Browsing by Subject "mining support"

Now showing 1 - 7 of 7

Access status: Open Access ,
Analiza pracy złącza ciernego odrzwi obudowy górniczej przy osiowym ściskaniu i statycznym zginaniu
(Wydawnictwa AGH, 2010) Brodny, Jarosław
In the article friction joints stress analysis of steel frame of road support with axial compression and the static bending are presented. Analyzed joint consisting of two straight sections of Profile V29 combined two types SDO29 stirrups. With static bending two cases of load joint were examined. In the first loading force acted on the joint accordance with PN-91/G-15000/11 through traverse, in the second case the force acts directly in the middle of the connector according to DIN 21530-4-2003-05. The results of position experiments and numerical analysis, carried out by finite elements method, were presented. On the basis of the analysis characteristics of connector work and the most exposed places of particular elements of friction joint have been determined. Presented numerical models are creating great simulation potential in the changeability of the value and the load speed as well as structural changes in the analyzed joints.
Access status: Open Access ,
Możliwości zastosowania siatek stalowych w warunkach zagrożeń dynamicznych
(2007) Cała, Marek; Roth, Andrea
This paper deals with loading of the support under rockburst hazard. Such a support should be able to absorb the kinetic energy of the rock blocks ejected to mining underground opening. The high-tensile Tecco mesh, which is made of steel wire with tensile strength of 1770 MPa was described. The Tecco mesh was tested in Australia to determine the force-deflection curve and the breaking load with different bolt patterns and wire diameters. Several numerical calculations (calibrated with laboratory tests) were also performed in Switzerland. Laboratory experiments and numerical calculations showed that Tecco mesh was able to absorb energy from 33,6 $kN/m^{2}$ (Tecco S95/3, wire diameter 3 mm) to 50 $kN/m^{2}$ (Tecco S95/4, wire diameter 4 mm). These values are over a dozen times higher than for welded mesh or chain link mesh. The application of high-tensile steel mesh in mining openings in rockburst prone mines should be seriously considered.
Access status: Open Access ,
Multi-criterion analysis of factors affecting maintenance of roadways
(2012) Małkowski, Piotr; Majcherczyk, Tadeusz; Niedbalski, Zbigniew
W artykule przeanalizowano czynniki wpływające na możliwość utrzymania wyrobisk korytarzowych w polskich kopalniach węgla. Autorzy podzieli czynniki na trzy grupy: naturalne, górnicze i techniczne oraz dwie podgrupy: właściwości geomechaniczne i rodzaj obudowy. Analizę wykonano w oparciu o metodę AHP, na podstawie ankiet wypełnionych przez ekspertów z kopalń i jednostek naukowo-badawczych. Wybrana metodyka pozwoliła na określenie hierarchii znaczenia wybranych czynników dla utrzymania wyrobisk, a także wskazania czynników uniwersalnych, czyli istotnych w warunkach każdej kopalni i czynników lokalnych, istotnych w określonych warunkach górniczo-geologicznych.
Access status: Open Access ,
Wpływ obciążenia dynamicznego na charakterystykę pracy stosowanego w górniczej obudowie podatnej złącza ciernego z klinem oporowym
(Wydawnictwa AGH, 2011) Brodny, Jarosław
A new design solution of a joint has been developed using an additional element such as a thrust wedge to improve the working characteristic of the friction used in yielding supports. The article presents the results of stand tests for the new joint design subject to a dynamic load. The source of dynamic loading was impact mass falling from a specific height. A working characteristic of a friction joint was determined (relationship between the force transmitted by the joint according to time), the characteristics of variations in the value of axial forces in the clamp joints and the displacement of the selected friction joint components. The results obtained indicate that the use of a thrust wedge in the friction joint design improves its working parameters.
Access status: Open Access ,
Wpływ obciążenia dynamicznego na parametry pracy złącza ciernego
(Wydawnictwa AGH, 2011) Brodny, Jarosław
The article presents the results of stand tests for friction joints under a dynamic load. The tests consisted of exerting an axial load (compression) on the friction joint on which a traverse was placed with a mass freely falling from a specific height. The dynamic characteristics of a friction joint's work were identified based on the tests carried out. The characteristics determine a variance in the value of the force transmitted by a friction joint during a dynamic load according to time. Variances in the value of axial forces in the clamps joints were also registered during the tests. The displacements of a friction joint's elements were recorded with a highspeed camera which also enabled to determine their speeds and accelerations. The tests results presented should be used in operating, designing and selecting a yield support for the conditions of a dynamic load hazard.
Access status: Open Access ,
Wstępna analiza pracy połączenia śrubowego w złączu ciernym
(Wydawnictwa AGH, 2010) Brodny, Jarosław
In the article are presented the results of the stress analysis of the screws stirrups work in friction joint steel arch mining support. Analysis covered the determination of axial forces acting in the stirrup screws connector tighten by initial bending torque. Forces have been designated on the basis of position researches and numerical analysis of connectors work subjected to axial compression and static bending. Researches and analysis have been carried out for the joint consisting of two straight sections of Profile V29 combined two stirrups in accordance with SDO29 type PN-91/G-15000/11 and DIN 21530-4-2003-05.
Access status: Open Access ,
Wzmacnianie obudowy wyrobisk korytarzowych w złożonych warunkach górniczo-geologicznych
(Wydawnictwa AGH, 2010) Majcherczyk, Tadeusz; Niedbalski, Zbigniew; Małkowski, Piotr
Designing optimal support for underground headings in hard coal mines, particularly for the conditions with intensified rock pressure, is a serious challenge for engineers and coal companies. Not only the already-existing technological practices are continually improving but also numerous innovative solutions related to such problems are implemented. The paper presents an analysis of heading support work. The applied support scheme consisted of steel yielding support reinforced with strand bolts and crown runners. Coal-mine research findings indicated the changes around the analyzed headings, during exploitation. It was carried on at considerable depths and in the areas of hard mining and geological conditions. The results of the field research and achieved experience provided a basis for designing a drift in combined standing-and-roof-bolting support. Such a solution was elaborated with the use of numerical methods. The drift is to became the main opening working at the depth of almost 1300 m.