scholarly journals Relationship of the discontinuities and the rock blasting results

Author(s):  
S. Yahyaoui ◽  
A. Hafsaoui ◽  
A. Aissi ◽  
A. Benselhoub

The Geological discontinuities such as joint are the most common discontinuities present in the rock mass. A model scale study was carried out to evaluate the effect of the joints on rock blasting. Single hole tests at three selected burdens (optimum, less than optimum and more than optimum) were done on six different joint orientations. The joint orientation angles were 0°, 30°, 60°, 90°, 120° and 150° rotating in anticlockwise direction from the floor of the bench in a plane perpendicular to the free face. Bench models of dimensions 515x335x215 mm with a bench height of 50 mm were prepared by binding sandstone slabs of 25 mm thickness with an adhesive. The models were blasted by n°6 electric detonators. The dynamic and static properties of sandstone are given. The bench crater formed and the fragmentation produced were predominantly influenced by the position of charge with respect to the joint orientation. Severe toes were noticed in models with vertical joints and with joints dipping away from the face. Over breaks were observed in horizontally bedded models and in models with joints dipping towards the free face. Over breaks were observed in horizontally bedded models and in models with joints dipping towards the free face. The size of the broken fragments at 20 mm burden was found to be finer than the fragments obtained at 30 mm and 40 mm burdens for all joint orientations except vertical.

2012 ◽  
Vol 204-208 ◽  
pp. 1331-1334
Author(s):  
Hong Yan Zhang ◽  
Qing Yang Yu ◽  
Neng Juan Zhou

It is a kind of effective way to study blasting to joint rock mass using the finite element method, in which the key is algorithm and model building. Comparing the relationship of explosive and blasting structure simulated by adopting Lagrange method and ALE method, the paper considers that Lagrange method is more close to practice, and could finish numerical simulation analysis of the intact rock blasting.


2014 ◽  
Vol 553 ◽  
pp. 445-451
Author(s):  
Zeinab Aliabadian ◽  
Mansour Sharafisafa

Rock masses consist of intact rock and discontinuities such as faults, joints and bedding planes. The presence of such discontinuities in rock masses dominates the response of jointed rock masses to static and dynamic loading. These structural weak planes seriously hinder and affect the propagation of stress waves in rock mass. The joints parameters such as persistence, orientation, distribution patterns, spacing and filling material have a significant effect on the response of rock masses against wave propagation. In most studies of blast induced wave propagation in jointed rock mass, it is assumed that joints are continuous. In many situations the rock mass consists of non-continuous joints and rock bridges. Rock bridges and discontinuous joints have a different effect on wave and fracture propagation in a blasting operation. With regard to complexities associated with rock blasting in particular in jointed media, numerical tools are viable alternatives for rock blasting analysis. In this study the DEM methods was employed to investigate the effects of rock bridges on the wave propagation process. A plain strain 2D scenario was assumed and a single blasthole explosion was simulated. Three models with different jointing orientation patterns including jointing pattern parallel to free face, perpendicular to free face and orientated at 45 degree with respect to free face were analyzed numerically to investigate rock mass fracturing while blast wave propagation. The discontinuous joints were considered to be filled with weak materials (open joints) and rock bridges are composed of intact rock. In order to allow material plastic failure, a Mohr-Coulomb material model was used. The analysis results show that the stress concentration at the rock bridge location leads to excessive fracturing. This effect is more visible at the free face where the stress wave reflection occurs. Moreover, the obtained results show that the pattern and orientation of non-continuous joint system has a pronounced effect on rock fragmentation.


