.5.7 Abstract. Generally speaking, the rock formation with creep capability, where rocks undergo continuous deformation under constant stress, are commonly encountered especially in geomechanics, petroleum engineering, and mining science. This phenomenon significantly impacts the stability of underground engineering structures,
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Predicting time‐to‐failure in rock extrapolated from secondary creep ...
2014.2.15 All rock specimens tested showed this characteristic response including a transient decrease of the stress relaxation rate and the deformation rates, similar to the so-called primary creep regime or Andrade creep regime [da Andrade, 1910]. This is followed by a steady state relaxation stage, in which the deformation-time and related stress-time ...
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Creep level qualitative evaluating of crushed rock based on
2024.6.22 It is concluded that the creep level qualitative evaluating of this crushed rock is rated as Class II, which is characterised by a low creep level and small creep deformations (0–10 mm).
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Time-dependent cracking and brittle creep in crustal rocks: A
2013.7.1 In Fig. 8 b, we observe some differences in the normalised stress required to achieve a given creep strain rate for different rock types. In particular, the rocks for which we see the greatest differences are Tavel limestone (a micritic limestone with a porosity of about 10%) and Crab Orchard sandstone (a quartz-rich, highly cemented, sandstone ...
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Accelerated creep model for rock based on statistical
LIU Wen-bo, ZHANG Shu-guang, CHEN Lei, SUN Bo-yi, LU Ping-ping. Accelerated creep model for rock based on statistical damage principle [J]. Chinese Journal of Geotechnical Engineering, 2020, 42 (9): 1696-1704. DOI: 10.11779/CJGE202009014.
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A true triaxial creep constitutive model of rock considering
2023.12.15 The theory of rock creep models has undergone significant development over several decades; however, it has yet to reach a state of full maturity. The majority of theoretical models effectively describe the two distinct creep processes, namely attenuation and steady-state. However, there is a scarcity of models that comprehensively capture
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Triaxial creep test and PFC numerical simulation of rock
2023.10.20 In order to study the triaxial compression creep characteristics of rock samples containing cracks, indoor triaxial compression creep tests of intact rock-like specimens and rock-like specimens with cracks were carried out. Accordingly, the effects of confining pressure, axial stress level, and the inclined angle of prefabricated cracks on
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Uncovering the creep deformation mechanism of rock-forming
2022.3.1 Creep is a process where deformation increases under constant stress and generally, the laboratory creep tests of rocks have three stages, namely, primary (transient) stage, secondary (steady-state) stage and tertiary (accelerated) stage [2].Nevertheless, the tertiary creep phase may not exist at low temperature, low stress and low pore-water
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Study on very long-term creep tests and nonlinear creep
2021.10.1 A reasonable explanation of the time-dependent deformation behavior of salt rock is essential for reliable model calculations and optimal design of salt caverns. 4 The uniaxial creep test results for 21000 h (875 days) under different axial stresses are shown in Fig. 3, including axial and lateral creep strain.Salt rock has obvious time-dependent
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Experimental investigations on the shear strength and creep
2024.1.1 The creep properties of soil-rock mixture (SRM) usually exhibit high variations after suffering harsh field conditions in cold regions such as freeze-thaw cycles, which can easily trigger landslides and threat the long-term stability of SRM slopes. However, the creep properties of SRM induced by freeze-thaw cycles have not been
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Rock shear creep modelling: DEM – Rate process theory
2023.1.1 Discrete element method (DEM) Rate process theory (RPT) Rock shear creep (RSC) Creep strain. 1. Introduction. Creep is the permanent deformation of a material under a persistent stress field (Kuhn and Mitchell, 1993). Creep can occur in individual materials like soils, rocks, or concrete, but also at interfaces between them (e.g., rock
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A creep model for ultra-deep salt rock considering thermal
2024.2.1 The creep behaviors of impurity rock salt at various temperature are revealed. • A thermal and mechanical damage coupled creep model of rock salt is established based on fractional derivative. • The model can well simulate the whole process of salt rock creep, and predict the borehole failure in deep-buried conditions.
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The Phenomenon and Examples of Rock Creep - ScienceDirect
1993.1.1 Rock creep tests, in a more usual time interval, have been described elsewhere and the whole phenomenon of creep has basically been covered in the formulae (e.g. Volume 3, Chapter 6). With in situ rock, however, long-term creep under small stress should be considered. In this chapter are described three long-term experiments,
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A novel nonlinear fractional viscoelastic–viscoplastic damage creep ...
2023.11.1 1. Introduction. The time-dependent behaviour of rock-like geomaterials is the focus of research in rock mechanics and rock engineering. The creep-induced irreversible deformation has a great impact on the stability of rock engineering, especially the tunnel engineering (Zhang et al., 2019).Meanwhile, delayed deformation caused by the
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Concasseur à mâchoires ROC - ROC IMPACT
Les concasseurs à mâchoires Roc Impact, utilisés à travers le monde dans de nombreuses mines et carrières, sont réputés pour être fiables et robustes. Le type ROC dispose de larges ouvertures d’alimentation et de longues mâchoires ainsi que d’une grande course de concassage. Il est principalement destiné au concassage primaire de ...
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Modeling of the creep and nonlinear damage effects of
2024.2.9 The creep and nonlinear damage behavior of rocks are two main factors that can cause large deformations and instability in tunnels. In this paper, uniaxial compression creep and triaxial compression tests were conducted to analyze the time-dependent and damage-induced strain-softening response of sandstone obtained from a
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Numerical Simulation of Rock Creep Behavior with a
2016.5.5 Time-dependent creep behavior of rocks is crucial not only for assessing geophysical hazards, such as earthquake rupture and volcanic eruption, but also for analyzing the long-term stability of rock engineering structures, such as underground mines and underground excavations.In the present paper, multiple stress-stepping creep tests
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Creep constitutive model considering nonlinear creep
2024.1.1 In this study, rock samples were obtained from Beishan, an area now recognized as a preferable place to dispose of high-level radioactive waste [22], [23].The experimental sample is medium-grained granodiorite, with a particle density of 2.64 g/cm 3, a velocity of 3300 m/s and an average compressive strength of 155.12 MPa.First,
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