What is Yui Landslide Project?
Protecting Lives from Disasters
Disaster Prevention Projects
Landslides are caused by a combination of various factors (topography, geology, geological structures, groundwater, etc.), so there are a wide variety of landslides measures.
These can be divided into control work and restraining work, and these two measures are combined to achieve more effectiveness.
At Yui Landslide Countermeasures projects, we are installing control works such as catchment wells, lateral borings, drainage tunnels to reduce groundwater level, and control works such as maintenance of Caisson piles to directly stop the movement of landslides.
Catchment Wells
23 catchment wells (length between 17 and 61m, diameter of 3.5m) have been constructed and maintained for the purpose of removing deep groundwater.
 【Drainage in water catchment wells】 |
 【Completed Water Catchment Well (Above Ground)】 |
 【Completed Water Catchment Well (Inside)】 |
21 horizontal borings (about 80m in length) have been drilled and maintained for the purpose of removing groundwater.
 【Completed Lateral Boring (with consideration of surrounding landscape)】 |
 【Completed Lateral Boring】 |
 【Drainage from Lateral Boring】 |
 【Drilling of Lateral Boring】 |
Caisson Piles Works
Yui is building and maintaining 61 Caisson piles (length between 37m and 88m, diameters of 5.0m and 6.5m) to directly stop the movement of landslides by using the resistance of the piles.
 【Caisson Piles under Construction】 |
Drainage Tunnels
Drainage tunnels (Yamanaka Drainage Tunnel, length of 768m, and Okubo Drainage Tunnel, length of 712m) are being constructed in the bedrock to remove groundwater deep in the ground using pipes attached to the tunnels.
 【①Tunnel Excavation (Rotor Head)】 |
 【Construction Equipment. From left: shotcreting machine, boring machine, cutting machine (Construction Process: Excavation→Spraying→Rock Bolt)】 |
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 【②Mortar Spraying】 |
 【③Lock Bolt】 |
 【④Inside of the Tunnel (The large area is the water collection room)】 |
The next page explains the effectiveness of the projects.
