Bosai Solution ID : JBP00001

Implant™ Levee
Highly Resilient Disaster Prevention Levee

HazardEarthquake Tsunami Cyclone Storm Surge Flood

Solution Purpose
Prevention & Mitigation Recovery

Solution Theme
Infrastructure Technology

Technology Subject
River & Basin Coast Port

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Advantages
Implant Levee is the essential infrastructure to prevent disasters caused by tsunamis and earthquakes.
As its deep-rooted "backbones" are integrated to the Earth, they are highly resistant to grounddisplacement caused by the motion of earthquakes, repeating tsunamis, and other external forces,
serving as a "resilient" disaster-prevention infrastructure.

Solution Illustrated
Major Five Functions of Implant Levee
Implant Levee has major 5 functions as a “resilient” disaster-prevention infrastructure. They areillustrated below as a sample of effect of reinforcement with double sheet pile wall based on theresearch collaboration by Kochi Prefectural Government, Kochi University and GIKEN Ltd.

Background
Conventional "Old-fashioned" Levee
Since ancient times, levees on rivers and coasts have been
constructed by soils, stones or bricks on the ground. Inmodern times, big concrete blocks have come into use insteadof soils but still they are just put on the ground. They can beillustrated as a row of sleeping cows (levees) against attack oflions (tsunamis).

Great East Japan Earthquake
In 2011, terrible power of nature shook the land and washed out a great number of conventional levees
with the loss of 18,500 lives. We can't overlook the fact that disaster prevention infrastructures＜ Downloaded from www.bosai-jp.org ＞

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collapsed at their proudest moment to save lives from the actual disaster. Structures that are installed
into shallow ground are mechanically vulnerable against external forces of earthquake and tsunami. We
should never repeat such a man-made tragedy. If our Implant Levee were used, most of precious lives
could be saved.

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Structural Revolution
Preceded theearthquake by a decade,
GIKEN advocatedImplant Structure forlevees instead ofconventional footingstructure. It was difficult
for civil engineers toaccept Implant Levee
until the earthquake
happened to provefragility of conventional
levees and resilience of
Implant Structure. Thus
in 2012 Implant Levee
started to be adopted
for nationalcountermeasuresagainst the forth-coming
Nankai Megathrust
Earthquakes.

Exposition of the Solution
Implant Structure (Principle)
Implant Structure consists of an allowable structural member that is combined with structural and＜ Downloaded from www.bosai-jp.org ＞

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foundation elements that are pressed-in the ground where they are securely supported by the Earth.
The structure carries horizontal and vertical loads, using the “size of section” and “depth of penetration”. As a result, it exhibits high strength as an aggregate having with individual allowable structuralmembers that are supported by the ground. Therefore, it is highly resistant to ground displacement
caused by the motion of earthquakes, tsunami, and other external forces, serving as a “resilient”
disaster-prevention infrastructure.
Implant Levee (Application)
Implant Levee is an application of the Implant Structure for disaster prevention and mitigation. It has
resilient backbones inside the levee body mainly filled by soils. Backbones are usually tubular pile wallor double sheet pile walls that are highly liquefaction-resistant. Outstanding functions of Implant Levee
are illustrated in the previous section.

Implant Method™ (Construction)
Pile walls
areconstructe
d byPress-in
Methodthatutilises
reactionforce
derived from pre-installed piles to hydraulically push into the ground silently and vibration-free. As allnecessary press-in machinery systematically works on the top of pile walls, it minimises working spaceand eliminates a need for temporary platform even on slope, unlevelled ground or above water. Thus
the Implant Structures can be constructed whilst fully satisfying the Five Construction Principles, which
include consideration of environmental protection, safety, speed, economy and aesthetics in the form of
a balanced equilateral pentagon.

Achievements of Examples
Pevention is Better than Cure
Implant Levee is one of the most resilient levee structures because it was designed to protect lives ofJapanese citizens against the forth-coming biggest ever Nankai Megathrust Earthquakes. Prevention isbetter than cure. The best usage of Implant Levee is to build in advance of disasters. Even if a disasteroccurs before prevention works, the Implant Method can be operated as an emergency measure to＜ Downloaded from www.bosai-jp.org ＞

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cover the lost functions of infrastructures. And when ordinary infrastructures are damaged by a disaster,Implant Levee and other Implant Methods are the best way of recovery and reinforcement for furtherprotection.
Recent Achievements
Kochi Nino, Nii, Tobara and Nagahama coast levee improvement project (Ministry of Land,Infrastructure, Transport and Tourism), Kochi Kokubu-river and Kuma-river levee improvement project (Kochi Civil Engineering Office), Toyohashi-shi tidal defence project (Higashi-mikawa Construction Office), etc.

Road retaining wall of national route 134 in Kamakura along Sagami Bay suffered aging degradation andhas been renovated by Implant Levee without removal of existing road retaining wall (a left photo below).
And in various "build back better" reconstruction projects in Tohoku regions after the Great East Japan
Earthquake, Implant Levees were constructed to improve local resilience for future (right 2 photos
below are projects in Iwate Prefecture).

Corporate Profile
GIKEN LTD.
16F Ariake Central Tower, 3-7-18 Ariake, Koto-ku, Tokyo 135-0063, Japan Tel. : E-mail : international@giken.com
 Website : https://www.giken.com/en/＜ Downloaded from www.bosai-jp.org ＞

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