Retaining wall works: Concrete retaining walls are built on the lower part of a slope to directly suppress a collapse of that part and also to check coming-down collapsed soil and stop it before houses.

Soldier piles and lagging works : Steel piles are driven into a slope to restrain the collapse of the surface soil layer. Lagging is placed between piles to prevent downward movement of eroded soil. This construction method can be applied not to destroy existing vegetation.

Grating crib works : Concrete frames are laid on a slope, within which plants grow to protect the slope from weathering and erosion. It is also possible to directly suppress slope collapse by using the frames in combination with ground anchors, etc., or to allow trees remaining on the slope to be retained by adjusting the arrangement of the frames.