scholarly journals Numerical Simulation of Fully Grouted Rock Bolts

10.5772/48287 ◽  
2012 ◽  
Author(s):  
Hossein Jalalifar ◽  
Naj Aziz
Keyword(s):  
Numerical Simulation ◽  
Rock Bolts ◽  
Grouted Rock Bolts

Guided Wave Nondestructive Inspection of Grouted Rock Bolts: Experiment and Numerical Simulation

2011 ◽  
Vol 361-363 ◽  
pp. 108-115
Author(s):  
Wen He ◽  
Kui Zhao ◽  
Wang Cheng ◽  
Yi Li ◽  
Chang Suo Zhang ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Guided Wave ◽  
Empirical Formulas ◽  
Rock Bolts ◽  
Reflected Waves ◽  
Impact Echo ◽  
Excited Wave ◽  
Numerical Simulation Methods ◽  
The Impact ◽  
Grouted Rock Bolts

The properties of a longitudinal guided wave with central frequency 5kHz propagating in partially grouted rock bolts were studied by experimental and numerical simulation methods. The guided wave was excited by the impact–echo method on the free end of the bolt, and the excited wave measured in the experiments was used as excitation input in the numerical simulation. The numerical results match well with the experimental ones. Two empirical formulas were obtained for when the reflected waves from the upper interface and from the embedded end of the bolt could be distinguishably detected. Conclusion is drawn from the simulation results that the guided wave energy velocity in the embedded section of the bolt increases with the increase of elastic modulus of the grout media. A new method was proposed for anchorage quality testing and its effectiveness was proved by a testing example.

scholarly journals An Improved Numerical Simulation Approach for the Failure of Rock Bolts Subjected to Tensile Load in Deep Roadway

Geofluids ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-21
Author(s):  
Rui Wang ◽  
Jian-biao Bai ◽  
Shuai Yan ◽  
Yuan-ba Song ◽  
Guang-dong Wang
Keyword(s):  
Numerical Simulation ◽  
Tensile Load ◽  
Elongation Rate ◽  
Original Model ◽  
Rock Bolt ◽  
Tensile Failure ◽  
Simulation Approach ◽  
Rock Bolts ◽  
Modified Model ◽  
Free Section

Our goal was to develop an effective research tool for roadways with significant deformations supported by rock bolts. The improved numerical simulation approach is constructed through additional development of FLAC3D. The aim is to modify the shortcoming that the original model in FLAC3D regards the plastic tensile strain of any arbitrary rock bolt element node as the rupture discrimination criterion. The FISH programming language is adopted to conduct the secondary development and to embed the revised model into the main program of FLAC3D. Taking an actual mining roadway as the simulation object, two simulation schemes adopting the newly improved approach and the original method were conducted, respectively. The results show that (1) the PILE element that constitutes the rock bolt-free section with the maximum elongation rate ruptures after modification, while the rock bolt tendon elongation rate reaches beyond the predefined tensile rupture elongation rate; (2) the modified model in which the rock bolt is mainly subjected to tension realises the tensile rupture phenomenon at the end of the rock bolt-free section and the rock bolt at the junction between the free section and the anchoring section; and (3) only four rock bolts that are in the roadway sides showed rupture in the modified model, and all rock bolts showed rupture in the original model. The tensile failure of the rock bolt led that the modified model scheme is closer to the actual. Compared with the modified model, in the original model, deformation of the surrounding rock masses is severe. This is resulted by the rupture of all rock bolts in the original model. The analysis shows that the improved numerical simulation approach is much more reliable for large deformation roadway behavior with rock bolt support.

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