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Constructing musical spaces beyond technological Eden a participative initiative for musical interface development based in the Peruvian context /Lopez Ramirez-Gaston, Jose Ignacio. January 2008 (has links)
Thesis (Ph. D.)--University of California, San Diego, 2008. / Title from first page of PDF file (viewed Jan. 12, 2009). Available via ProQuest Digital Dissertations. Vita. Includes bibliographical references: P. 111-117.
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Επαγόμενες υπερτάσεις από κεραυνούς σε υπόγειους μεταλλικούς αγωγούςΠετράτου, Παναγιώτα 29 August 2011 (has links)
Ο κεραυνός είναι μία ηλεκτρική εκκένωση ατμοσφαιρικής προέλευσης απλή ή πολλαπλή μεταξύ νέφους και γης. Αποτελεί ένα φυσικό φαινόμενο με επικίνδυνα αποτελέσματα για την ασφάλεια των ανθρώπων, των κτιρίων και των ηλεκτρικών συστημάτων. Αν και είναι τόσο παλιό όσο και ο πλανήτης μας, μπόρεσε να εξηγηθεί μόνο κατά τους τελευταίους δύο αιώνες. Από το 1753 όπου ο B. Franklin απέδειξε την ύπαρξη ατμοσφαιρικού ηλεκτρισμού μέχρι σήμερα, με πολλές μοντέρνες μεθόδους και πειράματα έχει αποκτηθεί αρκετή γνώση επάνω στο φαινόμενο αυτό και κατά συνέπεια έχουν αναπτυχθεί αρκετά ασφαλείς τρόποι προστασίας από τους κινδύνους ενός κεραυνού.
Όταν ένας κεραυνός πλήξει το έδαφος, το ρεύμα του εκφορτίζεται στη μάζα της γης. Η τελική κατανομή του ρεύματος εξαρτάται κατά πολύ από την ανομοιογένεια του εδάφους, επειδή το ρεύμα θα ρέει όπου είναι πιο εύκολο δηλαδή κατά μήκος αγώγιμων κοιτασμάτων ή γεωλογικών σφαλμάτων που είναι διάχυτα σε έδαφος με μικρή αγωγιμότητα. Εξ αιτίας αυτού του γεγονότος, όταν υπάρχει ένας μεταλλικός αγωγός μεγάλου μήκους , η μεταλλική του επιφάνεια θα βραχυκυκλώσει τμήμα του ηλεκτρικού πεδίου που δημιουργείται στο έδαφος από πλήγμα κεραυνού. Το ρεύμα του κεραυνού συγκεντρώνεται στην επιφάνεια του αγωγού, ενώ το βάθος διείσδυσης του κεραυνού είναι κυρίως συνάρτηση της επικρατούσας ειδικής αντίστασης του εδάφους.
Επίσης, ένας κεραυνός που πλήττει το έδαφος παράγει ένα μεταβαλλόμενο ηλεκτρομαγνητικό πεδίο, το οποίο επάγει τάσεις σημαντικού ύψους στους υπόγειους μεταλλικούς αγωγούς που βρίσκονται σε γειτνιάζουσα περιοχή με το σημείο του πλήγματος, οι οποίες θα καταπονήσουν τους υπόγειους αγωγούς προκαλώντας ακαριαία καταστροφή ή ισχυρή καταπόνηση οδηγώντας σε βαθμιαία φθορά.
