Effects of Subsidence and Joint Inclination on the Modifications of Hydraulic Conductivities around Mined Panels

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2006 Vol.43, Issue 1 Preview Page Next Page

Effects of Subsidence and Joint Inclination on the Modifications of Hydraulic Conductivities around Mined Panels 침하와 절리의 경사가 채굴적 주변의 수리전도도 변화에 미치는 영향: 윤용균
Yong-Kyun Yoon

28 February 2006. pp. 76-83

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Abstract

To investigate the change of hydraulic conductivities due to the collapse of the overburden above mined panels, a combined finite element model of the deformation of overlying strata and its influence on hydraulic conductivity through applying a relationship between mining induced strains and modifications of hydraulic conductivities is used. To reflect all rock mass conditions ranging intact rock to heavily fractured rocks, RMR is utilized in place of the modulus reduction ratio. As joints are generally inclined, principal hydraulic conductivity directions don\\\'t coincide with the principal stress directions. Thus, joint inclination may have a significant influence on the resulting hydraulic conductivity fields. Results show that post mining hydraulic conductivities are directly related to the mining induced strain fields. Heavy modifications of hydraulic conductivities due to subsidence are limited to a height of about 9m above mined panels. As the inclination of joint increases from 0o to 90o, hydraulic conductivities have been changed and this result shows a significant impact of joint inclination with respect to ground water flow.

Keywords

mining induced strains

hydraulic conductivity

subsidence

RMR

joint inclination

채굴적 상부 지층의 붕괴에 따른 수리전도도의 변화를 조사하기 위하여 변형률 의존성 수리전도도 변화 구성방정식을 포함하는 유한요소법을 사용하였다. 무결암부터 심하게 파쇄된 암반 조건을 반영하기 위하여 탄성계수감소비 대신에 RMR을 사용하였다. 현지 암반에 나타나는 지배적인 절리는 일반적으로 경사져 있기 때문에 주수리전도도 방향과 주응력 방향은 일치하지 않는 경우가 많다. 따라서 절리 경사가 수리전도도 변화에 상당한 영향을 미칠 것으로 생각된다. 본 연구에서 나온 결과는 채굴적 붕괴에 따라 발생하는 변형률은 수리전도도 변화에 직접적으로 영향을 미친다는 것을 보여준다. 모든 채굴적이 굴착된 경우 수리전도도의 변화가 심하게 발생하는 지역은 채굴적 상부 9 m 지점까지 인 것으로 나타났다. 절리의 경사를 0o부터 90o까지 증가시킴에 따라 수리전도도의 값도 변하는 것으로 나타났으며, 이러한 결과는 절리의 경사가 지하수 유동에 상당한 영향을 미친다는 것을 보여준다.

키워드

채굴에 따른 변형률

수리전도도

침하

RMR

절리 경사

References

석탄산업합리화사업단, 1997, 사업단십년사, 석탄산업합 리화사업단, 서울, pp. 296-320.
석탄산업합리화사업단, 1998, 화전지역 철도지반 보강공사 실시설계 지반조사보고서, 석탄산업합리화사업단, 서울, pp. 1-145.
윤용균, 2003a, “RMR에 따른 변형률 의존 수리전도도 변 화 해석”,터널과 지하공간(한국암반공학회지), Vol. 13, No. 1, pp. 44-51.
윤용균, 김장순, 김종우, 2003b, “암반분류변수를 이용한 침하에 따른 수리전도도 변화 해석”, 터널과 지하공간(한국암반공학회지), Vol. 13, No. 4, pp. 321-329.
Bai, M, 1991, Numerical models of fluid flow and solid deformation in fluid saturated media, Ph.D Thesis, The Pennsylvania State University, USA.
Bai, M and Elswotrh, D., 1993, “Modeling of subsidence and stress-dependent hydraulic conductivity for intact and fracture porous media”, Rock Mech. Rock Engng., Vol. 27, No. 4, pp. 209-234.
Bai, M., Meng, F., Elsworth, D. and Roegiers, J.-C., 1999, “Analysis of stress-dependent permeability in nonorthogonal flow and deformation fields”, Rock Mech. Rock Engng., Vol. 32, No. 3, pp. 195-219.
Liu, J., Elsworth, D., Brady, B.H. and Mulhaus, H.B., 2000, “Strain-dependent fluid flow defined through rock mass classification schemes, Rock Mech. Rock Engng., Vol. 33, No. 2, pp. 75-92.
Matetic, R.J., Liu, J. and Elsworth, D., 1995, Modeling the effects of longwall mining on the ground water system, RI9561, USBM, pp. 1-14.
Nicholson, G.A. and Bieniawski, Z.T., 1990, “A nonlinear deformation modulus based on rock mass classification”, Int. J. Min. & Geological Engng., Vol. 8, pp. 181-202.
Obert, L. and Duvall, W.I, 1967, Rock mechanics and design of structures in rock, John Wiley & Sons, New York, pp. 557-560.
Ouyang, Z. and Elsworth, D., 1993, “Evaluation of groundwater flow into mined panels”, Int. J. Rock Mech. Min. Sci. & Geomech. Abstr., Vol. 30, No. 2, pp. 71-79.
Peng, S.S., 1978, Coal mine ground control, John Wiley & Sons, New York, pp. 306-309.
Snow, D.T., 1969, “Anisotropic permeability enhancement of blocky rocks”, Water Resour. Res., Vol. 5, No. 6, pp. 1273-1289.
Witherspoon, F.A., Wang, J.S., Iwai, K. and Gale, J. E., 1980. “Validity of cubic law for fluid flow in a deformable rock fracture”, Water Resour. Res., Vol. 16, No. 6, pp. 1016-1024.

