Analytical model for the mechanical behaviour of bolted rock joints subjected to shearing

Pellet, Frédéric; Egger, P.

doi:10.1007/bf01079755

Cited by 135 publications

(39 citation statements)

References 2 publications

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“…Ferrero [14] proposed a shear strength model for a reinforced joint that considered both the dowel effect and the incremental increase in axial force due to the bar deformation. Pellet and Egger [15] related theoretical and experimental analyses of the rock bolt shear strength and found that bolts installed perpendicular to a joint plane allowed the greatest displacement along a joint prior to failure but that the displacement at failure decreased rapidly as the angle between the bolt and joint plane decreased. They also found that harder rock led to bolt failures at smaller displacements.…”

Section: Introductionmentioning

confidence: 99%

Macro-Micro Failure Mechanisms and Damage Modeling of a Bolted Rock Joint

Wang

Zhang

Jiang

et al. 2017

Advances in Materials Science and Engineering

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The anchoring mechanism of a bolted joint subjected to a shear load was investigated using a bilinear constitutive model via the inner-embedded FISH language of particle flow code based on the discrete element method. The influences of the anchoring system on the macro-/micromechanical response were studied by varying the inclination angle of the bolt. The results indicate a clear relationship between the mechanical response of a bolted rock joint and the mechanical properties of the anchoring angle. By optimizing the anchorage angle, the peak strength can be increased by nearly 50% relative to that at an anchorage angle of 90 ∘ . The optimal anchorage angle ranges from 45 ∘ to 75 ∘ . The damage mechanism at the optimal anchorage angle joint is revealed from a macroscopic mechanical perspective. The concentration of the contact force between disks will appear in the joint and around the bolt, resulting in crack initiation. These cracks are mainly tensile cracks, which are consistent with the formation mechanism for compression-induced tensile cracks. Therefore, the macroscopic peak shear stress in the joint and the microscopic damage to the anchoring system should be considered when determining the optimal anchoring angle to reinforce a jointed rock mass.

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Section: Introductionmentioning

confidence: 99%

Macro-Micro Failure Mechanisms and Damage Modeling of a Bolted Rock Joint

Wang

Zhang

Jiang

et al. 2017

Advances in Materials Science and Engineering

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“…The calculation of the shear resistance (expressed as spring stiffness K rb,shear,i ) is performed according to the relationships published by Pellet & Egger [18]. The axial resistance of the rock bolts is calculated from their elongation, calculated as displacement difference between the innermost point of the rock bolt (excavation boundary) and the outermost point, and the rock bolt cross section and material properties.…”

Section: Gleichgewichtsfindungmentioning

confidence: 99%

Novel method for ductile lining pre‐design / Neues Verfahren zur Vorbemessung eines duktilen Ausbaus

Radončić

Schubert

2011

Geomechanics and Tunnelling

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The design of a ductile lining has to incorporate a number of influences. Both the influences of the ground conditions and the construction have to be considered in order to develop a safe and economical solution. Special focus has to be set on a plausible prediction of the time-and excavation-dependent displacement development and its interaction with the transient shotcrete properties, load-displacement behaviour of the yielding elements and the entire excavation sequence. The rather underdeveloped state of the state-of-the-art methods for ductile support pre-design is somewhat contrasting the frequent practical usage of this support concept. Especially the development of semi-empirical or analytical methods, allowing a quick initial assessment of the system behaviour and incorporating the influences mentioned above, has been neglected in favour of the numerical analysis methods.A novel calculation method, analogous to the convergence confinement method, applicable to non-circular excavation geometries and unsymmetrical displacement fields is presented in the course of this paper. Castigliano's second law and the associated balance of the outer work enable determining the equilibrium point between the ground and the installed support measures and the determination of the support capacity. Additional semi-empirical relationships, derived from a series of systematic 3D numerical simulations, allow prediction of the pre-relaxation and of the longitudinal displacement profiles for a top heading advance. The combination of these relationships with the proposed energy-based equilibrium criterion allows the establishment of a coherent calculation method, addressing and incorporating all relevant geomechanical and constructional influences. A practical application example and the verification of the method are shown and discussed, with the calculation results compared to the measurement data from the exploratory tunnel Paierdorf (Lavanttal fault system).The same ideas regarding the balance of outer work between the support measures and the rock mass can be used for finding clear boundaries of ground conditions where a flexible support becomes imperative.

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“…Several studies have been conducted in the past to find out the parameters, which influence the strength of the reinforced rocks. Studies conducted by Dight (1982), Egger and Zabuski (1991), Pellet and Egger (1996), McHugh and Signer (1999), and Sakurai (2010) have indicated that the strength of reinforced jointed rock depends upon the strength of parent intact rock. Further, the orientation of the joints with respect to the bolt direction has also been found to influence the strength of reinforced rock (Bjurstrom, 1974;Haas, 1976Haas, , 1981Ludvig, 1983;Pellet and Egger, 1996;Grasselli et al, 1999;and Grasselli, 2005).…”

Section: Introductionmentioning

confidence: 96%

“…Studies conducted by Dight (1982), Egger and Zabuski (1991), Pellet and Egger (1996), McHugh and Signer (1999), and Sakurai (2010) have indicated that the strength of reinforced jointed rock depends upon the strength of parent intact rock. Further, the orientation of the joints with respect to the bolt direction has also been found to influence the strength of reinforced rock (Bjurstrom, 1974;Haas, 1976Haas, , 1981Ludvig, 1983;Pellet and Egger, 1996;Grasselli et al, 1999;and Grasselli, 2005). In addition, the mechanical properties of the bolt (Ferrero, 1995;Ferrero et al, 1997) and the grout (Villaescusa et al, 2008) also contribute to the strength of reinforced rock.…”

Section: Introductionmentioning

confidence: 96%