Investigation of geometrical representative elementary volumes based on sampling directions and fracture sets
- PDF / 5,056,945 Bytes
- 17 Pages / 595.276 x 790.866 pts Page_size
- 89 Downloads / 133 Views
ORIGINAL PAPER
Investigation of geometrical representative elementary volumes based on sampling directions and fracture sets Ying Liu 1,2 & Qing Wang 1 & Jianping Chen 1 & Xudong Han 3 & Shengyuan Song 1,4 & Yunkai Ruan 5 Received: 26 October 2018 / Accepted: 13 November 2020 # Springer-Verlag GmbH Germany, part of Springer Nature 2020
Abstract This paper reports that the geometrical representative elementary volume (REV) of fractured rock masses is anisotropic, and the geometric shape of an REV is of a complex, irregular geometry. A 3D fracture network model of 98 m × 80 m × 80 m was created using the field information collected from tunnel PD254 at the Maji dam site in China. One hundred random cubes of various sizes with the same sampling direction were selected to assess the volumetric fracture intensity (P32). Changing the sampling direction along the dip direction and dip angle at a 10° increment, the REV size of each sampling direction was inferred using the Wald–Wolfowitz runs test and P32 values. The REV sizes of entire rock masses and each fracture set were calculated, and the results indicated that the REV sizes varied with the different sampling directions. The anisotropy ratio and standard deviation were employed to quantify the degree of the anisotropy of REVs. Based on the results, the anisotropy of REVs for fracture set 2 is the most significant, and that of fracture set 3 is the worst. The relationship between the anisotropy of REVs and fracture sets was discussed; one fracture set, two fracture sets, and three fracture sets were selected randomly from these simulated rock masses to evaluate the characteristics of the anisotropy of REVs. The mean value and the anisotropy of REVs increased with the number of fracture sets. The maximum REV size with a sampling direction was selected as an REV for each fracture set. Four cubes with different directions and different sizes were assembled into an irregular geometry. This geometry can represent the geometric shape of the REV of entire rock masses. Keywords Representative elementary volume . 3D fracture network . Anisotropy . Geometric shape
Introduction Because of the existence of random discontinuities in fractured rock masses, the mechanical, geometrical, and hydraulic
* Jianping Chen [email protected] 1
College of Construction Engineering, Jilin University, Changchun 130026, China
2
School of Geomatics and Prospecting Engineering, Jilin Jianzhu University, Changchun 130118, China
3
Center for Hydrogeology and Environmental Geology, CGS, Baoding 071051, China
4
State Key Laboratory of Geohazard Prevention and Geoenvironment Protection, Chengdu University of Technology, Chengdu 610059, China
5
College of Transportation and Civil Engineering, Fujian Agriculture and Forestry University, Fuzhou 350002, China
properties of rock masses become increasingly complicated (such as discontinuity, inhomogeneity, and anisotropy). The deformation modulus, Poisson’s ratio, fracture intensity, and hydraulic conductivity vary significantly with rock scales
Data Loading...