Σκοπός αυτής της διπλωματικής εργασίας είναι η μελέτη και η ανάλυση των επαγόμενων υπερτάσεων οι οποίες εμφανίζονται σε υπόγειους μεταλλικούς αγωγούς λόγω των κεραυνικών πληγμάτων. Για αυτούς τους λόγους κάνουμε μια εκτενή ανάλυση της δημιουργίας κεραυνών καθώς και των επιπτώσεών τους στη γήινη επιφάνεια. Ακόμη γίνεται αναφορά στο είδος των υπερτάσεων που δημιουργούνται από τους κεραυνούς καθώς και στο τρόπο με τον οποίο προστατεύονται οι υπόγειοι αγωγοί από τις υπερτάσεις. Στη συνέχεια με την χρήση του λογισμικού ATP-EMTP γίνεται ανάλυση των υπερτάσεων που δημιουργούνται στους αγωγούς όταν ένας κεραυνός πλήξει μια γειτονική γραμμή μεταφοράς. Η εργασία ολοκληρώθηκε με παρατηρήσεις επάνω στα αποτελέσματα των εξομοιώσεων. / Lightning is an electrical discharge atmospheric origin single or multiple
between cloud and earth. It is a natural phenomenon with dangerous results for the safety of people, buildings and electrical systems. Although it is as old as our planet, could be explained only in the last two centuries. Since 1753 when the B. Franklin proved the existence of atmospheric electricity up to today, with many modern methods and experiments has been acquired enough knowledge on this phenomenon and accordingly have been developed several safe ways to protect against the risks of lightning.
When a lightning struck the ground, his current discharged to the mass of earth. The final distribution of current depends by far from the heterogeneity of the soil, because the current flows where it is easier, that is to say at length of conductive deposits or geological faults that are diffuse in the soil with low conductivity. Because of this, when there is a long metal pipeline, his metal surface will fuse department of electric field that is created in the ground by hurt of lightning. The lightning current is concentrated on the surface of the pipeline, while the depth of infiltration of lightning is mainly a function of the prevailing soil resistivity.
Also, a lightning that affects the ground produces a altered electromagnetic field, which induces voltages considerable amount of underground metallic pipelines located in nearby locations to point to the shock, which stresses the underground pipes, causing immediate destruction or high stress leading to a gradual deterioration.
Aim of this work is the study and analysis of induced voltages that occur in underground metallic pipelines due to lightning strikes. For these reasons, we do an extensive analysis of the creation of lightning and its impact on the earth's surface. Also refers to the type of over voltages caused by lightning and the way protect underground pipes from the over voltages. Afterwards, with the use of ATP-EMTP software becomes analysis of the over voltages that are created in the pipelines when a lightning struck a nearby transmission line. The work was completed with observations on the results of the simulation.
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Υπολογισμός υπερτάσεων λόγω κεραυνών σε συνδέσεις εναέριων γραμμών - υπόγειων καλωδίωνΔεληγιάννης, Αναστάσιος 19 July 2012 (has links)
Σκοπός της παρούσας διπλωματικής εργασίας είναι η μελέτη της συμπεριφοράς εναέριων γραμμών και υπόγειων καλωδίων μεταφοράς υψηλής τάσης έναντι κεραυνών. Για την εξυπηρέτηση του σκοπού αυτού, γίνεται προσομοίωση ενός υβριδικού δικτύου, αποτελούμενου τόσο από εναέριες γραμμές μεταφοράς όσο και από υπόγεια καλώδια, και μελέτη των μεταβατικών υπερτάσεων που εμφανίζονται σε αυτό λόγω κεραυνικών πληγμάτων σε έναν από τους αγωγούς προστασίας του τερματικού πυλώνα, όπου πραγματοποιείται η διασύνδεση εναέριας γραμμής-υπόγειου καλωδίου.
Στο πρώτο κεφάλαιο παρατίθενται κάποια θεωρητικά στοιχεία σχετικά με τις ατμοσφαιρικές υπερτάσεις. Αναλύονται τα είδη των κεραυνών, οι βασικές παράμετροι και τα κύρια χαρακτηριστικά τους. Επιπλέον, περιγράφονται οι επιπτώσεις από κεραυνικά πλήγματα και ο τρόπος εύρεσης της συχνότητας με την οποία συμβαίνουν κεραυνοί ανά περιοχή.
Στο δεύτερο κεφάλαιο γίνεται μία εισαγωγή στα Συστήματα Ηλεκτρικής Ενέργειας και αναπτύσσονται τα βασικά στοιχεία των εναέριων γραμμών και των υπόγειων καλωδίων μεταφοράς ηλεκτρικής ενέργειας. Επίσης, πραγματοποιείται μία σύγκριση αυτών των δύο τρόπων μεταφοράς ηλεκτρικής ενέργειας, παρουσιάζοντας τα θετικά και αρνητικά στοιχεία καθενός από αυτούς.
