Stress-path and Stress-mode Analyses of a Circular-shaped Shaft Excavated in Various In-situ Rock Stress States

Sang-Chan Park; Hyun-Koo Moon

doi:10.12972/ksmer.2014.51.6.794

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2014 Vol.51, Issue 6 Preview Page Next Page

Research Paper

Stress-path and Stress-mode Analyses of a Circular-shaped Shaft Excavated in Various In-situ Rock Stress States 암반 응력조건에 따른 원형수직구 굴착시의 응력경로 및 응력모드 분석

31 December 2014. pp. 794-807

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Abstract

In-situ stresses change continuously as the depth of the shaft increases. Various in-situ stress conditions are classified using In-situ principal stress mode defined by the ratio of horizontal to vertical stress and the ratio of horizontal stresses. And the characteristics of in-situ principal stress ratio relating to stress condition are analysed. Secondary principal stress mode is used to classify the principal stresses states acting on the shaft wall after excavation according to the magnitude and direction of the principal stresses. And stress-path and stress-mode analyses are performed by using analytic solution and 3-dimensional numerical method for a circular-shaped shaft excavation with various in-situ stress conditions. With analysis of stress-path, correlation between In-situ principal stress mode and Secondary principal stress mode is estimated. Also, the effects of rock mass condition and support state on the stress-path and stress-mode during the shaft excavation are analysed.

Keywords

Shaft

Stress-path

Stress-mode

Ratio of horizontal to vertical stress

Horizontal stress ratio

수직구는 심도에 따른 초기응력 조건이 계속 변화하는 특징을 갖는다. 암반내 다양한 초기응력 조건을 측압계수와 수평응력비를 이용한 초기주응력모드로 분류하고 초기주응력비가 갖는 응력상태의 특징을 분석하였다. 굴착으로 재형성되는 수직구 벽면의 2차주응력을 크기와 방향에 따라 2차주응력모드로 분류하고, 원형공동에 대한 이론해와 3차원 수치해석법을 이용하여 다양한 초기응력 조건에서의 원형수직구 굴착에 따른 응력경로와 응력모드 분석을 수행하였다. 주응력 평면에서의 응력경로 분석을 통하여 초기주응력모드와 2차주응력모드와의 상관성을 평가하였다. 또한, 암반조건과 보강조건이 수직구 굴착시의 응력경로와 응력모드에 미치는 영향을 분석하였다.

키워드

수직구

응력경로

응력모드

측압계수

수평응력비

References

Bae, S.H., 2005, Characteristics of Initial Rock Stress State in Korean Tectonic Provinces by Hydraulic Fracturing Stress Measurement, Ph. D. Dissertation, Seoul National University, p. 224.

Choi, S.O., 1997, “Characteristics of in-situ stress regime measured by hydraulic fracturing technique and its application on tunnel design,” Tunnel & Underground Space, Vol. 7, pp. 323-333.

Choi, S.O., Park, C., Synn, J.H. and Shin, H.S., 2008, “A decades's experiences on the hydrofracturing in-situ stress measurement for tunnel construction in Korea,” Proc. of 2008 Spring Conference of Korean Society for Rock Mechanic, Seoul, pp. 79-88.

Hoek, E. and Brown, E. T., 1980, Underground Excavations in Rock, The Institution of Mining and Metallurgy, 44 Portland Place, London W1, England, p. 527.

Itasca Consulting Group, Inc., 2009, Fast Lagrangian Analysis of Continua in 3 Dimensions User's Guide, FLAC3D Ver. 5.0, Minneapolis, Minnesota, USA.

Park, S.C. and Moon, H.K., 2011, “A Numerical Study on the Prediction of Displacement Behavior at the face of a Shaft,” J. of the Korean Institute of Mineral and Energy Resources Engineers, Vol. 48, No. 3, pp. 323-334.

Synn, J.H., Park, C. and Lee, B.J., 2013, “Regional Distribution Pattern and Geo-historical Transition of In-situ Stress Fields in the Korean Peninsular,” Tunnel & Underground Space, Vol. 30, No. 6, pp. 457-469.

Information

Publisher :The Korean Society of Mineral and Energy Resources Engineers
Publisher(Ko) :한국자원공학회
Journal Title :Journal of the Korean Society of Mineral and Energy Resources Engineers
Journal Title(Ko) :한국자원공학회지
Volume : 51
No :6
Pages :794-807
Received Date : 2014-10-10
Revised Date : 2014-12-10
Accepted Date : 2014-12-19
DOI :https://doi.org/10.12972/ksmer.2014.51.6.794

Journal of the Korean Society of Mineral and Energy Resources Engineers ISSN:2288-0291(Print) 2288-2790(Online) 한국자원공학회지

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