Information

Publisher :The Korean Society of Mineral and Energy Resources Engineers
Publisher(Ko) :한국자원공학회
Journal Title :Journal of the Korean Society for Geosystem Engineering
Journal Title(Ko) :한국지구시스템공학회지
Volume : 43
No :1
Pages :76-83

[1] 석탄산업합리화사업단, 1997, 사업단십년사, 석탄산업합 리화사업단, 서울, pp. 296-320.

[2] 석탄산업합리화사업단, 1998, 화전지역 철도지반 보강공사 실시설계 지반조사보고서, 석탄산업합리화사업단, 서울, pp. 1-145.

[3] 윤용균, 2003a, “RMR에 따른 변형률 의존 수리전도도 변 화 해석”,터널과 지하공간(한국암반공학회지), Vol. 13, No. 1, pp. 44-51.

[4] 윤용균, 김장순, 김종우, 2003b, “암반분류변수를 이용한 침하에 따른 수리전도도 변화 해석”, 터널과 지하공간(한국암반공학회지), Vol. 13, No. 4, pp. 321-329.

[5] Bai, M, 1991, Numerical models of fluid flow and solid deformation in fluid saturated media, Ph.D Thesis, The Pennsylvania State University, USA.

[6] Bai, M and Elswotrh, D., 1993, “Modeling of subsidence and stress-dependent hydraulic conductivity for intact and fracture porous media”, Rock Mech. Rock Engng., Vol. 27, No. 4, pp. 209-234.

[7] Bai, M., Meng, F., Elsworth, D. and Roegiers, J.-C., 1999, “Analysis of stress-dependent permeability in nonorthogonal flow and deformation fields”, Rock Mech. Rock Engng., Vol. 32, No. 3, pp. 195-219.

[8] Liu, J., Elsworth, D., Brady, B.H. and Mulhaus, H.B., 2000, “Strain-dependent fluid flow defined through rock mass classification schemes, Rock Mech. Rock Engng., Vol. 33, No. 2, pp. 75-92.

[9] Matetic, R.J., Liu, J. and Elsworth, D., 1995, Modeling the effects of longwall mining on the ground water system, RI9561, USBM, pp. 1-14.

[10] Nicholson, G.A. and Bieniawski, Z.T., 1990, “A nonlinear deformation modulus based on rock mass classification”, Int. J. Min. & Geological Engng., Vol. 8, pp. 181-202.

[11] Obert, L. and Duvall, W.I, 1967, Rock mechanics and design of structures in rock, John Wiley & Sons, New York, pp. 557-560.

[12] Ouyang, Z. and Elsworth, D., 1993, “Evaluation of groundwater flow into mined panels”, Int. J. Rock Mech. Min. Sci. & Geomech. Abstr., Vol. 30, No. 2, pp. 71-79.

[13] Peng, S.S., 1978, Coal mine ground control, John Wiley & Sons, New York, pp. 306-309.

[14] Snow, D.T., 1969, “Anisotropic permeability enhancement of blocky rocks”, Water Resour. Res., Vol. 5, No. 6, pp. 1273-1289.

[15] Witherspoon, F.A., Wang, J.S., Iwai, K. and Gale, J. E., 1980. “Validity of cubic law for fluid flow in a deformable rock fracture”, Water Resour. Res., Vol. 16, No. 6, pp. 1016-1024.

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

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