A New Rock Mass Classification Method at Tunnel Face for Tunnel Support System

Akagi, Wataru; Sano, Aya; Shinji, Masato; Nishi, Takuro; Nakagawa, Koji

doi:10.2208/jscej.2001.686_121

Cited by 12 publications

(1 citation statement)

References 6 publications

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“…In this tunnel construction, the observation report of tunnel face is implemented for rock mass assessment. A tunnel rock mass classification method, JH method, proposed by Akagi, et al [34], is employed to classify the rock mass. This method uses ten rock parameters of overall state, self-stability, intact rock strength, weathering, joints proportion, spacing of joints, joint aperture, morphology of joints, ground water inflow and ground water corrosion to assess rock mass quality.…”

Section: Rqsmentioning

confidence: 99%

Application of Specific Energy in Evaluation of Geological Conditions Ahead of Tunnel Face

Liu

Sakaguchi²,

Ishizu

et al. 2020

Energies

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In underground construction, especially tunnel building, a detailed knowledge of the geological conditions ahead of the tunnel face is essential for both safety and efficiency of work. Many tunnel collapses have been reported to occur because of a lack of accurate evaluation of the geological conditions. While conventional horizontal boring conducted from a tunnel face provides good accuracy, it is infrequently conducted due to its high cost and time-consuming nature. In addition, the tunnel seismic reflection method has limited practicality owing to the complexity of data processing. This paper presents a new approach based on the specific energy of the mechanical drilling rig to evaluate the geological conditions ahead of the tunnel face. In order to assess the geological conditions, rock mass quality index, buried depth of the tunnel and tunnel deformation investigation were undertaken, and the obtained data were compared to the specific energy. Results from the comparison reveal the evaluation criterion that if the distribution of specific energy in some areas deviates from the distribution of buried depth, it is considered that abnormal geological conditions exist in this area. This work can greatly contribute to the accurate and effective evaluation of the geological conditions ahead of the tunnel face.

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Section: Rqsmentioning

confidence: 99%