Eine Plattform für die Wissenschaft: Bauingenieurwesen, Architektur und Urbanistik
Eine Plattform für die Wissenschaft: Bauingenieurwesen, Architektur und Urbanistik
3D Behaviour of bolted rock joints: experimental and numerical study
Excavation size is a key parameter in the stability of underground openings in rock, and the larger the excavation, the less stable the roof tends to be. In very poor rock masses, large excavations have an unsupported stand-up time less than the minimum time required to support the roof after the excavation. Therefore, the principal objective in the design of a support system is to help the rock mass to support itself. During recent decades the use of rock bolts, which actually form a part of the rock mass, has become more and more widespread. Indeed, the use of rock bolts is a very flexible method that can be combined with wire mesh, shotcrete and concrete lining to cope with almost any situation encountered during mining or tunnelling. Various types of bolts are used today, and an understanding of the way in which these bolts work is essential for an optimal, safe, and economical use. Fully grouted, untensioned bolts have been commonly used in rock mechanics (i.e., mines, rock fall stabilisation, underground works) for many years. In the 1980s a new type of bolt, called Swellex, was developed, becoming more and more widespread because of their easy and fast installation. However, regardless of the type, the mechanical behaviour of the bolted rock joint is not fully understood, and only the experience accumulated on rock bolting gives the know-how for the reinforcement calculation and execution. In the paper the different mechanical responses of full steel bars as opposed to the frictional Swellex are discussed. The study was done through experimental tests coupled with numerical simulations. The analysis of the results obtained both from finite element (FEM) modelling, and from largescale (1 : 1) shear tests on rock joints, reinforced with fully grouted rods and Swellex bolts, clearly shows that the two bolt types deform in dissimilar ways, responding very differently to shear load.
3D Behaviour of bolted rock joints: experimental and numerical study
Excavation size is a key parameter in the stability of underground openings in rock, and the larger the excavation, the less stable the roof tends to be. In very poor rock masses, large excavations have an unsupported stand-up time less than the minimum time required to support the roof after the excavation. Therefore, the principal objective in the design of a support system is to help the rock mass to support itself. During recent decades the use of rock bolts, which actually form a part of the rock mass, has become more and more widespread. Indeed, the use of rock bolts is a very flexible method that can be combined with wire mesh, shotcrete and concrete lining to cope with almost any situation encountered during mining or tunnelling. Various types of bolts are used today, and an understanding of the way in which these bolts work is essential for an optimal, safe, and economical use. Fully grouted, untensioned bolts have been commonly used in rock mechanics (i.e., mines, rock fall stabilisation, underground works) for many years. In the 1980s a new type of bolt, called Swellex, was developed, becoming more and more widespread because of their easy and fast installation. However, regardless of the type, the mechanical behaviour of the bolted rock joint is not fully understood, and only the experience accumulated on rock bolting gives the know-how for the reinforcement calculation and execution. In the paper the different mechanical responses of full steel bars as opposed to the frictional Swellex are discussed. The study was done through experimental tests coupled with numerical simulations. The analysis of the results obtained both from finite element (FEM) modelling, and from largescale (1 : 1) shear tests on rock joints, reinforced with fully grouted rods and Swellex bolts, clearly shows that the two bolt types deform in dissimilar ways, responding very differently to shear load.
3D Behaviour of bolted rock joints: experimental and numerical study
3D-Verhalten geankerter Gesteinsklüfte: eine experimentelle und numerische Studie
Grasselli, G. (Autor:in)
2005
12 Seiten, 17 Bilder, 6 Tabellen, 32 Quellen
Aufsatz (Zeitschrift)
Englisch
3D behaviour of bolted rock joints: Experimental and numerical study
| British Library Conference Proceedings | 1998
Behaviour of bolted composite joints experimental study
| British Library Conference Proceedings | 2002
Behaviour of bolted composite joints: experimental study
| Online Contents | 2004
Behaviour of bolted composite joints: experimental study
| Elsevier | 2003
Behaviour of bolted cast iron joints
| Elsevier | 2017