Energies ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 562
Author(s):  
Marek Jendryś ◽  
Andrzej Hadam ◽  
Mateusz Ćwiękała

The following article analyzes the effectiveness of directional hydraulic fracturing (DHF) as a method of rock burst prevention, used in black coal mining with a longwall system. In order to define changes in seismic activity due to DHF at the “Rydułtowy” Black Coal Mine (Upper Silesia, Poland), observations were made regarding the seismic activity of the rock mass during coal mining with a longwall system using roof layers collapse. The seismic activity was recorded in the area of the longwall itself, where, on a part of the runway, the rock mass was expanded before the face of the wall by interrupting the continuity of the rock layers using DHF. The following article presents measurements in the form of the number and the shock energy in the area of the observed longwall, which took place before and after the use of DHF. The second part of the article unveils the results of numerical modeling using the discrete element method, allowing to track the formation of goafs for the variant that does not take DHF into consideration, as well as with modeled fractures tracing DHF carried out in accordance with the technology used at “Rydułtowy” coal mine.


2020 ◽  
Vol 36 (03) ◽  
pp. 309-316
Author(s):  
Ozcan Cakmak ◽  
Ismet Emrah Emre

AbstractPreservation of the facial nerve is crucial in any type of facial procedure. This is even more important when performing plastic surgery on the face. An intricate knowledge of the course of the facial nerve is a requisite prior to performing facelifts, regardless of the technique used. The complex relationship of the ligaments and the facial nerve may put the nerve at an increased risk of damage, especially if its anatomy is not fully understood. There are several danger zones during dissection where the nerve is more likely to be injured. These include the areas where the nerve branches become more superficial in the dissection plane, and where they traverse between the retaining ligaments of the face. Addressing these ligaments is crucial, as they prevent the transmission of traction during facelifts. Without sufficient release, a satisfying pull on the soft tissues may be limited. Traditional superficial musculoaponeurotic system techniques such as plication or imbrication do not include surgical release of these attachments. Extended facelift techniques include additional dissection to release the retaining ligaments to obtain a more balanced and healthier look. However, these techniques are often the subject of much debate due to the extended dissection that carries a higher risk of nerve complications. In this article we aim to present the relationship of both the nerve and ligaments with an emphasis on the exact location of these structures, both in regard to one another and to their locations within the facial soft tissues, to perform extended techniques safely.


2011 ◽  
Vol 90-93 ◽  
pp. 2033-2036 ◽  
Author(s):  
Jin Shan Sun ◽  
Hong Jun Guo ◽  
Wen Bo Lu ◽  
Qing Hui Jiang

The factors affecting the TBM tunnel behavior in jointed rock mass is investigated. In the numerical models the concrete segment lining of TBM tunnel is concerned, which is simulated as a tube neglecting the segment joint. And the TBM tunnel construction process is simulate considering the excavation and installing of the segment linings. Some cases are analyzed with different joint orientation, joint spacing, joint strength and tunnel depth. The results show that the shape and areas of loosing zones of the tunnel are influenced by the parameters of joint sets and in-situ stress significantly, such as dip angle, spacing, strength, and the in-situ stress statement. And the stress and deformation of the tunnel lining are influenced by the parameters of joint sets and in-situ stress, too.


2000 ◽  
Vol 12 (1-4) ◽  
pp. 141-161
Author(s):  
Robert N. Mccauley

AbstractThe aims of this paper are to identify three barriers to the development of cognitive approaches to the study of religion and to suggest how each might be circumvented. The first of these barriers is methodological and lurks amid two issues that, historically, have dominated anthropologists' reflections on the relationship of their discipline to psychology. The older of the two can be characterized as the "psychic unity" controversy (see Shore 1995). The second issue is the controversy over the "autonomy of culture". Advocates of the latter thesis are usually unsympathetic to psychological explanations of religious phenomena. In the first section, I shall begin by briefly examining each of those issues and then exploring the connections between the two as well as interesting logical tensions that arise in the face of popular responses to each. In section two, I shall consider a pair of barriers to a cognitive psychology of religion rooted in two strategies that have dominated many psychologists' approaches to the study of religion. I will argue that for some purposes, at least, both strategies should be relaxed. Finally, in section three, I shall briefly sketch one sort of cognitive approach to religious phenomena, suggesting how it handles the two strategic barriers in particular.


