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Dimension-Stone Quarrying Optimization through Integrated Modelling between Joint Sets and Cutting Grid: a Case Study at Tan Long Dimension Stone Quarry in Southcentral Coastal Province of Binh Dinh

Pham Van Viet, Nguyen Anh Tuan, Pham Van Hoa, Tran Dinh Bao

Inżynieria Mineralna

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2023

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no. 2, vol. 1

239--248

EN

Dimension-stone quarrying optimization is significantly important to increase the recovery ratio of dimension stone and to reduce the cutting cost. Due to fracture-existed rock mass, in the mining operation block size and mining direction influences to the recovery ratio and the cutting cost. Therefore, the paper suggests the quarrying optimization for dimension stone to obtain the highest recovery ratio and the lowest cutting cost, based on optimizing block size and mining direction to get a cutting grid of dimension stone. Through developing an integrated modelling between joint set modelling and cutting grid modelling, intact blocks and fractured blocks were generated. From this, block statistics were conducted to get the maximum recovery ratio of dimension stone and the minimum cutting rate between the cutting area and the recovered block volume, which helps to choose an optimizing block size and mining direction. The research was carried out at Tan Long dimension stone quarry where a block size (0.9m x 0.6m x 1.35m) and a mining direction paralleling to joint set 1 will ensure the highest recovery ratio of 13.87% and the lowest cutting rate of 25 m2/m3.

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Investigating the effectiveness of a ground support system implemented on Block A: a case study of Southern Africa metalliferous mine

Manyelo Kamogelo, Kolapo Peter

Journal of Sustainable Mining

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2022

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Vol. 21, iss. 1

15--26

EN

This study aims to investigate the effectiveness of the ground support systems that are planned to be implemented on Block A, which will be excavated through the Marikana fault zone. The block of ground being prepared for mining has been physically affected by the presence of the Marikana fault and is therefore geomechanically and geotechnically weaker than the normal stoping conditions on the rest of the shaft. Joint mapping conducted in Block A raiselines indicated that there is a high concentration of shallow dipping joints which are dipping in opposite directions. Such conditions present special challenges in the planned excavations because they can lead to sudden and uncontrolled collapses unless appropriate action is taken to mitigate such instances. The orientation of joint sets aid the formation of keyblocks, which can collapse provided their weight exceeds the support load bearing capacity or if they are located in between support units. Therefore, stoping in the Marikana fault zone requires a more intensive support with a higher than normal support resistance. The existing ground control strategies, the processes, tools, techniques, and methods that are currently being used for support design were investigated and incorporated into the new system where applicable.

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Pomiary i estymacja wskaźników zagęszczenia nieciągłości w kołowych oknach pomiarowych

Jakubowski J.

Górnictwo i Geoinżynieria

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2010

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R. 34, z. 2

315-324

PL

Pomiary nieciągłości, estymacja wskaźników zagęszczenia nieciągłości i ich interpretacja są istotne z punktu widzenia budowy modeli oraz przebiegu i wyników geomechanicznych symulacji nieciągłego masywu skalnego. W szczególności wskaźniki zagęszczenia nieciągłości są ważnymi parametrami statystycznych modeli sieci nieciągłości, na których opierają się geomechaniczne symulacje stochastyczne mechaniki skał. Istotny postęp praktycznych metod estymacji parametrów sieci nieciągłości nastąpił niedawno dzięki pracom teoretycznym Mauldona (oraz niezależnie Zhanga i Einsteina) dotyczącym pomiarów i estymacji wskaźników zagęszczenia nieciągłości w kołowych oknach pomiarowych. Nowe estymatory opierają się na zliczeniach końców śladów nieciągłości bez konieczności przeprowadzania trudniejszego pomiaru ich długości, nie są obciążone błędem cenzurowania ani błędem długości, są niezależne od orientacji śladów nieciągłości i mają bardzo prostą postać.

EN

Quantitative descriptions of joint sets and their interpretation are significant for discontinuous rock mass simulation models and results. Joint sets density, intensity and are among the major ones. They are also important parameters of discontinuity network statistical models and discontinuous rock mass stochastic simulations, including geomechanical simulations. A significant advance in jointed rock mass parameters survey and estimation methods has been achieved recently. Mauldon (independently by Zhang and Einstein) proposed a method for mean trace length and trace density estimation in circular sampling window. New estimators are based on joint trace endpoints counts so avoid trace length measurement, are not biased by censoring and length bias and are not dependent on traces orientation. They have been presented and discussed in the paper.