Στο τρίτο κεφάλαιο εξετάζονται τα είδη σφαλμάτων και τα αίτια δημιουργίας αυτών στις γραμμές μεταφοράς ηλεκτρικής ενέργειας. Επιπλέον, δίνονται κάποια βασικά χαρακτηριστικά για την κυματομορφή του κεραυνικού ρεύματος.
Στο τέταρτο κεφάλαιο αναλύεται η μόνωση και η προστασία τόσο των εναέριων γραμμών όσο και των υπόγειων καλωδίων έναντι κεραυνικών πληγμάτων. Εξετάζονται ακόμα οι μηχανισμοί που εγείρουν υπερτάσεις στη γραμμή μεταφοράς. Έπειτα, για τον καθορισμό της θέσης των αγωγών προστασίας της γραμμής, περιγράφονται οι μέθοδοι της μέγιστης γωνίας αλλά και η ηλεκτρογεωμετρική μέθοδος.
Στο πέμπτο κεφάλαιο αναπτύσσονται τα επιμέρους στοιχεία του υπολογιστικού προγράμματος ATP-EMTP, το οποίο θα αποτελέσει το μέσο εξομοίωσης για την παρούσα εργασία. Αναφέρονται τα σημεία υπεροχής και η καταλληλότητά του για τέτοιου είδους αναλύσεις και παρουσιάζονται τα επιμέρους υποπρογράμματα από τα οποία αποτελείται. Ιδιαίτερη έμφαση δίνεται στο ATPDraw, το οποίο είναι το κύριο όργανο της εξομοίωσης.
Στο έκτο κεφάλαιο περιγράφεται αναλυτικά το υβριδικό δίκτυο μεταφοράς υψηλής τάσης που χρησιμοποιείται στην εξομοίωση και αναλύονται τα στοιχεία που το αποτελούν, δηλαδή οι εναέριες γραμμές και τα υπόγεια καλώδια. Επιπλέον, παρουσιάζονται τα αποτελέσματα των εξομοιώσεων και οι γραφικές παραστάσεις των υπερτάσεων στα διάφορα σημεία του κυκλώματος, εξαιτίας κεραυνικών πληγμάτων, των οποίων το εύρος αυξάνει σε κάθε εξομοίωση.
Στη συνέχεια ελέγχεται η επικινδυνότητα των υπερτάσεων που εγείρονται για τα διάφορα μεγέθη κεραυνικού ρεύματος και εάν ο εξοπλισμός σε διαφορετικά σημεία του δικτύου αντέχει τις υπερτάσεις αυτές ή καταστρέφεται. Από τα αποτελέσματα προκύπτει ότι επικίνδυνες υπερτάσεις παρατηρούνται σε τμήματα της εναέριας γραμμής μεταφοράς πλησίον του σημείου κεραυνικού πλήγματος. Αντίθετα, το υπόγειο τμήμα του δικτύου αποδεικνύεται πιο ανθεκτικό, καθώς δεν εγείρονται επικίνδυνες υπερτάσεις ακόμα και για πολύ υψηλό κεραυνικό ρεύμα. / The purpose of this diploma thesis is the study of the behavior of overhead transmission lines and underground transmission cables against lightning. In favor of this purpose, a simulation of a hybrid transmission network takes place, which is composed of both overhead lines and underground cables, in order to examine transient overvoltages. These overvoltages are raised due to a lightning that strikes the shield wire of the terminal tower, where the interconnection of overhead line to underground cable takes place.
Chapter one presents the basic theory concerning atmospheric discharges. It describes the different types of lightning strikes, their parameters and basic characteristics. Furthermore, it analyzes the consequences of lightning and how to find the frequency that a lightning takes place in an area.
At the second chapter there is an introduction in the systems of electric energy and a presentation of the basic characteristics of overhead lines and underground cables. In addition, there is a comparison between those two means of electricity transmission.
Chapter three examines the types of errors and the causes of them at the electricity transmission lines. Moreover, it gives the basic parameters of the lightning current waveform.
