Shigen-to-sozai, Vol.118, No.10,11, pp.675-680.
Characteristic Evaluation of Fracture in Solid from Flow Rate-Time Record under Constant Injection Pressure
Yasuhiko SOTOIKEa, Kohei YAMAOKAb and Yoshiaki MIZUTAc
| a. NICHIBOI, 4-7-28, Itatsuke, Hakata-ku,
Fukuoka 816-0088, Japan b. Kamifukuura Architectural Laboratory, 2-1-15, Hiromiashi, Kure, Hiroshima 737-0106, Japan c. Professor, Dr., Faculty of Engineering, Yamaguchit University, Tokiwadai, Ube 755-8611, Japan |
| Fluid injection test using a borehole for
permeability of rock mass, such as Lugeon
test, is to evaluate the average permeability
of rock mass around the borehole, as the
Lugeon value or the coefficient of permeability,
although those values do not directly represent
the feature or characteristic of the fracture/joint
in rock mass. However, a distinctive mark
of the fracture is one of the significant
factors, which reflect the apparent permeability,
and it may be possible to find a distinctive
fracture quality by observing the trend of
test data. In order to examine whether it is possible to evaluate a unique property of fracture in a solid, longitudinal percolation tests for fluid seepage in wooden samples, which contain longitudinal thin plane slit or slits were carried out. Characteristic evaluation of the fracture in the sample was tried through explanation of the flow rate-time curves under constant fluid injection pressure, which were obtained from the laboratory tests. The explanation is based on the numerical calculations of both the seepage analysis and elastic displacement analysis. Possibility of simple and economical evaluation of fracture characteristic is suggested from the results and then, one method for evaluation of fracture, characteristic by using the least in-situ data and comparing it with numerical simulation result, is proposed. |
| KEY WORDS: Fluid Injection Test, Fracture Characteristic, Wooden Sample, Numerical Simulation, Constant Injection Pressure |