where d is the particle size of the broken coal gangue mm; D is the largest particle size of the broken gangue mm; M d is the mass of broken gangue in the rock sample with a particle size smaller than or equal to d g; M t is the total mass of broken gangue in the sample g; and n is the Talbol power exponent Test procedure The above crushed rock mass compaction system
Darcy 4 、、、Darcy
The internal mesoscopic fabric evolution of crushed gangue during its bearing process particle breakage particle movement and force chain evolution are the root causes affecting the macro
In solid backfilling coal mining SBCM the deformation resistance of crushed gangue particle material CGPM is critical for controlling overburden strata movement and ground surface engineering practice CGPM is generally circularly compacted first by the compaction machine to reduce its a systematic approach to guide the
The stress strain relationship of crushed gangue in the compaction process increases exponentially and can be divided into void compaction stage structure adjustment stage and elastoplastic
The coal gangue was taken from Xin an Coal Mine in Luoyang Henan Province The lithology of the gangue was sandstone and the average density of the gangue was × 10 3 kg/m 3 with an average uniaxial compressive strength of reduce the impact of boundary effects on the results He et al 2022 the larger gangue particles were crushed
The crushed gangue materials which are filled into the goaf in solid backfilling coal mining become the main body of bearing the overburden after the tamping process Its resistance to deformation is
Deviatoric stress strain curves and overall deformation of crushed gangue under triaxial compression The deviatoric stress strain curve and overall deformation of crushed gangue under different confining pressures are shown in Figs 1 and and2 2 can be concluded from the Figs 1 and and2 2 that in the triaxial compression process of crushed
Crushed gangue models were made by gangue block containing single shape blocks or mixed shape blocks The influence of block shape on the macro deformation response and meso fabric evolution of crushed gangue under triaxial compression was studied Li
ABSTRACT To accurately estimate the separation effects and breakage characteristics of coal and gangue particles CGPs it is of great significance to understand the meso morphologies of CGPs and their correlations with different crushing conditions In the present work the impact crushing tests were conducted to obtain the effects of sizes gangue
The gangue block has an extremely irregular appearance and shape with sharp edges and convex undulations on the surface Consequently the obvious occlusive effect and stress concentration of gangue blocks are caused in crushed gangue materials during the load compression process [15] [16] [17]
Graded crushed gangue in the compaction process will be accompanied by the re crushing of the particles and the re crushing of the particles will in turn affect its grading state changing the compaction characteristics of the graded gangue and its bearing strength; that is the granular re crushing process will be presented to analyze the
Keywords Backll mining · Crushed gangue · Compaction process · Fractal dimension · Energy dissipation Introduction The high intensity development and utilization of coal resources have caused surface subsidence roof hazards and solid waste accumulation which has seriously inuenced the high quality coordinated development of the ecological
The gangue block has an extremely irregular appearance and shape with sharp edges and convex undulations on the surface Consequently the obvious occlusive effect and stress concentration of gangue blocks are caused in crushed gangue materials during the load compression process [15] [16] [17]
The irregular shape of gangue blocks will affect the coordination structure between blocks in the crushed gangue accumulation body and then affect the engineering mechanical Numerical Simulation of Coal s Mechanical Properties and Fracture Process Under Uniaxial Compression Dual Effects of Bedding Angle and Loading Rate Jianchun Ou
1 Introduction After coal mining many mined out spaces are formed underground which causes strata movement damage surface subsidence and collapse [1 5] Simultaneously a large quantity of solid wastes such as gangue is discharged in the coal mining process [6 10] Gangue discharge and surface subsidence control are common
Deformation of Crushed Gangue under Different Water Content Conditions Appl Sci 2023 13 The strain stress relationship in the compaction process of crushed gangue and the crushing law of
In solid backfilling coal mining SBCM the crushed gangue backfilling material CGBM is generally compacted circularly by a compaction machine in order to reduce its compressibility In this cyclic compaction process the particles are crushed which has a significant effect on the deformation resistance of CGBM However the deformation resistance
The crushed particle size came from the complete caved zone gangue in the longwall goaf of a mine The maximum thickness of the caved zone was about 20 m and the
Then X ray computed tomography XCT scanning with different resolutions was conducted on uncrushed and crushed CGPs followed by a series of image processing and analysis procedures Finally the effects of different impact velocities on the evolution of morphological parameters the fracture ratios and the fractal fragmentation characteristics
was monitored in the process of confined compression The test results showed that with the increase of loading rate the anti deformation ability of crushed gangue showed a dynamic change process of
