抄録
To construct dams on highly permeable rock foundations rationally and economically, the accurate evaluation of permeability of dam foundations is required. When we perform Lugeon water-test(LWT), the most popular in-situ permeability test for dam foundations, in highly permeable rock foundations with high injection pressure, the water flow from an injection hole becomes the turbulent flow and the flow rate is not directly proportional to the injection pressure. Therefore, equivalent Lugeon value is dependent upon the injection pressure.
On the other hand, when the water flow is laminar, the flow rate is directly proportional to the injection pressure and we have no trouble in calculating the Lugeon value. Besides, because the'hydraulic gradient of seepage in dam foundations is low and can be supposed to be almost laminar, laminar flow resistance law is necessary to estimate the amount of underseepage.
In this paper, we have developed high viscosity fluid test (HVFT) to obtain the laminar flow resistance law of highly permeable rock foundations by injecting viscous fluid instead of water.
