Strain Measurement Method of Fully-Grouted Rock Bolt in Rock Mass Fractured Zone

doi:10.12068/j.issn.1005-3026.2021.01.020

Abstract

Abstract: Due to the effects of discontinuous deformation in fractured rock masses and complex shearing between the rock bolt and the grout， the strain of rock bolt in fractured zone can hardly be measured accurately. A fully-grouted rock bolt was prepared by using 3D printing， and strain gauges were installed inside and outside the bolt respectively. The evolution law of tensile strain in the fully-grouted rock bolt during the fracture propagation process was obtained by uniaxial compression test. It was found that the outer strain gauges were greatly affected by the shear deformation of the grout， and the measurement results are easy to be distorted when the plastic deformation capacity of the grout is high. However， the internal strain gauges could accurately obtain the complete strain of bolt. Finally， the failure process of rock bolt in fractured zone was numerically simulated by FLAC software， the influence of strain gauge location on the measurement results was verified， which further proved the reliability of measurement by strain gauges inside the rock bolt.

Key words: rock mass; fracture; rock bolt; strain; measurement method

CLC Number:

TU45

HAN Tao， JIN Chang-yu， LU Yu， LIU Dong. Strain Measurement Method of Fully-Grouted Rock Bolt in Rock Mass Fractured Zone[J]. Journal of Northeastern University(Natural Science), 2021, 42(1): 131-138.

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