Tom 24 2008 Zeszyt 4/3
VICTOR G. CHERVATYUK*, VITALIJ V. VASILYEV*, VOLODYMYR V. BUZYLO**, IRYNA A. KOVALEVSKA**
The modern aspects of the anchor fastening use in the environment of SC “Pavlogradvugilla”
The world experience of anchors use for the security of underground mine workings stability indicates that this kind of support has considerable economical advantages that allow to make sharp reduction of material and work costs and to increase production productivity and work safety. It can be achieved by the involvement of edge rockmass with the help of anchor support into the gravitation force resistance activity; it means that strength properties of the mass itself are being used in some extent and there is no necessity to mount resource-demanding supports constructions for mine workings maintenance.
The advantages of anchor support stated above stimulated its wide application in mineral resource branches of industry.
At present in domestic and foreign practice more than 600 anchors constructions are known [1]. As a rule, existing variety of anchor supports is divided into two big classes – locking (those which engage with the pack walls of a borehole on the relatively small area of its surface) and non-locking (those which are fastened during the whole or the most part of a borehole) [2, 3]. Both these classes of anchors constructions have their advantages and disadvantages which are necessary to analyze thoroughly both from the viewpoint of geomechanics and engineering-and-economical performance of enter- prise work; the ultimate goal is to create the anchor construction with the most efficient rate of the interaction with borehole pack walls and rockmass in whole with its relatively moderate cost.
** SC “Pavlogradvugilla”, Pavlograd, Ukraine.
** National Mining University, Dnipropetrovsk, Ukraine.
During the research and critical analysis of the modern anchors constructions three main criteria which are called to characterize the efficiency of either anchor support construction for mine workings maintenance were formulated.
From the viewpoint of edge rockmass hardening process geomechanics the first criterion make demands on attainment of anchor efficient deformative-and-force characteristics. In modern theories edge rockmass fastened with anchors is being considered as the carrying construction which takes the load from softening deforming rockmass side and operates as the support of working. Firstly, to secure effective mine workings maintenance the deformative-and-force characteristic of this support must correspond to the magnitude and nature of mine pressure manifestations; it means that the carrying capacity of rock cover hardened with anchors must not be less than load magnitude from the rockmass side and its flexibility must not be less than forecasting rock edge trace magnitude by given support repulse response magnitude.
Secondly, deformative-and-force characteristic of hardened rock cover must secure maximal degree of deforming compatibility of separate layers and blocks which lay down incompetent rocks to reduce support load. In connection with this several researches [4, 5–9]
have established that the deformative-and-force characteristic of support which reproduce its activity in the mode of constant resistance with response magnitude is the most efficient and is close to forecasting load on support from the weight of breakdown area rocks.
Thus, to maintain mine working efficiently anchor support has to form carrying con- struction which would work in constant resistance mode (or close to it) with the repulse reaction and flexibility magnitude exceeding or equal to forecasting load on support and rock edge displacement.
The third criterion characterizes the economical efficiency of different anchors con- structions application and formulates next requirements:
— relatively not high cost of anchor making,
— high production productivity during the mounting of anchors,
— the possibility of repetitive (multiple) use of anchors.
The analysis of deflected mode of supports and anchors has allowed to reveal pe- culiarities of anchors influence upon support stress field change. By this, stress field change has to perform towards stress concentration decrease and towards achievement of maximum on the conditions of support carrying capacity. The implementation of stated main requirement is based on following condition. In the hardened edge rockmass it is necessary to transform stress field with the help of anchors in such way that rock capacity stability in most dangerous areas (with the most stress concentration) could be increased.
Thereby, the analysis of anchor supports modern constructions with the stated geome- chanical, constructively-technological and economical requirements has shown that for the creation of favourable coal industry conditions the application of this hardening kind is perspective.
Currently, there is active implementation of anchor and frame-anchor fastening technology at the SC “Pavlogradvugilla”, which is the one of Ukrainian advanced associations.
Anchor fastening centre has carried out the inspection of workings which were planned for conducting with anchor and frame-anchor fastening. The documentation in the form of recommendations with the anchor fastening construction type, conclusions, the acts of compliance or discrepancy to the requirements of regulations, implementation conditions concerning workings state, edge rockmass state, fastening construction technology, the possibility of the workings implementation with purely anchor fastening, monitoring quality and completeness, workings reliability and safety.
In concordance with “The program of equipment acquisition and the application of anchor fastening during the carrying out of mine workings in 2006” it was stipulated that anchor technologies for fastening must be used during the work conducting.
In 2006 factual carrying out of workings with the use of anchor technologies was 2288 m.
