Physical simulation of integrated protective structures

Nehrii, Serhii; Nehrii, Тetiana; Піскурська, Г. В.

doi:10.1051/e3sconf/20186000038

Cited by 8 publications

(7 citation statements)

References 10 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Instrumental observations in the ventilation raise have demonstrated that within mine workings, supported in front of the longwall, period of intensive shifts correlated with the period when the mine working gets to abutment pressure area. That coincides with common idea of deformation processes within mine workings being supported in a zone of longwall affect (Ma et al, 2018a;Ma et al, 2018b;Nehrii, Nehrii, & Piskurska, 2018). It is possible to determine general characteristic of the mine working deformation while analyzing its height variations depending upon distance to the longwall (Fig.…”

Section: Resultssupporting

confidence: 78%

Analyzing kinetics of deformation of boundary rocks of mine workings

Nehrii¹,

Sakhno²,

Sakhno³

et al. 2018

Min. miner. depos.

View full text Add to dashboard Cite

Purpose is to analyze nature of rock deformation and to estimate experimentally state of mine workings being supported under the conditions of areas disturbed by coal mining.Methods. The studies involved field instrumental observations within measuring points equipped with contour benchmarks. Express method was applied to determine height and width of the mine working; typical supported areas were designed; and photographs were taken. The research was conducted in a belt roadway and ventilation raise of western longwall 11 (c 18 seam of MM "Pivdennodonbaske No. 1"), and in their connections with the longwall.Findings. It has been determined that the longwall effect in the mine working, being supported repeatedly, is 80 -60 m in front of a stope; vertical convergence within the area is more than 1 m; floor rise share is almost 76%; and share rate is more than 3 mm/day. It has been specified that local destruction of anchor fitting as well as almost 70% of deformation of frame support is observed within the zone of the longwall affect. It has been identified that potential inrush area from the belt roadway is between supports 3 and 9 of a face zone support; i.e. distance from the seam edge is more than 2.4 m. It has been proved that the use of rigid protective structures is not efficient in the context of soft floor rocks since the protective structures function like dies. Condition of the belt roadway, being constructed and supported behind the longwall, is satisfactory; boundary deformations are within the range of the support flexibility.Originality. Regularities concerning deformation of boundaries of mine workings under the conditions of unstable wall rocks of c 18 seam (MM "Pivdennodonbaske No. 1"), when the mine workings are being constructed and supported behind a stope to be used repeatedly for following longwall, have been determined. Regularities of the process when rocks are forced out into a mine working cavity remained after protective structure, being constructed along a mine working at the boundary of the worked-out area, have been identified as well as regularities of vertical convergence rocks within terminal sites of the longwall.Practical implications. The findings can be used to develop measures and means for the stability of development mine workings under the conditions of unstable wall rocks and measures to prevent their fall within the tail longwall sites.

show abstract

Section: Resultssupporting

confidence: 78%

Analyzing kinetics of deformation of boundary rocks of mine workings

Nehrii¹,

Sakhno²,

Sakhno³

et al. 2018

Min. miner. depos.

View full text Add to dashboard Cite

show abstract

“…These allow solving geomechanical problems with a wide array of parameters very quickly. The following packages are the most popular: ANSYS [12 -14], Solid Works [14], PLAXIS [11, 15 -19], FLAC3D [20 -22] and PHASE-2 [23 -25]. These software systems give almost identical results [30] but differ in the degree of complexity in constructing the model's geometry and in using different models of material behaviour when setting tasks.…”

Section: Main Partmentioning

confidence: 99%

Problems of mining the prospective coal-bearing areas in Donbas

Nehrii

Bachurin

et al. 2019

E3S Web Conf.

Self Cite

View full text Add to dashboard Cite

The prospective coal-bearing areas of Donbas in Ukraine have been identified. Their development will increase the energy security of Ukraine. It has been suggested that the development of these areas will involve mining the coal seams in a weak roof and floor environment, which are characterized by low compressive strength, lower density and a tendency to plastic deformations. The stability has been assessed of the rocks outcrop on the contour of mine roadways for mines operating in these areas. It has been determined that roof rocks in most of these mines belong to a range of groups from very unstable to moderately stable, and the bottom rocks are, in most cases, prone to swelling. This complicates the intensive prospective areas mining with the use of advanced technologies, as well as secondary support for retained goaf-side gateroads with limited yielding property. The mines have been determined, for which this issue is relevant when mining the seams with further increase in the depth. The mechanism of displacement in the secondary supports and has been exemplified and studied using the numerical method. The obtained results allowed us to substantiate the necessity of developing new technical solutions for the protection of gateroads under conditions of prospective Donbas areas.

show abstract

“…Hence, potential energy of roof deformation for calculation alternatives, represented in Figure 1 and 2, is accumulated similarly in terms of the quantitative index. Through the changes in the value and geometry of vertical stress gradient, taking place in the process of complete backfilling, distance between the main cracks increases relative to packs resulting in the formation of larger rock blocks (Sotskov, Russkikh, & Astafiev, 2015;Nehrii, Nehrii, & Piskurska, 2018).…”

Section: Effect Of Technological Parameters Of Packs and Complete Backfillingmentioning

confidence: 99%

Analysis of operation parameters of partial backfilling in the context of selective coal mining

Sotskov¹,

Dereviahina²,

Маланчук³

2019

Min. miner. depos.

View full text Add to dashboard Cite

Purpose is to determine factors of effect of mechanical parameters and geometry of packs, constructed using the undercut rocks in the process of selective coal mining, on the state of geomechanical system within a mine workingstope junction during a computational experiment. Methods.The computational experiments involved finite-element method to simulate three-dimensional analytical area of the geomechanical system. Rock mass was represented by twelve rock layers and a coal seam. In the process of the computations, neighboring rock layers displace freely relative to each other. Stresses and deformations have been calculated within a full-size 300×160×50 m block involving undisturbed rock mass, a stope and two development workings. Mechanical characteristics of packs were simulated using additional analytical calculations.Findings. The calculations of a geomechanical system of a mine working-stope junction have helped determine typical areas of the disturbed rock mass identifying a propagation mechanism of the stope roof fall taking into consideration the effect of backfilling parameters. Analysis of stress-strain state (SSS) of the geomechanical system within the stope roof, using the selected cross-sections, made it possible to define conditions of interaction of the rock layers resulting in the roof lowering on the packs.Originality. The identified regularities of interaction between a stope roof and backfilling components determine optimum conditions to control a stope roof during selective coal mining. It has been substantiated scientifically that consideration of longitudinal horizontal stresses to identify optimum backfilling parameters makes it possible to define unambiguously both a type, and geometry of protection schemes for the mined-out area of a stope in terms of different strength parameters and geometrical parameters of the disturbed rock mass. Practical implications.The results have helped determine a mechanism of a stope advance velocity as well as a type and geometry of the packs being constructed. The abovementioned makes it possible to minimize expenditures for internal logistics; to cheapen prime cost of mining; and to improve safety of stope miners.

show abstract

Physical simulation of integrated protective structures

Cited by 8 publications

References 10 publications

Analyzing kinetics of deformation of boundary rocks of mine workings

Analyzing kinetics of deformation of boundary rocks of mine workings

Problems of mining the prospective coal-bearing areas in Donbas

Analysis of operation parameters of partial backfilling in the context of selective coal mining

Contact Info

Product

Resources

About