2017 ◽  
Vol 3 (1) ◽  
Author(s):  
Larissa Fonseca

Sinopse: Em meio ao colorido de goiabas, batatas e flores mais que cheiros e sabores, descobrir pessoas. Agricultoras e agricultores que com suas histórias e lutas, estão representados nas varandas e nas mesas da cidade. Trazer a imagem não de uma feira, mas de cada pessoa que diariamente se dedica ao cultivo e à produção de alimentos. Encontrar o rosto e as escolhas de outros modos de fazer agricultura, de outros modos de se alimentar. De assentados e suas lutas pela preservação de sementes crioulas, de jovens universitários e sua determinação em permanecer no campo e de fumicultores aposentados dispostos a limpar suas terras dos venenos de mais 30 anos de cultivos agressivos, é feita a Feira Sabores da Terra. Feira da agricultura familiar do município de Canguçu, Rio Grande do Sul, que acontece todas as segundas-feiras à tarde e reúne cerca de 18 produtores. Em um pavilhão de madeira no centro da cidade são expostos doces coloniais, panificados, frangos congelados, farinhas, feijões, legumes, verduras, frutas e flores, em variedade conforme a estação do ano. Produtos que são vendidos entre boas conversas, rodas de chimarrão e é claro, uma melancia bem gelada ou uma deliciosa rapadura. Para a permanência e continuação da feira, que se realiza há pouco mais de um ano, os feirantes têm enfrentado e superado dificuldades. A distância de suas propriedades até a cidade, muitas das vezes são mais do que duas horas de viagem. A demanda, pelos consumidores, por produtos conforme padrões estéticos dos alimentos produzidos com veneno. O cansaço de mãos que, com mais de 40 anos de trabalho, ainda enfrentam a roça durante toda a semana e o frio, a chuva e o calor de uma feira praticamente ao ar livre. O conciliar o trabalho agrícola e a feira com os estudos, cujo acesso limitado pela distância das universidades, das oportunidades de estágios e pela dificuldade de ascender ao ensino público superior. Apesar de tão próximos, rostos e mãos muitas vezes invisíveis em escolhas alimentares. Gente que oportuniza uma alternativa à alimentação. Alimentação proveniente da relação de mulheres e homens com a terra, de suas sabedorias e ações. Feira Sabores da Terra, um ponto de aproximação entre o campo e a cidade, entre o cultivo e o alimento, entre o cuidado e o sabor. De agricultoras e agricultores e seus feijões, morangos e biscoitos. Este ensaio fotográfico é parte da agenda de pesquisa “Saberes e Sabores da Colônia”, desenvolvida no âmbito do Grupo de Estudos e Pesquisas em Alimentação e Cultura (GEPAC) e vinculada ao Bacharelado e ao Programa de Pós-Graduação em Antropologia da Universidade Federal de Pelotas. Synopsis: In the middle of colored places with guava , potatoes and flowers more than smells of flavors, we discover people. Farmers, with your stories and struggles, are represented on the balconies and tables of the city. Representing the image of each person that daily is dedicated to the cultivation and food production, not just the image of a fair is much more than that. Find the face and choices of other ways of doing agriculture and others ways of feeding. From the land reform settlements and their struggles for the preservation of native seeds, of university students and their determination to remain in the field and retires tobacco growers willing to clear their land of the poisons of another 30 years of aggressive crops, is made the Flavors of the Earth Fair. Family Agriculture Fair, in the Canguçu City in Rio Grande do Sul, Brazil, of what happens on every Monday afternoon and brings together about 18 small farmers. In a wooden pavilion in Downtown city are exposed colonial sweets, bakery products, quick-frozen, flours, beans, vegetables, fruits and flowers in variety according to season. Products that are sold as God´s taste is of course chimarrão, and watermelon ice-cold or a delicious rapadura. For the permanence and continuation of the green fair, been held little more than a year ago, the small farmers have had and overcome difficulties. The distance of their properties of the Downtown , often last more than two hours of the trip. The consumer demand by products according to aesthetic standards of foods produced with venom. The fatigue of hands, still for more than 40 years of work, are still facing small farm during the days in a cool, rain and heat weather and the a fair still open. To reconcile agricultural work and the fair with studies, to which access is restricted by distances from universities, internship opportunities, and the difficulty of access to higher public education. Although close, often invisible faces and hands in food choices. People who offer alternative food. Food derived from the relationship of men and women to the land, of his wisdom and actions. Flavors of The Hearth Fair, a point of approximation between the countryside and the city, between the crop and the food, between care and taste. Of farmers and agriculturists and their beans, strawberries and biscuits. This photo essay is part of research agenda “Knowledge and tastes of the agricultural colony”, developed in the framework of the Group of the Studies and Researches in Food an Culture (GEPAC) and linked to the Bachelor’s and the Postgraduate Program In Anthropology of Federal University of Pelotas. Palavras-chave: Agricultura Familiar – Campesinato – Feira – Alimentação - Consumo Key-words: : Family Agriculture - Peasantry – Fair – Food - Consumption Ficha técnica: Direção: Larissa Fonseca Roteiro: Larissa Fonseca Fotografia: Larissa Fonseca Coordenação de Pesquisa: Renata Menasche Edição de Imagem: Larissa Fonseca e Hamilton Bittencourt Assessoria em Imagem: Claudia Turra Magni Credits: Author: Larissa Fonseca Photographs: Larissa Fonseca Direction: Larissa Fonseca Research Coordination: Renata Menasche Image Editing: Larissa Fonseca e Hamilton Bittencourt Image Consulting: Claudia Turra Magni.