Including:
— preliminary workings with anchor fastening – 418 m,
— preliminary workings with frame-anchor fastening – 668 m,
— overhaul workings with frame-anchor fastening – 243 m.
But appropriate conclusions were drawn as the results of anchor fastening program implication of 2006; and in 2007 there was anchor fastening program that included the carrying out of mine workings with the use of anchor technologies that were of 33086 m volume. The results of 2007 have shown that 5807 mof mine workings had been carried out with the use of purely anchor technology. 21184 m had been conducted with the use of frame-anchor technologies (this includes 6755 m of overhaul mine workings).
Fig. 1. The common view of the model that is used in the computing experiment Rys. 1. Ogólny widok modelu stosowanego w eksperymencie obliczeniowym
The plan of anchor fastening program for 2008 is to carry out 62583 m of mine workings.
This figure includes 55287 m of frame-anchor fastening use and 9296 m of pure anchor use.
For the first time for this year the anchor fastening program has planned the carrying out of overhaul mine workings with the use of pure anchor fastening of the volume of 1485 m.
In consideration with FEM peculiarities and the structural complexity of assigned task the block scheme of computing experiment was designed; its computing scheme is developed in that specific way as it goes through several actualization stages from the developing of model computing elements to the adequate notion of the nature of performing calculations.
The actualization of computing scheme led to the creating of a volume model which was the basis of all following investigations. Six frames have been designed along the working axis for the reducing of boundary conditions influence on computing experiment quantitative results. These frames are located(to show with a pointer) at 0,5 m distance from each other.
The minimization of working mutual influence and boundary conditions on resulting stress and displacement epures were taken into account by a model choosing. By this, initial non-hydrostatic conditions of vertical and horizontal stress components distribution are preserved.
To implement large-scale anchor support there was the fitting out of the integration of mines with the newest drilling equipment (Table 1).
TABLE 1 The acquisition of equipment for anchor fastening of mine workings by the mines of SC “Pavlogradvugilla”
in 2007
TABELA 1 Pozyskanie sprzêtu do mocowania kotw wyrobisk w kopalni SC „Pavlogradvugilla” w 2007 r.
No Mine
Equipment type for anchor fastening
Whole
MQT-120 ZQST-65 STB ZQS-35 I7%S-5/7
1 Ternovskaya 6 2 0 0 2 10
2 Pavlogradskaya 8 3 11
3 Space Heroes 2 2 1 5
4 Blagodatnaya 7 2 3 12
5 Stepnaya 1 2 8 11
6 Yubileynaya 2 1 3
7 Samarskaya 8 1 2 11
8 Dneprovskaya 2 1 1 4
9 West-Dondass 4 1 2 1 8
10 N. I. Stashkov 2 1 3
Total in work of
SC “Pavlogradvugilla” 34 12 18 0 14 78
Taking into consideration difficult mining and geological and mine technical conditions of coal strata waste courses at the SC “Pavlogradvugilla” the task to define efficient fastening parameters was solved taking into account distribution load both in the cross and longitudinal sections of working.
Analytical investigations have shown that anchor strain efforts effect have considerable impact on support stress field change; these researches also revealed sufficient efficiency of support material stress condition running with the help of anchors towards the rising of its carrying capacity.
The equations which allow to define efficient anchors mounting parameters (the coordi- nates of locus and required carrying capacity) subject to mining and geological conditions of working mounting, geometrical and mechanical support parameters have been obtained on the basis of the developed method with the use of correlation and dispersion analysis.
The analysis of analytical and experimental researches let to develop the method of anchor main parameters computing of initial data for the parameters defining of the har- dening which contains rockmass working.
These researches are the basis of wide-scale implementation of the anchor fastening at the mines of SC “Pavlogradvugilla” program (Table 2).
TABLE 2 The results of carrying out the program of anchor fastening at the mines of SC “Pavlogradvugilla” in 2007
TABELA 2 Wyniki realizacji programu mocowania kotw w kopalni SC „Pavlogradvugilla” w 2007 r.
Mine Kind of activity Fastening type
Carrying out [m]
plan for the program anchor
fastening [m]
fact [m]
1 2 3 4 5
Ternovskaya Working fastening
f/a 222 840
anch. 1000 0
total 1222 840
Connections f/à 1000 869
Ternovskaya total on mine 2222 1709
Pavlogradskaya Working fastening
f/a 3885 3466
anch. 0 788
total 3885 4254
Connections f/a 170 347
Pavlogradskaya total on mine 4055 4601
Space Heroes Working fastening
f/a 3280 3320
anch. 1550 0
total 4830 3320
Connections f/a 0 16
Space Heroes total on mine 4830 3336
Table 2 cont.
