MEASURING METHOD AND DEVICE FOR HYDRAULIC SLACK REGION OF ROCKBED AROUND CAVITY

摘要

PURPOSE: To extract only change of the water permeability due to influence of the slack by pouring water into a measuring division of a trial bored hole excavated around a cavity, and executing the water permeation test while the quantity of water supplying having stabilzed is assumed as the pseudo saturated condition. ;CONSTITUTION: A trial bored hole is excavated, and a tip packer 1 and an at-hand packer 2 are installed, and resin is poured into the packers 1, 2. The air pressure of a compressor 26 is controlled to a constant value by a pressure regulator 23, and the test water in a tank 21 is poured into the measuring division C, and the gap water pressure is measured by pressure gauges 5-8. The water pouring pressure is set by the valve of the regulator 23 and water is poured continuously, which is lasted until the rate of flow is stabilized, and water supply is made even after confirmation is made that pseudo saturation is obtained, and the quantity of water supplied and the pressure of pouring water are measured. From these pieces of data, the water permeability is calculated and compared with the permeability value previously determined through boring prior to excavation of the rock so that its slack is evaluated. Thereby slack region can be evaluated quantitatively.;COPYRIGHT: (C)1994,JPO&Japio