Results of modelling with equivalent materials and results of mathematical modelling here by means of the finite elements method are presented. The conditions of dynamic loading of various types of supports of the individual entries, incl. the combined support consisting of steel arches and roof bolts were simulated.
Les resultats des essais sur modeles reduits des materiaux equivalents sont presentes avec les resultats des essais modèles mathematiques par r intermediaire de la methode des elements finis. On a modele les conditions des charges dynamiques des types differents du soutènement des voies consistant des arcs en acier et des boulons c'ancrage. Les notices theoriques et pratiques montrent que l'ancrage des voies de mine peut assurer la protection effective des voies en question contre la charge dynamique gui est en etroite relation avec la genese des coups de roche et des degagements instantanes. Les resultats presentes nous apportent des connaissances nouvelles dans le domaine des essais mathematiques et physiques sur les modèles reduits de l'effectivite du boulonnage du toit sous l'influence de la charge dynamique.
Die Ergebnisse des Modellverfahrens durch aquivalente Stoffe werden in dieser Arbeit zusammen mit den Ergebnissen des mathematischen Modellverfahrens mit Hilfe der Methodevon Endelementen prasentiert. Es wurden die Bedingungen von dynamischen Belastungen verschiedener Typen des Streckengrubenausbaues zusanmen mit dem kombinierten Grubenausbau bestehend aus den Stahlbögen und Bolzen simuliert. Theoretische und auch praktische Erfahrungen weisen auf, daβ der Ankerausbau sehr effektivvoll die Grubenausbauten gegen die dynamische Belastung schuetzen kann, die mit der Entstehung der Gebirgsschlage und AusbrLuche verbunden ist. Diese vorgelegte Arbeit bringt einige Erfahrungen und Erkenntnisse aus dem Bereich des physikalischen und mathematischen Modellverfahrens der Wirkung des Ankerausbaus bei der dynamischen Beanspruchung.
In accordance with mining under the conditions of rock bursts danger, the problem of protection of the entry No. 13909 of the "CSA"-coal Mine situated in Karvina, the Czech Republic, was studied. The dynamic phenomena were assumed to be occurred in this entry. A group of specialists made a draft of five variants for the protection of this entry; use of roof bolting was proposed in four cases besides usually used steel supports. In same cases, roof bolting with a steel support; in sane cases, roof bolting in a combination with supporting parts and compensating areas were proposed. The steel support only was situated on the "CSA D5"-model, which served as a comparative model for the evaluation of the efficiency of auxiliary supporting parts. Figures 1–6 show the scheme of proposed support. It is obvious that the "CSA D5"- -model is a comparative model; the "CSA D3"-model with roof bolting is the auxiliary model of the steel-arch support; on the "CSA D1"-model, the combination of supporting parts and destressing boreholes was checked; the "CSA D2"-model is the model with supporting parts and a compensating area; and the "CSA D4" and "CSA D6"- -models are the models with supporting parts, roof bolts and a compensating area.
Basic parameters of this model research are based on well-developed methodology:- -Rock mass and entries are simulated in a linear scale of 1:50 according to usual conditions of the Ostrava-Karvina Coalfield. - Steel support including facing is simulated by means of exposy-varnish layer. - Simulation of another measurements, i.e. props and roof bolts corresponds with physical similarity laws. - Dynamic shock is caused by a fall of a load of weight of 62 kg from the height of 2 meters, what causes energy of 10 9 J. - Simulated roof bolts have their anchoring strength of 70 up to 130 kN. - Clamping force is 80 kN.