Chapter four analyzes the insulation and protection of both overhead lines and underground cables against lightning. It also examines the mechanisms that raise overvoltages at the transmission lines. Afterwards, there are described two methods on how to define the place of shield wires at a transmission line.
Chapter five describes the ATP-EMTP simulation program, which is a specific software to simulate power systems. Its superiority for research like the present one is high lined and special emphasis is given to ATPDraw which is the main tool for the simulation.
At chapter six there is a detailed analysis of the hybrid network used in this simulation and of its basic components, which are the overhead lines and the underground cables. Furthermore, there is a presentation of the results of the simulation and the graphs of the overvoltages at different spots of the network, due to lightning strikes.
Afterwards, there is an evaluation of the risk of overvoltages that are raised for different lightning current sizes and if the equipment at different spots of the network sustains these overvoltages or it is destroyed. From the results, it is concluded that dangerous overvoltages are raised at sections of the overhead line near the lightning strike. On the contrary, the underground section of the network appears to be more resistant, as there are not raised dangerous overvoltages, even when the lightning current was too high.
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Pilot Tube Microtunneling: Profile of an Emerging IndustryJanuary 2011 (has links)
abstract: Trenchless technologies have emerged as a viable alternative to traditional open trench methods for installing underground pipelines and conduits. Pilot Tube Microtunneling, also referred to as the pilot tube system of microtunneling, guided auger boring, or guided boring method, is a recent addition to the family of trenchless installation methods. Pilot tube microtunneling originated in Japan and Europe, and was introduced to the United States in the year 1995 (Boschert 2007). Since then this methodology has seen increased utilization across North America particularity in municipal markets for the installation of gravity sewers. The primary reason contributing to the growth of pilot tube microtunneling is the technology's capability of installing pipes at high precision in terms of line and grade, in a wide range of ground conditions using relatively inexpensive equipment. The means and methods, applicability, capabilities and limitations of pilot tube microtunneling are well documented in published literature through many project specific case studies. However, there is little information on the macroscopic level regarding the technology and industry as a whole. With the increasing popularity of pilot tube microtunneling, there is an emerging need to address the above issues. This research effort surveyed 22 pilot tube microtunneling contractors across North America to determine the current industry state of practice with the technology. The survey examined various topics including contractor profile and experience; equipment, methods, and pipe materials utilized; and issues pertaining to project planning and construction risks associated with the pilot tube method. The findings of this research are based on a total of 450 projects completed with pilot tube microtunneling between 2006 and 2010. The respondents were diverse in terms of their experience with PTMT, ranging from two to 11 years. A majority of the respondents have traditionally provided services with other trenchless technologies. As revealed by the survey responses, PTMT projects grew by 110% between the years 2006 and 2010. It was found that almost 72% of the 450 PTMT projects completed between 2006 and 2010 by the respondents were for sanitary sewers. Installation in cobbles and boulders was rated as the highest risk by the contractors. / Dissertation/Thesis / M.S. Construction 2011
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Estudo do uso de cinemetria para a análise do deslocamento de maciço em obras subterrâneasDurán, César Augusto Arias January 2014 (has links)
As escavações subterrâneas têm estado sempre afetadas pelas condições dos maciços, os quais apresentam diferentes características e comportamentos frente a deformações ocasionadas após a escavação de uma galeria ou túnel. Em virtude disto, torna-se necessário uma análise dos parâmetros que permitam estabelecer as condições de segurança do túnel e propõe-se o uso de um sistema estéreo de rastreamento ótico para analisar o deslocamento de artefatos (conjunto de marcadores) instalados sobre o contorno das faces do túnel, a fim de detectarem-se deslocamentos do maciço em pontos estabelecidos com precisão menor a ±1 mm. O sistema proposto opera na região espectral do infravermelho, permitindo assim uma operação em ambientes com baixa luminosidade e com inserção de ruído ótico. Adicionalmente o trabalho inclui resultados de validação e desenvolvimento do sistema de visão estéreo baixo condições de dois cenários de diferente volume espacial, assim como o procedimento realizado para a calibração dos parâmetros intrínsecos e extrínsecos dos sensores do sistema (câmeras monocromáticas). Os resultados obtidos apresentam uma precisão de ±0,1881 mm para artefatos com três marcadores e uma precisão de ±0,4952 para artefatos com quatro marcadores. Finalmente, o sistema opera com uma sensibilidade de 0,99 