Numerical Study on Vertical Stress Estimation for Panel Pillars at Room and Pillar Mines

Dong-Ho Yoon; Jae-Joon Song

doi:10.7474/TUS.2020.30.5.473

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2020 Vol.30, Issue 5 Preview Page Next Page

Original Article

Numerical Study on Vertical Stress Estimation for Panel Pillars at Room and Pillar Mines 주방식 광산의 패널 광주 수직응력 추정을 위한 수치해석 연구

31 October 2020. pp. 473-483

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Abstract

This paper examines the vertical stress change concentrated on mine pillar which occurs due to the stress disturbance from opening excavation at room and pillar mine by FLAC3D, a finite difference method (FDM) software. The mesh size combination is decided with a careful consideration of relative error and run-time, then its performance is verified. A series of numerical analyses is conducted and the vertical stress at central pillar was observed for the test cases of 1×1 to 11×11 mine pillars, 40 m to 320 m depth with 40 m difference. The results show that the vertical stress of pillar approaches to the similar value with the value estimated by tributary area theory(TAT) when the development area (N_P) is increased or the height of overburden (H_OB) is decreased, while it is overestimated in the opposite case. Furthermore, it also represents that the vertical stress factor (VSF) converges to a specific value when the depth is increased whille keeping the development area identical.

Keywords

Underground mine

Room and pillar mining

Mine pillar

Vertical stress

Numerical simulation

본 연구에서는 3차원 유한차분법(FDM) 프로그램인 FLAC3D를 이용하여 주방식 채광장을 모사하고 채굴적 형성에 의한 현지응력 교란으로 광주에 집중되는 수직응력의 변화를 분석하였다. 오차율과 해석시간을 고려하여 적절한 조합의 요소망 크기를 선정하고 지류론 암반을 모사하여 요소망 조합과 개발 심도에 따른 해석 성능을 검증하였다. 본 해석에서는 개발 영역 내에 1개(1×1)~ 121개(11×11)의 패널 광주가 생성되도록 채굴적을 형성하여 가장 높은 수준의 응력집중이 발생하는 중앙부 광주의 상부 수평단면에 작용하는 수직응력을 측정하였다. 40 m~320 m까지 40 m 단위로 굴착심도를 변경하여 동일한 과정을 반복 수행하였다. 해석 결과, 개발 규모(N_P)가 클수록, 개발심도(H_OB)가 작을수록 중앙부 광주의 수직응력 값이 지류론 추정값에 가까워지는 것을 확인하였다. 또한, 개발 규모가 작고 대심도인 경우에는 지류론에 의한 추정 시 수직응력이 과대평가될 수 있으며, 동일한 개발규모인 경우 심도가 증가할수록 수직응력계수(VSF)가 일정한 값으로 수렴하는 경향이 있음을 확인하였다.

키워드

지하광산

주방식 채광법

광주

수직응력

수치해석

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Information

Publisher :Korean Society for Rock Mechanics and Rock Engineering
Publisher(Ko) :한국암반공학회
Journal Title :Tunnel and Underground Space
Journal Title(Ko) :터널과 지하공간
Volume : 30
No :5
Pages :473-483
DOI :https://doi.org/10.7474/TUS.2020.30.5.473

Tunnel and Underground SpaceISSN:1225-1275(Print) 2287-1748(Online)한국암반공학회

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