Characterization of the Hydraulic Property and the Numerical Flow Models of Fractured Rock Mass

• Published in: SOILS AND FOUNDATIONS Vol. 38; no. 4; pp. 57 - 70
• Main Authors: Kobayashi, Akira, Fujita, Tomoo, Chijimatsu, Masakazu
• Format: Journal Article
• Language: English
• Published: Tokyo Elsevier B.V 01.12.1998; The Japanese Geotechnical Society; Japanese Geotechnical Society
• Subjects: anisotropy; Applied sciences; Buildings. Public works; Earth sciences; Earth, ocean, space; Engineering and environment geology. Geothermics; Engineering geology; Exact sciences and technology; Geotechnics; heterogeneity; in-situ test; numerical model; permeability; rock mass; seepage (IGC: F4/G7/G13); Soil mechanics. Rocks mechanics; in-situ test; numerical model; seepage (IGC: F4/G7/G13); anisotropy; permeability; heterogeneity; rock mass; Rock mechanics; Theory; In situ test; Pressure distribution; Borehole; Hydraulic conductivity; Injection; Permeability; Rock mass; Water leak; Anisotropy; Jointed rock; Numerical simulation; Free flow; Hydraulic properties
• ISSN: 0038-0806; 1341-7452
• DOI: 10.3208/sandf.38.4_57

To apply the general flow theory by Barker to the conventional in-situ hydraulic tests, the type curves for the constant head and constant rate tests for a general condition are derived with the semi-analytical method. The results of the real in-situ hydraulic tests are examined by the type curves. By arranging the results and considering the different test results, it is found that the hydraulic characteristics can be systematically inferred. As the second subject, whether or not the conventional continuous and discontinuous numerical models can represent the flow behavior such that is observed at the in-situ test is examined. The flow of a single borehole test simulated through the various numerical models is tested by the type curve. The effect of the anisotropy and heterogeneity of the model on the dimension and the hydraulic conductivity obtained by matching with the type curve is tested, and the relation of the variance of the dimension and hydraulic conductivity to the models is examined. By using the examination results, the proper available models for the site of interest here is discussed. The process presented in this paper will be very helpful in selecting the numerical model for a real problem because it is seen from the results that some models show a distinctive tendency in the dimension.