mm na determinação da posição de um artefato associado a um ponto do perfil do túnel, e desta forma, podem-se definir as condições de estabilidade do maciço rochoso e os requisitos para auxilio as decisões de métodos de tratamento e aumento da segurança. / Underground excavations have always been affected by the conditions of mass, which have different characteristics and behaviors against deformation caused after excavation of a gallery or tunnel. Because of this, it is necessary an analysis of the parameters needed to establish the safety conditions of the tunnel and it is proposed the use of a stereo optical tracking to analyze the displacement of artifacts (set of markers) installed on the contour of tunnels’ faces in order to detect displacements of the mass points established with a precision lower than ±1 mm. This system operates in the infrared spectral region to take advantage of the low light and reduce the optical noise in environments with grace. Further work includes validation results and development of low stereo vision conditions of two different scenarios spatial volume, as well as the procedure carried out to calibrate the intrinsic and extrinsic parameters of the system sensors (monochrome camera) system. The results show an accuracy of ± 0,1881 mm for artifacts with three markers and an accuracy of ± 0,4952 for artifacts with four markers. Finally, the system operates with a sensitivity of 0,99 mm in the determination of an artifact associated with a point in the tunnel profile position, and thus, one can define the conditions for stability of the rock mass and assistance requirements for the decisions of treatment methods and increased.
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"They are a scum community who have organized:" The Georgia Straight, freedom of expression, and Tom Campbell’s war on the counterculture, 1967 – 1972Sherman, Jake Noah 15 January 2019 (has links)
The 1960s have a special place in the cultural memory of the West Coast of Canada. They have informed its regional identity, the cityscape of Vancouver, and the social infrastructure of the modern state. But lost in the mythos that has surrounded Vancouver’s long sixties is the story of the Georgia Straight. Founded by a group of poets in 1967 to combat a campaign launched by the municipal government to discriminate against the counterculture, it is today, in 2018, the most prosecuted newspaper in Canadian history. Between 1967 and 1972, the municipal and provincial government deliberately took advantage of the legal justice system to censor an outlet for dissent, with the end goal of inhibiting it from publishing. This thesis challenges popular conceptions of the 1960s in British Columbia’s popular memory by demonstrating the extent to which the state deliberately censored freedom of expression by attempting to silence an outlet for dissent, and highlights how the municipal and provincial government infringed on the civil liberties of Vancouver’s counterculture community, in one instance in August 1971, threatening it with outright violence. / Graduate
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Escenarios relacionados con la intrusión marina. Caso de estudio Cuenca Artemisa – Quivicán, Provincia Habana. La Habana – Cuba / Escenarios relacionados con la intrusión marina. Caso de estudio Cuenca Artemisa – Quivicán, Provincia Habana. La Habana – CubaNúñez Lafitte, Manuel 10 April 2018 (has links)
Sea water intrusion is the process by which the sea water in an aquifer displaces the sweet water as consequence of a sensitive reduction of the hydraulic head, either for natural actions or for anthropic activity Sea water intrusion takes place in the coastal aquifers mainly independently to the predominant lithology. In this work the scenario analysis is approached by studying the effects that sea water intrusion in dry years would produce to the supply of underground water to the City of Havana and Havana Province, when there would be high exploitation of the aquifers without maintenance of recharge works such as in South Dike.There would be a cartography of the scenario in danger to show the presage of the penetration expressed in the longitude of the marine intrusion wedge, taking as contour conditions the variable that may be unfavorable for their temporal variation, such as precipitation and depression. The thickness of the sheet of sweet water is considered constant. / La intrusión marina es el proceso por el cual el agua de mar desplaza en un acuífero el agua dulce como consecuencia de una reducción sensible de la carga hidráulica, ya sea por acciones naturales o por actividad antrópica.La intrusión marina tiene lugar principalmente en los acuíferos costeros independientemente a la litología predominante.En este trabajo se aborda el análisis del escenario que en el abasto de agua subterránea a la Ciudad de La Habana y Provincia Habana produciría la intrusión marina durante la ocurrencias de años secos, simultaneados, con altas explotaciones del acuífero y el no mantenimiento de obras de recarga como es el caso del Dique Sur.Se cartografía el escenario de peligro que muestra el pronóstico de la penetración expresada en longitud de la cuña de intrusión marina tomando como condiciones de contorno las variables que pueden ser desfavorables por su variación temporal, tales como la precipitación, explotación y abatimiento. Se considera constante el espesor de la lámina de agua dulce.
