Logical designing of yield pillar base on coal pillars yielding process
Subject Areas :Kazem Oraee 1 , Navid Hosseini 2
1 - استاد دانشگاه استرلینگ انگلستان
2 - دانشجوی دکترای مهندسی معدن دانشگاه آزاد اسلامی واحد علوم و تحقیقات
Keywords: Design, Numerical model, Longwall, Pillar, Strain-Softening, Yielding,
Abstract :
The longwall mining method is one of the best methods for exploitation of underground horizontalto near horizontal coal layers. The high production and safety are the typical advantages. Entriesof both sides longwall panel having important role in product and safety. With increasing depth ofmine, difficulty of supporting condition of entries increases. One of the basic solutions for suchentries stability, particularly at deep mines, is to use yield chain pillars. Since, the behavior of coalpillar at post-peak regime is not known, so the logical designing of these yield chain pillars are notwell established.In this paper, two strain-softening models with numerical and analytical fundamentals areanalyzed. These models are studied for a row of yield chain pillar at longwall mining system at700 m dept of surface ground. In this study, only development phase of longwall mining system iscontemplated while the deformation, yielding and failure possibility are considered beforelongwall operation runs. Results show in deep longwall mine yield chain pillar can be used. Inaddition, both analyzed strain-softening models, having required potential for rather optimumunderstanding of pillar yielding behavior. Therefore, could be a base for yield pillar logical design.Study development shows this approached yield pillar design is sensitive to pillar behavior aftercoal peak strength. In addition, due to two-dimensional modeling, front abutment load influencecould not be evaluated