2012 ◽  
Vol 130 ◽  
pp. 42
Author(s):  
Mohammed Alghoul ◽  
Ozan Bitik ◽  
Jennifer McBride ◽  
James E. Zins

2017 ◽  
Vol 5 (1) ◽  
pp. 25
Author(s):  
Ahmad Jauhari ◽  
Asmaran AS ◽  
Siti Faridah

Al Jihad  Mosque Banjarmasin is a mosque that is identical with Muhammadiyah, this mosque is followed by many pilgrims and loyal at the time of the implementation of prayers fardu congregation. Jamaah consists of various groups regardless of background, both in terms of age, economy, organization and even the sick pilgrims (post-stroke) are actively involved in congregation. Active Jamaat prayers in congregation do not only come from residents around the mosque complex, but also many pilgrims who come from outside the mosque complex, even the distance difference between their residence with the mosque a few kilometers. In heavy rainy weather conditions, they still enthusiastically follow the prayers in congregation fardu mosque. In addition, there are things that are felt by pilgrims such as comfort, tranquility of heart and mind, emotional stability, silaturrahim which all is related to emotional intelligence.In this study, the main problem is how is the relationship of prayer in congregation with emotional intelligence in the congregation of Al Jihad Mosque Banjarmasin ?. The method used is quantitative and qualitative descriptive method with methodological arrangement such as approach and type of research, research location, population and sample, data and data source, procedure and data collection, quantitative and qualitative technical data analysis.The result of the study found that there is a correlation between salat fardu congregation with emotional intelligence, this is proved by the data from questionnaires from 30 pilgrims (respondents) that is: able to control the impulse of worldly lusts with the highest opinion is 60% said yes and 40% stated sometimes .Motivating yourself with the highest opinion is 90% states yes and 10% states sometimes. Able to survive in the face of trials with the highest opinion is 86.67 states yes and 13, 33 states sometimes. No exaggeration with the highest opinion is 90% states yes and 10% states sometimes. Being able to set the mood with the highest opinion is 86.33% and 13.33 states sometimes. Keeping the stress burden does not cripple the thinking ability with the highest opinion is 90% states yes and 10% states sometimes. The ability to empathize and pray with the highest opinion is 90% say yes and 10% say sometimes.


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