Sinking Operations Research Articles

Proposal of an Algorithm for Choice of a Development System for Operational and Environmental Safety in Mining

In this paper, a method of mathematical modeling for solving the problem of reusing man-made waste from mining and the processing of ores is proposed. The use of intermediate products (man-made waste: tailings of processing plants, rocks from sinking operations and the technical water of mine drainage) in cyclic production presupposes their use as fill material components and placement in the mined-out voids of underground mines. The influence of mining factors on the fill material composition and the parameters of the created fill mass is justified. The results of a practical implementation of the proposed mathematical model are presented, and an algorithm is compiled. Deformation changes and stress concentration are key criteria in the proposed mathematical model. The proposed algorithm allows for the determination of the preferred system of deposit development, and the selection of its parameters and the fill material composition.

The Analysis of the Stress-Strain State of the System “Equipment Complex - Support - Rock Mass” in the Bottomhole Area of the Shaft

The development of new deposits enterprises requires the construction of deep and super deep vertical shafts. The duration of their construction reaches 8 - 10 years with multi-billion capital investments. To reduce the payback period of these costs, it is necessary to develop and implement effective solutions to increase the speed of sinking operations through the wide introduction of brand-new mechanized equipment complexes. In response to the sinking in the bottomhole area of the shaft a complex, the following geotechnological system is being formed: "tunneling system - support - rock mass", the regularities of which require further study. For these purposes, an analytical method for calculating the shaft support can be used in the context of consideration of a planar contact problem at various phases of the system operation. The mutual coordination of individual phases in accordance with the classical concepts of the underground structures mechanics is possible with the help of a correction factor to the magnitude of horizontal stresses in the rock mass. In this paper we developed the algorithm which determines this coefficient, taking into account the influence of the main technological factors: the jack system pressure of the complex and the speed of sinking.

Analytical analysis of the stress-strain state of the system “mechanized equipment complex - support – rock mass” in the bottomhole area of the shaft

The development of new deposits requires the construction of deep and super deep vertical shafts. The duration of their construction reaches 8 - 10 years with multi-billion capital investments. To reduce the payback period of these costs, it is necessary to develop and implement effective solutions to increase the speed of sinking operations through the wide introduction of brand-new mechanized equipment complexes. In response to the sinking in the bottomhole area of the shaft, the following geotechnical system is being formed: “tunnelling system - support - rock mass”, the regularities of which require further study. For these purposes, an analytical method for calculating the shaft support can be used in the context of consideration of a planar contact problem at various phases of the system operation. The mutual coordination of individual phases in accordance with the classical concepts of the underground structures mechanics is possible using a correction factor to the magnitude of horizontal stresses in the rock mass. In this paper, we developed the algorithm which determines this coefficient, taking into account the influence of the main technological factors: the pressure of the jack system of the complex and the speed of sinking.

USING AN INTEGRATED MODEL FOR SHAFT SINKING METHOD SELECTION / KOMPLEKSINIO MODELIO NAUDOJIMAS GRĘŽINIŲ ĮRENGIMO METODUI PARINKTI

Shafts have critical importance in deep mines and underground constructions. There are several traditional and mechanized methods for shaft sinking operations. Using mechanized excavation technique is an applicable alternative to improve project performance, although impose a huge capital cost. There are a number of key parameters for this selection which often are in conflict with each other and decision maker should seek a balance between these parameters. Therefore, shaft sinking method selection is a multi criteria decision making problem. This paper intends to use the combination of analytical hierarchy process and TOPSIS (Technique for Order Performance by Similarity to Ideal Solution) methods under fuzzy environment in order to select a proper shaft sinking method. A real world application is conducted to illustrate the utilization of the model for the shaft sinking problem in Parvadeh Coal Mine. The results show that using raise boring machine is selected as the most appropriate shaft sinking method for this mine. Santrauka Gręžiniai yra labai svarbūs giliose šachtose ir požeminėse konstrukcijose. Gręžiniai įrengiami keliais tradiciniais ir mechanizuotais metodais. Mechanizuotos žemės kasimo technologijos yra galima alternatyva, gerinanti projekto įgyvendinimą, tačiau tam reikia didžiulių kapitalo išlaidų. Pasirinkimui įtaką daro daug tarpusavyje nederančių rodiklių, tad sprendimą priimantis asmuo turi rasti balansą tarp jų. Todėl grųžiniu įrengimo metodo parinkimas yra daugiakriterinių sprendimų priėmimo problemą. Šiame straipsnyje naudojama analitinio hierarchinio proceso ir TOPSIS (artumo idealiajam taškui) metodo neraiškioje aplinkoje kombinacija tinkamam gręžinių įrengimo metodui parinkti. Modelio naudojimo atvejis iliustruojamas realiu pavyzdžiu, sprendžiant gręžinių irengimo problemą Parvadeh anglių kasykloje. Rezultatai rodo, kad keliamasis gręžimo įrenginys parenkamas kaip tinkamiausias gręžiniams įrengti šioje kasykloje.