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Análise do trabalho em espaços confinados : o caso da manutenção de redes subterrâneasAraújo, Adriana Nunes January 2006 (has links)
Esta pesquisa trata de uma análise do trabalho de dez eletricistas que atuam em espaços confinados de redes subterrâneas de distribuição de energia, na Companhia Estadual de Energia Elétrica, Porto Alegre, RS. Foi identificada a demanda ergonômica dos eletricistas, com base em um método participativo (Análise Macroergonômica do Trabalho) de levantamento e avaliação dos dados, que gerou insumos para a melhoria das condições de trabalho e segurança e, conseqüente, promoção de prevenção de acidentes. A pesquisa revelou que os eletricistas consideram como aspectos mais positivos do trabalho os relacionamentos entre chefia, supervisores e colegas. Em contrapartida, apontam problemas críticos de diversas naturezas: biomecânico/posto, organização do trabalho, ambiental e relacionados à empresa. Também foram identificados níveis elevados de demandas físicas e mentais do trabalho, concluindo-se que o medo, evidenciado no discurso dos eletricistas, é referente ao trabalho com eletricidade e não ao trabalho em espaços confinados. Além disso, a pesquisa apontou cinco procedimentos, considerados como padrões mínimos, para a realização de trabalhos seguros em espaços confinados: reconhecimento, monitoramento da atmosfera, ventilação, treinamento e resgate.Apesar dos eletricistas não terem ciência da existência destes procedimentos, os mesmos foram citados, direta ou indiretamente nas entrevistas, como aspectos relevantes ao trabalho, sendo atribuído a maioria deles um baixo nível de satisfação. Com isso, conclui-se que a implantação de um programa de permissão de entrada em espaços confinados, além de promover a segurança neste ambientes tem relação direta com a satisfação dos trabalhadores. / The focus of this dissertation is the work analysis of ten electricians who act in confined space at underground power lines at the Estate Electricity Company in Porto Alegre, RS. It was identified the electricians’ ergonomic demand items. The research was carried out according to the participatory methods of survey and assessment of data, to improvement of safety and work conditions and, therefore, to prevent accidents. The research disclosed that the electricians have the relationship with their superiors, supervisors, and workmates as the most positive aspect of the job. On the other hand, they point out critical problems from different causes: biomechanical, task organization, environmental, and the ones related to the company. Overload regarding physical and mental work demand has been identified, proving that the fear, evident in the professionals’ speech is about the electricity, and not related to confined underground spaces. Besides, the research also displayed five procedures regarded as minimal standards to execute safe work in confined spaces: recognition, testing and monitoring atmosphere, ventilation, training and rescue. Despite the little knowledge electricians have on this criteria, some points of it were reported, some in an indirect way, during the interviews as relevant aspects to the work, being attributed to most of them a low level of satisfaction. Therefore, it comes to the conclusion that the implantation of a Permit-Requires Space Program, besides promoting accidents prevention in these spaces, has a direct relationship with the workers’ satisfaction.
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Podzemní voda v krajině Jihočeského regionu / Groundwater in the landscape of the South Bohemian regionŠTÁDLÍKOVÁ, Adéla January 2016 (has links)
The diploma thesis deals with groundwater issues. The village Jenín was chosen for the work. The work contains theoretical and practical part. Theoretical part explains the terms connected with groundwater and its sources. The parctical part describes the area of interest and there are listed the sources of groundwater that were found during the survey of the territory. Within the survey a short analysis of water was carried out for four groundwater sources. The conclusion of this work assesses the current status of groundwater resources and proposes measures. The work includes a list of sources that has been used, photohraphs of the area of interest and short water analysis.
