Cost estimates as a design tool — the impact of mine design on ventilation costs for a variety of underground mining scenarios

Author(s):  
Scott Stebbins
1996 ◽  
Vol 33 (3) ◽  
pp. 431-439 ◽  
Author(s):  
Mark S Diederichs ◽  
Peter K Kaiser

Modern underground mining methods often call for the excavation of large, often unsupported voids called stopes. In many cases, these are nonentry stopes, with the removal of broken rock (mucking) performed by remote control. With the risk to human safety thus reduced, stability concerns within the stopes are primarily driven by the economics of unplanned overbreak and waste rock dilution of the mined ore. In this context, it is appropriate to speak of acceptable risks of instability and to optimize design by balancing risk costes with productivity potential. Larger individual stopes generally increase productivity while reducing stability. The modified stability graph is a popular empirical mine design tool that has been calibrated to provide discrete recommendations for maximum stope dimensions based on a rock quality index. It seems appropriate to extend the method to account for variability in the calibration data and also for variability in each new set of input parameters. A risk template and associated probabilistic techniques are proposed to supplement the discrete design limits currently established. Key words: risk, mining, stability, design, emperical.


Energies ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4658
Author(s):  
Artur Guzy ◽  
Wojciech T. Witkowski

Land subsidence caused by groundwater withdrawal induced by mining is a relatively unknown phenomenon. This is primarily due to the small scale of such movements compared to the land subsidence caused by deposit extraction. Nonetheless, the environmental impact of drainage-related land subsidence remains underestimated. The research was carried out in the “Bogdanka” coal mine in Poland. First, the historical impact of mining on land subsidence and groundwater head changes was investigated. The outcomes of these studies were used to construct the influence method model. With field data, our model was successfully calibrated and validated. Finally, it was used for land subsidence estimation for 2030. As per the findings, the field of mining exploitation has the greatest land subsidence. In 2014, the maximum value of the phenomenon was 0.313 cm. However, this value will reach 0.364 m by 2030. The spatial extent of land subsidence caused by mining-induced drainage extends up to 20 km beyond the mining area’s boundaries. The presented model provided land subsidence patterns without the need for a complex numerical subsidence model. As a result, the method presented can be effectively used for land subsidence regulation plans considering the impact of mining on the aquifer system.


2014 ◽  
Vol 54 (9-10) ◽  
pp. 1655-1660 ◽  
Author(s):  
N.C. Sintamarean ◽  
H. Wang ◽  
F. Blaabjerg ◽  
P.de P. Rimmen

2015 ◽  
Vol 36 (2) ◽  
pp. 17-28
Author(s):  
Lucyna Florkowska ◽  
Jan Walaszczyk

Abstract Numerical modelling is an important tool used to analyse various aspects of the impact of underground mining on existing and planned buildings. The interaction between the building and the soil is a complex matter and in many cases a numerical simulation is the only way of making calculations which will take into consideration the co–existence of a number of factors which have a significant influence on the solution. The complexity of the matter also makes it a difficult task to elaborate a proper mathematical model – it requires both a thorough knowledge of geologic conditions of the subsoil and the structural characteristics of the building. This paper discusses the most important problems related to the construction of a mathematical model of a building-mining subsoil system. These problems have been collected on the basis of many years of experience the authors have in observing the surveying and tensometric deformations of the rock–mass and buildings as well as in mathematical and numerical modelling of the observed processes.


2021 ◽  
Author(s):  
Apurva Patel ◽  
Joshua D. Summers ◽  
Akash Patel ◽  
James L. Mathieson ◽  
Michael P. Sbarra ◽  
...  

Abstract While fundamentals of DFMA are widely accepted and used in the engineering design community, many CAD environments lack tools that address manufacturing concerns and provide rapid feedback to designers about manufacturing impacts of their design choices. This paper presents an experiment-based testing and validation of a rapid feedback tool that provides users a history-based prediction of manufacturing time based on the current state of the design. A between-subjects experiment is designed to evaluate the impact of the tool on design outcomes based on modeling time, part mass, and manufacturing time. Participants in the study included mechanical engineering graduate and undergraduate students with at least one semester of experience using SolidWorks. The experiment included three different design activities and three different conditions of the design tool. Participants completed up to three sessions with different experimental conditions. Analysis of the data collected shows that use of the design tool results in a small but nonsignificant increase in modeling time. Moreover, use of the tool results in reduced part mass on average, as well as in a within-subject comparison. Tool use reduced manufacturing time in open ended activities, but increased manufacturing time when activities focus more on mass-reduction. Participant feedback suggests that the tool helped guide their material removal actions by showing the impact on manufacturing time. Finally, potential improvements and future expansions of the tool are discussed.