Tabela 2 cd.
1 2 3 4 5
Blagodatnaya Working fastening
f/a 3115 1923
anch. 225 0
total 3340 1923
Connections f/a 160 59
Blagodatnaya total on mine 3500 1982
Stepnaya Working fastening
f/a 2250 260
anch. 1304 2950
total 3554 3210
Connections f/a 2900 3102
Stepnaya total on mine 6454 6312
Yubileynaya Working fastening
f/a 0 0
anch. 0 0
total 0 0
Connections f/a 480 886
Yubileynaya total on mine 480 886
Samarskaya Working fastening
f/a 1350 587
anch. 1555 1093
total 2905 1680
Connections f/a 1670 1144
Samarskaya total on mine 4575 2824
Dneprovskaya Working fastening
f/a 60 167
anch. 1050 735
total 1110 902
Connections f/a 640 241
Dneprovskaya total on mine 1750 1143
West-Dondass Working fastening
f/a 1290 2206
anch. 0 241
total 1290 2447
Connections f/a 720 91
West-Dondass total on mine 2010 2538
N. I. Stashkov Working fastening
f/a 1800 1661
anch. 0 0
total 1800 1661
Connections f/a 1410 0
N. I. Stashkov total on mine 3210 1661
SC
“Pavlogradvugilla”
Working fastening
f/a 17252 14430
anch. 6684 5807
total 23936 20237
Connections f/a 9150 6755
Total at the SC “Pavlogradvugilla” 33086 26992
Thus, the reasonability of the use of anchor fastening for West Donbass mining and geological conditions was proved during the examination of the task to increase underground mine workings stability with resource-saving technologies of the edge rockmass hardening;
wide-scale implementation of anchor technologies on conditions of the SC “Pavlogra- dvugilla” has been started.
REFERENCES
[1] S h i r o k o v A.P., 1981 – Theory and Practice of Anchor Support Application. M. Nedra, 381 p.
[2] S h i r o k o v A. P., N a y d o v M.I., P e t r o v A.I., L i d e r V.A., 1990 – Anchor Support in Kuzbas.
M. Prometey, 217 p.
[3] B i k o v A.V., 1986 – To Quicken Supports Implementation of Regulating Resistance at Donbass Mines. Mine building 3, p. 3–6.
[4] P r i y m a k I.M., S i g i n E.M., D z y u b e n k o E.F., 1985 – The Tendencies of Mine Workings Anchor Support Improvement. Mine building 9, p. 30.
[5] K l y e v A.P., 1989 – The Experience of Combined Frame-Anchor Support Application. Donetsk: CLNTI of Minugleprom USSR, 4 p.
[6] M o s u n o v V.A., 1981 – Flexible Rod Support. Mining magazine 4, p. 46–47.
[7] B a y k e n j i n M.A., N i k o l a e n k o N.N., 1982 – The carrying Capacity of Anchor Support Flexibility Element. Bulletin Mining magazine 11, p. 25, p. 27.
[8] S o k o l o v N.V., A b r o s i m o v V.M., 1984 – The Results of the New Steel and Polymeric Anchors Testing at the Mines of Norilskiy GMK. Mining magazine 4, p. 39–40.
[9] S i m a n o v i c h G.A., 1982 – The Interaction of Rockmass and Tubular Rods and the Designing of Their Polymers Calculation Method. Thesis of doctoral candidate’s thesis, Dnepropetrovsk, 19 p.
NOWOCZESNE ASPEKTY MOCOWANIA KOTW W ŒRODOWISKU SC „PAVLOGRADVUGILLA”
S ³ o w a k l u c z o w e
Wzmocnienie ska³, kotwy w ska³ach, stabilnoœæ wyrobisk podziemnych
S t r e s z c z e n i e
Sformu³owano g³ówne zasady utrzymania wyrobisk kopalni podziemnych za pomoc¹ alternatywnych tech- nologii poprzez utwardzanie ska³ krawêdziowych i zastosowanie tych technologii dla przeciwdzia³ania ciœnieniu w kopalni.
THE MODERN ASPECTS OF THE ANCHOR FASTENING USE IN THE ENVIRONMENT OF SC “PAVLOGRADVUGILLA”
K e y w o r d s Rock reinforcement, rock anchors, underground workings’ stability
A b s t r a c t
The main principles of underground mine workings maintenance by alternative technologies by the mean of edge rock hardening and the involvement of these technologies to counteract mine pressure are formulated.
