Calculation of Key Blocks’ Safety Ratio based on Discontinuity Analysis

Eunsung Kim; Sanghun Noh; Sang-Soon Lee

doi:10.7843/kgs.2024.40.3.101

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2024 Vol.40, Issue 3 Preview Page

Calculation of Key Blocks’ Safety Ratio based on Discontinuity Analysis 불연속면 분석에 근거한 쐐기블록 안전율 계산

30 June 2024. pp. 101-108

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Abstract

A system with the ability to recognize potential key blocks during tunnel construction by analyzing the rock face was developed in this study. This system predicts the formation of key blocks in advance and evaluates their safety factors. A laser scanner was used to collect a three-dimensional point cloud of the rock face, which was then utilized to model the excavation surface and derive the joint surfaces. Because joint surfaces have specific strikes and dip angles, the key blocks formed by these surfaces are deduced through iterative calculations, and the safety factor of each key block can be calculated accordingly. The model experiments confirmed the accuracy of the system’s output in terms of the joint surface characteristics. By inputting the joint surface information, the calculated safety factors were compared with those from the existing commercial software, demonstrating stable calculation results within a 1% error margin.

Keywords

3D rock analysis

Discontinuity analysis

Key block

Safety

Point cloud

터널 공사중 발생 가능한 쐐기블록(Key block)을 막장관찰 중 인지하여 전방으로 형성되는 쐐기블록을 예상하고, 안전율을 확인할 수 있는 시스템을 개발하였다. 막장관찰시, 레이저 스캐너를 이용하여 암반면의 3차원 점군을 수집하고, 이를 근거로 굴착면을 형상화한 후, 암반 절리면을 도출한다. 절리면은 주향과 경사각을 가지고 있으므로, 절리면들의 조합을 통해 형성되는 쐐기블록을 반복 계산을 통해 도출하고, 각 쐐기블록의 안전율을 계산한다. 모형실험을 통해 시스템의 절리면 특성 산출의 정확성을 확인하였고, 절리면 정보를 입력하여 계산되는 기존 상용 소프트웨어의 결과값과 비교하여 개발 프로그램이 오차 1%이내로 계산 결과를 얻을 수 있음을 확인하였다.

References

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Goodman, R.E. and Shi, G. (1985), “Block Theory and its Application to Rock Engineering”, Prentica-hall.

Kliche, C.A. (2018), “Rock Slope Stability”, Society for Mining Metallurgy & Exploration (SME).

Kim, Y.M. (1999), “Analysis for Effccts of Slope Failure Behavior by Finite Element Method”, J. of the Korean Geotechnical Society, Vol.15, No.5, pp.19-28.

Sung, H.S. and Koh, J.S. (2024), “Image-Data-Acquisition and Data-Structuring Methods for Tunnel Structure Safety Inspection”, J. of the Korean Geotechnical Society, Vol.40, No.1, pp.15-28.

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Information

Publisher :The Korean Geotechnical Society
Publisher(Ko) :한국지반공학회
Journal Title :Journal of the Korean Geotechnical Society
Journal Title(Ko) :한국지반공학회 논문집
Volume : 40
No :3
Pages :101-108
Received Date : 2024-06-20
Revised Date : 2024-06-20
Accepted Date : 2024-06-20
DOI :https://doi.org/10.7843/kgs.2024.40.3.101

Journal of the Korean Geotechnical Society ISSN:1229-2427(Print) 2288-646X(Online) 한국지반공학회 논문집

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