Creep properties and energy evolution characteristics of weakly cemented rock under step loading

Hu, Shengmin; Chenxi, Zhang; Ru, Wenkai; Han, Jinming; Guo, Shuqin; Zhou, Xuedong; Yang, Liu

doi:10.1016/j.ijrmms.2023.105428

Cited by 14 publications

(3 citation statements)

References 22 publications

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“…Tarasov et al [30] discussed the role of elastic energy in determining the dynamic energy balance and the fracture mechanism operating during spontaneous failure during loading of different brittle rocks, which provides a certain theoretical basis for understanding the dynamic process of rock bursts. Hu et al [31] revealed the energy evolution law of weakly cemented sandstone under the action of creep, which provided a certain theoretical basis for the long-term stability of weakly cemented surrounding rock mine tunnels.…”

Section: Introductionmentioning

confidence: 99%

Study on Characteristics of Failure and Energy Evolution of Different Moisture-Containing Soft Rocks under Cyclic Disturbance Loading

Cao,

Tang,

Chen

et al. 2024

Materials

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During the coal mining process in soft rock mines with abundant water, the rock mass undergoes cyclic loading and unloading at low frequencies due to factors such as excavation. To investigate the mechanical characteristics and energy evolution laws of different water-containing rock masses under cyclic disturbance loading, a creep dynamic disturbance impact loading system was employed to conduct cyclic disturbance experiments on various water-containing soft rocks (0.00%, 1.74%, 3.48%, 5.21%, 6.95%, and 8.69%). A comparative analysis was conducted on the patterns of input energy density, elastic energy density, dissipated energy density, and damage variables of different water-containing soft rocks during the disturbance process. The results indicate that under the influence of disturbance loading, the peak strength of specimens, except for fully saturated samples, is generally increased to varying degrees. Weakness effects on the elastic modulus were observed in samples with 6.95% water content and saturated samples, while strengthening effects were observed in others. The input energy density of samples is mostly stored in the form of elastic strain energy within the samples, and different water-containing samples adapt to external loads within the first 100 cycles, with almost identical trends in energy indicators. Damage variables during the disturbance process were calculated using the maximum strain method, revealing the evolution of damage in the samples. From an energy evolution perspective, these experimental results elucidate the fatigue damage characteristics of water-containing rock masses under the influence of disturbance loading.

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Section: Introductionmentioning

confidence: 99%

Study on Characteristics of Failure and Energy Evolution of Different Moisture-Containing Soft Rocks under Cyclic Disturbance Loading

Cao,

Tang,

Chen

et al. 2024

Materials

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“…However, weakly cemented granular materials behaved nonlinearly regarding their bulk properties, and most micromechanical models cannot describe these characteristics [9,10]. From an energy perspective, the creep characteristics and energy evolution of weakly cemented rock were investigated through a triaxial graded loading creep test, while also revealing the energy dissipation theory-based energy evolution characteristics at each stage of creep [11]. The creep model is predominantly employed to characterize the creep behavior of loosely consolidated soft rock, Clarifying the mechanical properties of weakly cemented rock masses serves as the foundation for the study of fracture expansion in such geological formations, and it holds significant importance in exploring the failure characteristics of fracture structures within weakly cemented rock strata and uncovering the developmental patterns of water-conducting fracture zones.…”

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Evolution of Water-Conducting Fracture in Weakly Cemented Strata in Response to Mining Activity: Insights from Experimental Investigation and Numerical Simulation

Liu,

Zhou,

et al. 2023

Water

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The accurate prediction of the vertical extent of water-conducting fracture (WCF) zones in weakly cemented strata is particularly significant in preventing and controlling water hazards in western coal mines. The evolution of fractures in weakly cemented strata affected by mining disturbances was comprehensively analyzed by physical similarity models, numerical simulations, and field investigations. Results indicated that the development progress of water-conducting fractures can be divided into three phases: initial slow generation, subsequent rapid development, and eventual stabilization. The numerical simulation results revealed that in the initial stage of working face mining, the development of the plastic zone is limited, and there is minimal failure in the overlying strata; therefore, fractures are slowly produced without penetrating through the strata. When the plastic zone fully encompasses the entire main roof, it triggers severe shear failure in the overlying strata, resulting in rapid fracture propagation and penetration. Once the fracture height reaches a stable state, there is no further increase in the maximum vertical displacement of key strata, indicating the extensive collapse and compaction of the overburden as well as the stabilization of the fracture heights. A modified prediction equation for WCF in weakly cemented strata was obtained by correcting the traditional empirical formula based on field investigations. This modified prediction equation enhances the accuracy in predicting fracture heights and provides a theoretical reference to address the issue of the inaccurate prediction of the water-conducting fracture height in western mine rock strata.

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Long‐Term Creep Prediction of NEPE Propellant Based on SSM Method

Zhang,

Deng,

Shen

2024

Propellants Explo Pyrotec

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Throughout the entire operational lifespan of a solid rocket motor, the propellant grain experiences creep due to gravitational forces, potentially influencing the motor′s reliability. To enhance the efficiency of creep tests for solid propellants, short‐term (3000 seconds) creep tests were conducted on nitrate ester plasticized polyether (NEPE) propellant at stress levels of 0.15 MPa, 0.20 MPa, 0.25 MPa, and 0.30 MPa using both the step stress method (SSM) and the conventional constant creep test (CCT). Furthermore, mid‐term (10000 seconds) and long‐term (7 days) creep tests were conducted. Based on the traditional generalized Kelvin model, the Saint‐Venant body was incorporated to derive a visco‐elastic‐plastic model with overstress considered, and constitutive model parameters were determined through data fitting. The findings demonstrate the efficacy of the constitutive model in well characterizing propellant creep behavior. According to the model, the yield stress of NEPE propellant was determined to be 0.2302 MPa, representing a significant 64.03% reduction compared to its design strength. This insight holds relevance for structural integrity analysis and the evaluation of solid motor storage life.

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Creep properties and energy evolution characteristics of weakly cemented rock under step loading

Cited by 14 publications

References 22 publications

Study on Characteristics of Failure and Energy Evolution of Different Moisture-Containing Soft Rocks under Cyclic Disturbance Loading

Study on Characteristics of Failure and Energy Evolution of Different Moisture-Containing Soft Rocks under Cyclic Disturbance Loading

Evolution of Water-Conducting Fracture in Weakly Cemented Strata in Response to Mining Activity: Insights from Experimental Investigation and Numerical Simulation

Long‐Term Creep Prediction of NEPE Propellant Based on SSM Method

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