Groundwater status logging method and device

摘要

PROBLEM TO BE SOLVED: To perform a logging operation precisely and efficiently in the depth direction inside an excavated hole by a method wherein an elastic packer is attached to the whole outer circumference in the intermediate part of a water passage in a probe and water in a set amount is pumped up for a set time from the inside of the hole or water in a set amount is supplied to the inside of the hole. SOLUTION: A probe 1 is inserted into an excavated hole, an elastic packer 5 which is attached to the outer circumferential face is brought into contact with the whole circumferential face of a hole wall, and water which is stored inside the hole is pumped up by a storage pump 17a. As a result, new underground water flows into the probe 1 from the through hole 2. When the water flows out from a through hole 3, a flow rate per unit time is measured by a running-water ultrasonic sensor which is built in the probe, and a logging controller 11 performs a logging operation sequentially. After that, a logging cable 7 is unreeled, and the elastic packer 5 comes into sliding contact with the wall face of the hole. While the passage of the underground water on the outer circumferential side of the probe is being regulated, the probe 1 is lowered sequentially inside the hole. Then, the flow rate inside the probe of the underground water is measured continuously, and the existence of a water passage is logged on the basis of a change in the flow rate. Inversely, when the water inside the hole is small, water in a set amount is poured into the hole, a vertical flow is generated inside the hole, and the existence of the water passage is logged.