Patents and Utility Models
Karuwaza Sakkun
Overview of the simplified drilling system
In recent years, groundwater drainage works has become more important than ever. That is because the collapses of natural slopes / cut and embankment slopes occur frequently due to increase in rainfall intensity and the local concentration of heavy rain, which are caused by the changes in the global environment.
Horizontal boring, which is a typical construction method for the drainage works, is generally carried out by a rotary percussion-type boring machine. However, it has some problems with the difficulty to use when enough space for setting cannot be found, its transportation becomes a heavy task and prolongs the construction period, and, furthermore, higher expenses results because of it.
"Karuwaza Sakkun", the simplified drilling system, is a new construction method. It was devised as the drilling method for horizontal boring planed at the length of up to about 30m. This system is quite practical where is too narrow to set or transport a large boring machine and at emergency places such as slope disaster sites.
Since this system is made by combining compact and lightweight parts, it can be carried by man-power and needs only 1.2m width x 2.0m length space to drill. Furthermore, since it can be set in a quite short time, construction cost is going to be low.
To utilize this system effectively as a maintenance technology for expressways and to promote high quality maintenance in collaboration, we concluded an agreement regarding technical cooperation with "Nexco-Maintenance Tohoku Company Limited".
Corrugated perforated pipe
Overview of the corrugated perforated pipe
This is effective as the hole retention pipe for water collection boring and underground culverts for landslide countermeasure works. Compared to the existing perforated pipes using VP and GP, it has remarkable water collecting effects.
The perforated pipe so far has the following problems:
・It has normal cylinder shape and its water collecting capacity is low. When water pressure is weak, it rather repels groundwater.
・It becomes a flow path for groundwater when it is completely full, However, in talus slopes, crushed zones, and crack forming zones, the collected groundwater can flow out through its holes.
Meanwhile the corrugated perforated pipe, due to its corrugated shape, its outside becomes a path for groundwater by itself to increase inflow to its holes, and its inner forms a groundwater flow path with no hole and prevents outflow to the outside.
It is very effective in crack developing slopes, talus slopes, crushed zones.
