Abstract: The present invention provides a hydraulic test system, by which it is possible to select a proper position and to select a reliable measurement interval corresponding to said position, to obtain information for preventing retention or leaving of the equipment in the borehole, and to observe the conditions in front and lateral directions by a single BTV at the same time and at wide angle of view without adjusting focal point. On the tip of a measurement pipe to be inserted into a borehole, a waterproofing cylinder with a transparent window oriented for simultaneously observing in both the front and lateral directions is mounted, and there are provided illumination units for illuminating in front direction and side walls and a borehole television set equipped with a ball lens, spherical mirror lens or matched convex pair of lens system in said cylinder, which forms a virtual image of an object in front direction and a reflected virtual image of an object in lateral direction on almost the same plane.

Abstract: A low-water-pressure-controlled hydrologic test using a measurement pipe containing an inner packer which is equipped with a water pressure gage at its tip is disclosed. Some water is poured into the measurement pipe in advance so as to diminish the pressure head difference between the in-pipe pressure and the pore water pressure of the rock concerned. The permeability coefficient is obtained by measuring changes in the recovered water level in terms of pressure changes. In the case of an aquiclude, the inner pressure is raised by expanding the inner packer, the permeability coefficient being obtained by detecting the changes in inner pressure. Thus, the method allows a permeability test to be conducted continuously at various depths. In addition, it helps to shorten the measurement time to a remarkable extent and enables the rock condition to be investigated without departing from the natural condition.