Effects of 3-D Fracture Tensor Parameters on Deformability of Fractured Rock Masses

Seongjin Ryu; Jeong-Gi Um

doi:10.7474/TUS.2021.31.1.066

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2021 Vol.31, Issue 1 Preview Page

Original Article

Effects of 3-D Fracture Tensor Parameters on Deformability of Fractured Rock Masses 삼차원 절리텐서 파라미터가 절리성 암반의 변형특성에 미치는 영향

28 February 2021. pp. 66-81

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Abstract

The effects of directional fracture tensor components and first invariant of fracture tensor on deformation moduli and shear moduli of fractured rock masses is analyzed based on regression analysis performed between 3-D fracture tensor parameters and deformability of DFN blocks. Using one or two deterministic joint sets, a total of 224 3-D discrete fracture network (DFN) cube blocks were generated with various configurations of deterministic density and probabilistic size distribution. The fracture tensor parameters were calculated for each generated DFN systems. Also, deformability moduli with respect to three perpendicular direction of the DFN cube blocks were estimated based on distinct element method. The larger the first invariant of fracture tensor, the smaller the values for the deformability moduli of the DFN blocks. These deformability properties present an asymptotic pattern above the certain threshold. It is found that power-law function describes the relationship between the directional deformability moduli and the corresponding fracture tensor components estimated in same direction.

Keywords

Fractured rock mass

Discrete fracture network

Fracture tensor

Deformability

Distinct element method

본 연구는 삼차원 절리텐서 파라미터와 DFN(discrete fracture network) 블록의 변형특성 간의 상관성 분석을 수행하여 절리텐서의 방향성분 및 일차불변량이 절리성 암반의 변형계수 및 전단탄성계수에 미치는 영향을 평가하였다. 확정적 방향성을 갖는 1~2개의 절리군을 사용하여 절리의 빈도 및 길이분포의 변화에 따라 생성한 총 224개의 DFN 블록에 대하여 절리텐서 파라미터가 산정되었다. 또한, 정육면체 DFN 블록에 대하여 개별요소법을 활용하여 서로 직교하는 세 방향으로 변형특성이 추정되었다. 절리텐서의 일차불변량이 증가할수록 변형계수 및 전단탄성계수는 대체로 저감되는 양상을 나타내지만, 감소폭이 줄어들어 일차불변량이 특정 기준값을 상회하면 변형계수 및 전단탄성계수는 거의 일정한 값을 유지하였다. 삼차원 DFN 블록에 대한 지향적 변형특성은 대응하는 방향의 절리텐서성분과 멱함수의 강한 상관관계를 도출하였다.

키워드

절리성 암반

불연속절리망

절리텐서

변형특성

개별요소법

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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 : 31
No :1
Pages :66-81
Received Date : 2021-02-10
Revised Date : 2021-02-22
Accepted Date : 2021-02-24
DOI :https://doi.org/10.7474/TUS.2021.31.1.066

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

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