2018 ◽  
Vol 174 ◽  
pp. 04005
Author(s):  
Daniel Przywara ◽  
Adam Rak

Records of the national, average pay rates in the construction industry, at quarterly intervals, allow cost - planning departments of contractors and investment services to assess current market conditions in the construction industry. Price quarterly publications, such as Sekocenbud and Intercenbud, contain important information, enabling production preparation departments to prepare a comparison of the production in-house labor rates with the market production labor rates. The article attempts to analyze the economic situation of domestic construction production in the years 2010-2016 based on the emerging price trends of the of labor cost estimates in this period, taking into account the impact of seasonal construction services. In "Polish cost estimates standards", the labor cost estimate rate is present in one form: the net labor cost estimate rate, which fully corresponds to the rate defined in calculation formulas. The rates of labor cost estimates, in individual regions of Poland, are shaped according to the presented market situations. This clearly is reflected in the periodic (quarterly) regional records of labor rates in the Sekocenbud system. The Act on prices of July 5, 2001 does not contain any normative regulations regarding the methods of cost estimation of construction works. The necessity to remain competitive forces large construction corporations to use a subcontracting system, involving several or even several dozen smaller, specialized in a narrow range of works, business entities in which labor costs are definitely lower, because they are reduced by a lower value of internal costs.


Author(s):  
Ryan S. Hutcheson ◽  
Daniel A. McAdams ◽  
Robert B. Stone ◽  
Irem Y. Tumer

The Function-based Behavioral Modeling (FBBM) design tool was introduced in prior work as a means of using formal functional modeling as the foundation for creating detailed mathematical models of system behavior. The overall objective of this work is to create a framework for partitioning modeling efforts into functional elements and promoting model storage and re-use through the use of functional models. In prior work, the FBBM method was introduced to model the complete vehicle dynamics of a Formula SAE racecar, highlighting the representation of functionality and the development of behavioral models. The objective of the work presented in the current paper is to demonstrate the ability to incorporate models of varying fidelity within a function-based behavioral model of a complex system. Additionally, the impact of model fidelity on the model’s predictions is addressed. A previously developed model is used as a foundation for developing the necessary new models and illustrating the impact of model fidelity on performance predictions when selecting a tire during early design. The results illustrate that the FBBM framework allows models of varying fidelity to be quickly made and their effect on predicted performance to be measured in order to assist critical early design choices.


Author(s):  
Cyril Picard ◽  
Jürg Schiffmann

Abstract Automated design tools are seldom used in industry. Their potential, however, is high, especially in companies mostly active in variant design, where custom tools could help cut down development time in the early stages. The design of geared electro-mechanical actuators for the automotive industry is such a case. These actuators are simple examples of coupled multi-disciplinary systems that can be hard to design, since they need to follow strict specifications in terms of performance and packaging. This paper presents an automated design and optimization tool tailored for such systems based on an integrated modeling approach, multi-objective optimization and an interactive reporting tool. The focus is set on the impact of system-level constraints on the usability by industry of the generated designs. In two case studies, the tool is able to find competitive actuator candidates that are cheaper (−3.6% and −11%) and more compact than similar existing products in less than an hour on a state-of-the-art laptop computer. More powerful options or actuators using different technologies have also been proposed. Compared to optimizations done without system-level constraints, the generated actuators are immediately usable by engineers to get accurate insights into the design problem and promote informed decision-making.


Energies ◽  
2020 ◽  
Vol 13 (11) ◽  
pp. 2998 ◽  
Author(s):  
Krzysztof Skrzypkowski

The article presents the impact of geological and mining factors on the stability of room excavations in the Legnica-Głogów Copper District (LGOM) in Poland. In underground mining, the primary task of bolting of mining excavations is to ensure their stability as an essential condition of work safety. Appreciating the role and importance of the rock bolting in Polish ore mining; rock bolt load sensors were designed, manufactured and tested under laboratory conditions. The purpose of the research was to characterize the sensors and determine the elastic range of the bearing plate, which are an integral part of the sensor. The sensors have been verified in industrial conditions. The tests were carried out in the underground copper ore mine in Poland. Three rooms in the exploitation field were selected for testing, where exploitation was carried out at a depth of 809–820 m below the ground surface with the application of room and pillar with roof deflection and maintaining the central part of the field. The exploitation field included 60 rooms and pillars. The effectiveness of the mechanical load sensor of the expansion rock bolt support has been experimentally confirmed. Based on mine research, it was found that the largest increases in the load of the rock bolting, vertical stress and convergence occur in the middle of the mining field.


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