Study on triaxial creep test and theoretical model of cemented gangue-fly ash backfill under seepage-stress coupling

Hou, Jifeng; Zhang, Guo; Li, Jinbo; Zhao, Lijuan

doi:10.1016/j.conbuildmat.2020.121722

Cited by 40 publications

(12 citation statements)

References 15 publications

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“…In order to study the problem conveniently, it is assumed that the creep properties of expansive soils conform to the Boltzmann linear superposition principle [24], that is, the creep deformation of expansive soils can be obtained by summation of the deformation caused by the increment of the loads at all levels. The test data was processed using the Boltzmann superposition principle to obtain separate loading curves of expansive soils under different consolidation pressures.…”

Section: Results and Discussion 31 The Relationship Between Axial Strain And Loading Timementioning

confidence: 99%

Creep Properties of Expansive Soils under Triaxial Drained Conditions and its Nonlinear Constitutive Model

Kong

2021

Period. Polytech. Civil Eng.

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The creep behaviors of expansive soils play an important role in landslide prediction and long-term stability analysis. In this paper, triaxial drained compression creep tests of expansive soils were conducted on the improved stress-controlled triaxial apparatus. The test results show that only transient deformation and attenuation creep occur with low deviator stress, and the increment of axial strain increases exponentially with deviator stress increasing; while deviator stress reaches a certain value, attenuation creep, steady creep and accelerated creep all occur in a creep curve. Meanwhile, the volumetric strain presents the shear shrinkage characteristic at the initial stage of loading, and the shear shrinkage is small. With the extension of loading time, the volumetric strain gradually varies from shear contraction to dilatancy. When entering the accelerated creep stage, the development rate of volumetric strain increases sharply. Besides, isochronous stress-strain curves of expansive soils indicate that their creep process possesses nonlinear characteristics, and the nonlinear degree is related to creep time and stress level. Imitating the empirical formula of cyclic cumulative deformation of clay, a new nonlinear creep model is presented, which may well describe the creep property of expansive soils. Furthermore, critical failure stress could be obtained based on the proposed creep model. The ratio of the critical failure stress to conventional shear failure stress ranges from 70% to 80%, with average of 75.56%, therefore, critical failure stress may be estimated by conventional triaxial tests with the margin of error 5.5% within.

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Section: Results and Discussion 31 The Relationship Between Axial Strain And Loading Timementioning

confidence: 99%

Creep Properties of Expansive Soils under Triaxial Drained Conditions and its Nonlinear Constitutive Model

Kong

2021

Period. Polytech. Civil Eng.

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“…Zhai et al [28] derived a modified Shields number considering the twodimensional seepage. Hou et al [29] studied the effects of seepage on the long-term stability of cemented gangue fly ash backfill.…”

Section: Fig 1 -Sketch Of Central Route Of the Snwtp [1]mentioning

confidence: 99%

Study on the Influence of Sudden Change of Water Level on High Fill Canal Segment

Yuan

Xu²,

Nie³

et al. 2021

CEJ

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Extreme conditions will cause the water level of high fill canal segment to change suddenly, which will affect the velocity and pore pressure of the slope. In this paper, numerical method is used to study the influence of water level sudden change on seepage characteristics of high fill canal segment. HyperMesh software is used to establish the finite element model of typical high fill canal segment under complex foundation conditions. Through the combination of secondary development program and fluid-structure coupling calculation method, the fluid structure cou-pling effect of canal under sudden change of water level is analyzed in ABAQUS. The results show that when the water level changes suddenly, the pore pressure below the free water surface and the velocity near the free surface will be greatly affected.

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“…Three-dimensional in situ stress is a common state of underground rock strata. Research on the evolution of the mechanical state [7][8][9] of surrounding rocks in the mining face and underground roadways has been widely performed. Xiao et al [10] conducted triaxial compression tests on red sandstone under different water pressures and established the permeability-stress coupling relationship for the control of rock stability.…”

Section: Introductionmentioning

confidence: 99%

“…The results of the numerical simulation showed that the volume strain is determined by the interaction between the stress field and the seepage field. Hou et al [8] established a creep damage constitutive model of cemented gangue-fly ash backfill (CGFB) considering the seepage-stress coupling effect and explained the relationship between creep rate and hydraulic properties. Liu et al [21] carried out triaxial seepage tests on fractured rock mass with the fillings.…”

Section: Introductionmentioning

confidence: 99%

Experimental Study on Seepage and Fracture Characteristics of Cemented Rock Samples under Triaxial Stress

2021

Lithosphere

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To study the seepage and fracture characteristics of cemented rock strata, a series of triaxial seepage tests on cemented rock samples under different confining pressures and water pressures were carried out in this study. The triaxial strength, elastic modulus, volume strain, and the permeability of the cemented rock samples were analyzed by the seepage unit connection probability model and Kozeny-Carman model. Based on test results, the stress state of cemented rock samples was divided into four stages: nonlinear compaction stage, linear elastic stage, stress yield stage, and failure and postfailure stage. The triaxial strength of the cemented rock samples gradually increased with the increase of confining pressure but decreased with the increase of water pressure. The elastic modulus of the cemented rock sample increased with the increase of confining pressure but decreased with the increase of water pressure. Besides, the volume strain of the cemented rock sample was analyzed, and the volume strain change of the cemented rock sample was also classified into three stages: the increasing stage of crack volume strain, the stable stage of crack volume strain, and the decreasing stage of crack volume strain. Based on the results of triaxial seepage tests, the evolution of permeability was divided into the declining stage, increasing stage, and redescend stage. Through the seepage unit connection probability model and Kozeny-Carman model, the evolution of crack volume was obtained, and the evolution of crack volume with axial strain was also classified into three stages: the original pore closure stage, crack network expansion stage, and crack network closure stage. The permeability evolution and the crack volume evolution were also compared. The comparison results suggest that three stages of crack volume evolution are all ahead of three stages of permeability evolution, verifying that the crack propagation induces the formation of seepage channels in cemented rock samples. This research will provide a valuable reference for the study of instability and water inrush mechanism in cemented rock strata.

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Study on triaxial creep test and theoretical model of cemented gangue-fly ash backfill under seepage-stress coupling

Cited by 40 publications

References 15 publications

Creep Properties of Expansive Soils under Triaxial Drained Conditions and its Nonlinear Constitutive Model

Creep Properties of Expansive Soils under Triaxial Drained Conditions and its Nonlinear Constitutive Model

Study on the Influence of Sudden Change of Water Level on High Fill Canal Segment

Experimental Study on Seepage and Fracture Characteristics of Cemented Rock Samples under Triaxial Stress

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