Shaft sinking risk analysis through the integration of borehole radar and acoustic televiewer data in deep geotechnical boreholes

The 2.06 Ga Bushveld Igneous Complex of South Africa is the world?s largest layered igneous intrusion. Situated to the north of the Johannesburg, it extends ~450 km from east to west and ~300 km north to south (Simmat et al., 2006), and has a maximum thickness of ~8 km. It is estimated to contain over half the world?s Platinum Group Element (PGE) resources (Cawthorn, 1999). The two PGE-bearing chromitite layers in the Bushveld Complex, the Merensky Reef and the UG2, occur within pyroxenites of the Critical Zone, show high lateral continuity and commonly dip at relatively shallow angles (2°-20°) towards the centre of the complex. These are overlain by a succession of norite and gabbronorite formations of the Main Zone, representing a more mafic phase of the intrusion. The project area is the location of a planned new Anglo Platinum mine on the western limb of the Bushveld, south of the Pilanesberg Alkaline Complex, a later volcanic event. Major capital investment is required to sink the twin shafts, accessing the underground platinum reefs from ~700 m depth. Due to the proximity to the Pilanesberg, dykes and faults are pervasive throughout the deposit. Several dyke varieties occur and these differ in composition, texture and orientation, and consequently represent different geotechnical hazards. Dolerite dykes tend to be hard and competent with similar rock strength properties to that of the surrounding Bushveld rocks, and are not expected to represent significant geotechnical problems. Lamprophyre dykes, however, are often soft, weather easily when exposed and demonstrate significant contrast in rock strength properties to the Bushveld rocks. Shaft geotechnical boreholes were drilled along the two proposed shaft axes and were logged with a suite of geophysical tools to detect potentially hazardous structures that may influence shaft sinking operations. This paper examines the integration of borehole radar (BHR) and acoustic televiewer (ATV) data down the proposed main- and ventilation shaft positions.

Rotating Curvilinear Tools for EDM of Polygonal Shapes with Sharp Corners

Flushing of the inter-electrode gap is of critical importance in the performance of electrical discharge sinking operations. When the provision of flushing holes in the tool or the workpiece is impractical, effective flushing is best realized by inducing a relative motion between the electrodes. This paper relates to a novel application inspired by the kinematics of a Reuleaux Triangle that facilitates flushing through synchronous orbiting of a rotating curvilinear tool. This innovative scheme enables the machining of regular as well as non-regular polygonal shapes with sharp corners. Experimental results from implementing this concept on a 4-axis CNC EDM machine tool are presented.

Effects of blast induced vibrations on the fresh concrete lining of a shaft

During shaft excavation, blast induced vibrations can cause micro-cracks in the fresh concrete lining and decrease its strength. The traditional method to reduce the vibration effect is to control the scale of blasting and apply temporary support to protect the fresh concrete. Recent research was conducted to study the effects of the blast induced vibration on the fresh concrete. Shaft sinking operations (drilling, blasting and concrete lining) were simulated in a laboratory model. Additives of triethanolamine - TEA (N(C2H4OH)3) and sodium chloride (NaCL) in varying proportions were added to the concrete lining to increase the early strength. Vibration was generated by small scale blasting. The experimental results show that the blast induced vibration has negative and positive effects on the strength of the fresh concrete depending on the curing time at blasting. Vibration can increase the strength within the first 1-2 days. After that period, vibration can cause cracks in the fresh concrete and reduce the strength. Still later, it has no more effect. The time windows vary with the magnitude of vibration and the strength of the concrete at the time of blasting. It was also found that both additives increased the early strength of concrete lining and expanded the time windows. These results indicate that proper timing of blasting and use of additives can change the negative effect of the blast induced vibration into a positive effect and increase the strength of a concrete lining. (A) Reprinted with permission from Elsevier.

