Mechanical properties and meso-structure response of cemented gangue-fly ash backfill with cracks under seepage- stress coupling

Hou, Jifeng; Zhang, Guo; Liu, Weizhen; Zhang, Yanxu

doi:10.1016/j.conbuildmat.2020.118863

Cited by 25 publications

(13 citation statements)

References 21 publications

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“…Yin et al [11] proposed an electrochemical treatment to improve the early age strength and deformation characteristics of CGFB. Hou et al [12] studied the mechanical properties of CGFB with cracks under different seepage water pressures, introducing the damage variable which can evaluate the seepage effect and crack effect, and discussed the damage evolution law of CGFB with cracks under the seepage-stress coupling, which is based on the theory of damage mechanics. Li et al [13] studied the effect of material composition on the performance of superplasticizer when the target slump was 250 mm by response surface methodology.…”

Section: Introductionmentioning

confidence: 99%

“…Wang [14] studied the proportion of cemented coal gangue-fly ash backfill mixtures, considering that when the mass ratio of cement fly ash to coal gangue is 1 ‫׃‬ 4 ‫׃‬ 5 and the mass fraction of solid material reaches 72%～75%, the quality indexes of cement slurry such as strength, dehydration rate, and pipeline characteristics can meet the requirements of goaf backfilling. Wu et al [15] carried out an experimental study on the transportability and pressure drop of the CGFB slurry through the loop pipe with the help of a pipe loop system built in laboratory and revealed and discussed the effects of solids concentration as well as ratios of coal gangue to fly ash, fly ash to Portland cement, and coal gangue to Portland cement on the pressure drop of the loop pipe flow of the fresh CGFB slurry samples [11][12][13][14][16][17][18][19][20][21][22].…”

Section: Introductionmentioning

confidence: 99%

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Effect of Concentration and Suspension Agent (HPMC) on Properties of Coal Gangue and Fly Ash Cemented Filling Material

Yang

Jin

Yin³

et al. 2021

Shock and Vibration

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Cemented coal gangue-fly ash backfill (CGFB) mixtures are utilized as the filling materials for backfilling the underground openings in coal mines. The freshly prepared CGFB slurries are commonly transported into the gobs through a pipeline. The mixture ratio of slurry concentration and suspending agent (HPMC) plays an essential role in transporting the slurry to goaf smoothly and efficiently. In this paper, the influence of slurry concentration and HPMC on the performance of coal gangue-fly ash cemented filling material was studied based on the response surface method. The prediction model of CGFB slurry slump flow, segregation rate, and bleeding rate was constructed. It is concluded that the segregation rate and slump flow of slurry are more sensitive to the variation of concentration. On the other hand, the bleeding rate of slurry is more sensitive to the change of HPMC content. Based on the established model, the reasonable mix proportion range of slurry concentration and suspending agent (HPMC) was obtained. In addition, three new CGFB mixtures have been tested, and the experimental results are in good agreement with the predicted values.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Effect of Concentration and Suspension Agent (HPMC) on Properties of Coal Gangue and Fly Ash Cemented Filling Material

Yang

Jin

Yin³

et al. 2021

Shock and Vibration

View full text Add to dashboard Cite

show abstract

“…They concluded that the ground pressure on the retaining wall was caused by water seepage in part of the soil bodies. Hou et al [30] analyzed the seepage-stress coupling effect on the mechanical behavior, damage evolution law, and the microscopic structural response of cracked cemented gangue-fly ash backfill (CGFB). Barros and Santos [31] provided a numerical simulation of water permeation of soil bodies based on the boundary element method.…”

Section: Introductionmentioning

confidence: 99%

Permeability of Sand-Based Cemented Backfill under Different Stress Conditions: Effects of Confining and Axial Pressures

et al. 2021

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Sand-based cemented backfill (SBCB) mining technology is instrumental in utilizing coal resources buried under the water bodies. SBCB is exposed to the long-term action of mining-induced stresses in the goaf and groundwater permeating via microcracks along the rock strata. Studying the permeability evolution of SBCB under varying stress states is crucial for protecting coal and water resources below the aquifer. This study is focused on the influence law of different stress states on the SBCB permeability exposed to groundwater, which was tested under different axial and confining pressures using a laboratory seepage meter, particle size analyzer, scanning electron microscope (SEM), and X-ray diffractometer (XRD). Best-fitting quadratic polynomials linking the SBCB permeability with confining and axial pressures, respectively, were obtained via statistical processing of test results. The permeability gradually dropped within the elastic range as the confining and axial pressures increased. Moreover, an increase in the confining pressure caused a more dramatic reduction in the SBCB permeability than the axial pressure. Finally, the SBCB seepage mechanism under different stress states was revealed based on the particle size analysis, XRD patterns, and SEM microstructure. These findings are considered instrumental in substantiating safe mining of coal resources below the water bodies and above the confined groundwater.

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“…In terms of physical model experiment, scholars are not limited to the study of the development process of fracture, creep law, and change of permeability coefficient under groundwater seepage; the influencing factors and failure mechanism of tunnel failure are also considered [34][35][36]. Wang simulated the tunnel collapse process during the excavation and proposed the progressive failure mechanism of surrounding rock under the influence of groundwater seepage [37].…”

Section: Introductionmentioning

confidence: 99%

Experimental Study on the Failure Mechanism of Tunnel Surrounding Rock under Different Groundwater Seepage Paths

Wang

Yang

et al. 2021

Geofluids

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The influence of groundwater on tunnel engineering is very complicated. Due to the complexity of water flow water pressure transfer and uncertain defects in the stratum, all of which are key factors with regard to the design of tunnel engineering. Therefore, the variation of surrounding rock during excavation and the deformation and failure of soft surrounding rock under different seepage paths of underground water after excavation systematically. Experimental results showed that the stress change of surrounding rock caused by tunnel excavation can be divided into 3 stages: stress redistribution, stress adjustment, and stress rebalancing. In the process of water pressure loading, water flow rate is closely related to the experimental phenomenon. The between stable loading water pressure pore water pressure of the tunnel surrounding rock and the distance from the measuring point to the edge of the tunnel obey the exponential function of the decreasing growth gradient. With the increase of loading pressure, the pore water pressure and stress at the top of the tunnel increase, and the coupling of stress field and seepage field on both sides of surrounding rock more and more intense. The failure process of the tunnel can be divided into 6 stages according to the damage degree. The final failure pattern of the surrounding rock of the tunnel is mainly determined by the disturbed area of excavation. The arched failure area and the collapse-through failure area are composed of three regions. The surrounding rock is characterized by a dynamic pressure arch in the process of seepage failure, but it is more prone to collapse failure at low water pressure. The results of this study are the progressive failure mechanism of tunnel under different groundwater seepage paths and would be of great significance to the prevention of long-range disasters.

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Mechanical properties and meso-structure response of cemented gangue-fly ash backfill with cracks under seepage- stress coupling

Cited by 25 publications

References 21 publications

Effect of Concentration and Suspension Agent (HPMC) on Properties of Coal Gangue and Fly Ash Cemented Filling Material

Effect of Concentration and Suspension Agent (HPMC) on Properties of Coal Gangue and Fly Ash Cemented Filling Material

Permeability of Sand-Based Cemented Backfill under Different Stress Conditions: Effects of Confining and Axial Pressures

Experimental Study on the Failure Mechanism of Tunnel Surrounding Rock under Different Groundwater Seepage Paths

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