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Análise de ponto ótimo de realocação da alimentação primária para mineração em câmaras e pilaresVincenzi, Ricardo Andre January 2015 (has links)
O método de lavra câmaras e pilares é muito utilizado em minas de carvão subterrâneo, principalmente nos estados de Santa Catarina e Paraná, onde todas as minas subterrâneas utilizam este método. Vale ressaltar, porém, que o método apresenta recuperações de lavra abaixo de 50%, dependendo do tamanho dos pilares, e a produtividade é altamente dependente de uma boa concatenação das operações unitárias. Entre os aspectos relacionados à eficiência produtiva, a distância de transporte é um item preponderante no desempenho do sistema. Devido à profundidade da lavra, há um aumento do tamanho dos pilares de sustentação da mina, e assim, surgem problemas relacionados ao incremento no tempo de ciclo de transporte dos equipamentos. O aumento da distância de transporte entre uma frente de lavra com material desmontado e o alimentador/britador primário, reduz o resultado da produção de um conjunto de equipamentos. Em mineração a céu aberto, este tipo de problema é resolvido com o aumento da frota de transporte, todavia, na mineração de carvão subterrânea, não é possível aumentar de forma irrestrita a quantia de máquinas em subsolo, pois impactaria diretamente na necessidade de incremento da vazão de ar, assim como, limitação de espaço para o tráfego de equipamentos. A aproximação da distância do ponto de descarga para um local adjacente às frentes de serviço é uma alternativa para solucionar a necessidade de incremento da frota de produção. No entanto, o ponto de mudança deve ser avaliado de forma consistente para determinar o momento mais adequado para que essa reaproximação proporcione um resultado ótimo. Este estudo buscou compreender esta etapa necessária ao processo produtivo, utilizando técnicas de regressão para analisar o impacto da distância de transporte na capacidade produtiva. O problema foi modelado e foram propostas alternativas que forneçam um sequenciamento de lavra capaz de amenizar os problemas decorrentes do aumento da distância de transporte das frentes de lavra aos respectivos pontos de descarga. Os resultados demonstraram que a distância de transporte tem influência direta na produção, mas não somente a distância máxima, mas também, uma distância mínima que deve ser respeitada para obter maior produtividade quando se tem a associação de equipamentos de produção. É possível concluir com este estudo que a distância de transporte tem impacto relevante e deve ser considerada, não tão somente no sequenciamento, mas também no dimensionamento da frota e consequente capacidade produtiva. / The room and pillar mining method is widely used in underground coal mines. Santa Catarina and Paraná where all underground mines use this method. Indeed, the method has mining recoveries below 50% and the productivity is highly dependent on a good concatenation of unit operations. Among the aspects related to production efficiency, the transport distance is an important item on system performance. Due to the depth of the mine, there is an increment in the size of the underground supporting pillars, and consequently, problems related to the increase in equipment cycle times. The increase of the transportation distance between mining faces and the primary crusher reduces the result of a set of production equipment. In open pit mining, this problem is solved by increasing the haulage fleet, however, in the underground coal mining, the number of machines cannot be increased indefinitely because it would impact directly on the need of increased air flow. Therefore, the approximation of the distance from the discharge point to an adjacent location from the mining faces is an alternative to address the need of increased production fleet. However, the relocation point must be evaluated consistently to determine the most appropriate time to get the most from this approach. The goal of the study was to understand this imperative step for the production process, using regression techniques to analyze the impact of transport distance in productive capacity. Based on the experimental design used in this study, alternative proposals provide a mining sequence able to mitigate the problems from increasing transportation distance from mining faces to their discharge points. The results show that the transport distance has directly influence on the production, and it is not limited to the maximum distance. Likewise, a minimum distance must be respected for higher productivity when you have the combination of production equipment. So, it is possible to conclude that the transport distance has a significant impact and must be considered not only during the sequencing, but also when determining the fleet size and consequent production capacity.
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