To provide a borehole excavation method capable of easily reducing a viable bacteria count in excavated water used in an excavation process and obtaining a core and a groundwater sample with reduced microorganism contamination without requiring a complicated system.
A borehole excavation system 10 comprises: a boring machine 100 which obtains a core sample of base rock; and excavation water circulation means 400 which supplies the boring machine 100 with excavation water. The excavation water circulation means 400 has an ultraviolet sterilization device 600 which sterilizes the excavated water; and an excavation water switching section R which switches whether or not to supply an inside of a borehole with the excavation water in an excavation water circulation route. The excavation water switching section R does not supply the inside of the borehole with the excavation water for a predetermined period of time in a preparation stage of a borehole excavation work but circulates the excavation water to the excavation water circulation route.
SHINGU SHINYA
AOSAI DAISUKE
MIZUNO TAKASHI
| JP2008008066A | 2008-01-17 | |||
| JP2008008067A | 2008-01-17 |
Hirukawa Masanobu
Takashi Koyama
Hideo Sugai
Kenji Aoki
Hiroshi Nagisawa
Akira Yonezawa
Yoshiaki Minami
Takehiko Katayose