Support requirements during shaft sinking operations at 10 shaft Vaal reefs exploration & Mining Co Ltd : Harris, B A; Akermann, K A Proc Symposium on Rock Instability Problems in Mine Shafts, Potchefstroom, 10 May 1990P1–5. Publ Marshalltown: SANGORM, 1990

Support requirements during shaft sinking operations at 10 shaft Vaal reefs exploration & Mining Co Ltd : Harris, B A; Akermann, K A Proc Symposium on Rock Instability Problems in Mine Shafts, Potchefstroom, 10 May 1990P1–5. Publ Marshalltown: SANGORM, 1990

Shaft sinking and mid-shaft loading operations at H.J. Joel gold mine, Orange Free State, South Africa : Rhodes, K A Min EngrV148, N323, Aug 1988, P89–95

Shaft sinking and mid-shaft loading operations at H.J. Joel gold mine, Orange Free State, South Africa : Rhodes, K A Min EngrV148, N323, Aug 1988, P89–95

Sinking of the deepest shaft in Turkey

This paper describes the sinking of New Kozlu Shaft in the Zonguldak Coalfield, Turkey. This 6.5 m diameter shaft, with its final depth of 913 m has become the deepest shaft sunk in the country. The construction which lasted about eleven and a half years is reviewed in two separate sinking stages carried out by the coal company and a contracting firm. Also, comparisons of the equipment and sinking operations in these stages are given.

Aspects of advanced grouting during shaft sinking in South Africa

Fixed costs for shaft sinking operations are extremely high, therefore precautions must be taken to avoid unproductive standing time of the shaft sinking crew. Water in-rushes or unconsolidated grounds sometimes cause stoppages to sinking operations because the sidewalls must be sealed or stabilised. Pregrouting can to a large extent avoid such delays. The paper describes ways and means how to execute pregrouting under varying conditions and draws attention to problems which may be encountered. The author concludes that the cost for preventive grouting operations are small compared with the overall expenses of shaft sinking operations and the cost of unproductive standing time.

MARINE AND OTHER FOSSILS IN THE YORKSHIRE COAL MEASURES ABOVE THE BARNSLEY SEAM, AS SEEN AT THE BENTLEY COLLIERY, NEAR DONCASTER

( Read 4 th November , 1909. Manuscript received 2 nd December , 1909.) During the sinking operations to the Barnsley seam at the Bentley Colliery, near Doncaster, the opportunity was taken of examining the material brought to the surface, with the result that the accompanying section (p. 77) and lists of fossils (pp. 78–81) can now be put on record. These particulars, it is suggested, will be found useful, in conjunction with those from Brodsworth (Proc. Yorks. Geol. Soc., 1908, pp. 321–333), in their bearing on the exploration of the concealed coalfield east of Doncaster. They have already proved very helpful in locating position. The situation of the Bentley Colliery is 2½ miles north of Doncaster and 2½ miles east of Brodsworth Colliery. The Barnsley Coal was 9 feet 5 inches thick at Brodsworth, and was reached at a depth of 1,645 feet below Ordnance Datum. At Bentley it was 9 feet 8 inches thick, its depth below Ordnance Datum being 1,842 feet. The description of the seam at Bentley is as follows :— The marine shells at Bentley, which numbered 38 species, were found in four bands, the comparison with Brodsworth (21 species), in regard to positions, being as under :— | | | | ft. | in. | |:--------- | - | - | --- | --- | | Soft Coal | … | … | 4 | 1 | | Parting | … | … | | 4½ | | Hard Coal | | … | 2 | 9 | | Soft Coal | … | … | 2 | 5½ | | | | | 9 | 8 | | | | | | Marine Bands, height in feet above Barnsley Coal. | |:----------------------- | | | - | ------------------------------------------------- | - | | | | | | Bentley. | | Brodsworth. | | M.B. above Shafton Coal | | | … | 1,131 | … | 1,157 | | M.B with Limestone Base | | | … | 675½ | | |