History and development of the Kankyo Pile Method

The Kankyo Pile Method uses preservative and anti-termite treated timber to reinforce the ground. It was developed by Kanematsu Sustech and has been installed in over 45,000 buildings. It has won awards including the Global Environment Award and the Eco Mark Award.

This page introduces the background and history of the development of the Kankyo Pile Method, including why and how wood is used for ground reinforcement.

1. Background of the Kankyo Pile Method

Until around 2010, cement and steel pipes were used for ground improvement in housing in japan, and timber was rarely used. Here's why we developed the Kankyo Pile Method.

環境パイル工法開発の背景_1

Forests cover much of Japan. If they are not properly thinned, forests will become unhealthy, such that young trees cannot grow, and they cannot absorb as much CO₂ as they should. Thinning and afforestation are essential, but they are expensive. It’s also important to use the thinned wood effectively.

環境パイル工法開発の背景_2

Timber has been widely used as the main material for buildings since ancient times. Timber is also used to reinforce soft ground. Famous examples are the stone walls of Venice and Saga Castle, and the Marunouchi station building of Tokyo Station.

環境パイル工法開発の背景_3

However, Timber has not been used much for ground reinforcement recently. People also worried about the durability of timber, such as corrosion and termites, and the unknown bearing capacity of timber.
The idea that wood rots was deeply rooted and there was not enough evidence to change it.

環境パイル工法開発の背景_4

Kanematsu Sustech (formerly Kanematsu Nissan Norin) had two divisions: the Wood & Housing Materials Division, which handled research and development of wood preservative and anti-termite treatment technology and treated wood, and the Geo-tech Division, which performed foundation reinforcement work.

2. Development of the Kankyo Pile Method

Against this backdrop, we developed the “Kankyo Pile Method”, which uses our own preservative and anti-termite treatment on domestic thinned wood and casts it into the ground as a improvement material.

Development of Kankyo Pile Method_1

Timber deteriorates due to two main causes: corrosion from wood-decay fungi and infestation by termites. Wood-decay fungi and termites can’t live in water, so damage is unlikely below the groundwater level. But areas above the groundwater level can be damaged.
To prevent timber damage from wood-decay fungi and termites, chemicals are injected into the timber in a special kiln, which works whether or not there is groundwater.

Development of Kankyo Pile Method_2

Field and indoor tests on timber that has undergone a preservative and anti-termite treatment process have been conducted, and the results confirm the efficacy of the treatment.
In field tests, treated and untreated materials were placed underground in termite-infested areas. The results confirmed that the untreated materials caused damage, while the treated materials remained intact.
In laboratory tests, we have confirmed that the chemical has a long-lasting effect. This was confirmed by repeatedly wetting and drying the material to accelerate deterioration and by exposing test specimens that are equivalent to 60 years to termites and decay fungus.

Development of Kankyo Pile Method_3

The bearing capacity of the material was verified through load tests, which involved driving timber pile into the ground and measuring the amount of settlement after applying a load. By conducting these load tests at multiple locations in Japan, we were able to gain valuable insights into the bearing capacity characteristics of the timber pile.

Development of Kankyo Pile Method_4

The “Kankyo Pile Method” was developed by aggregating test results of preservative and anti-termite performance and bearing capacity, and obtaining performance certification from a third-party organization.

3. Current status of the Kankyo Pile Method

It has been over 15 years since the Kankyo Pile Method was first developed. In that time, both the construction result and the recognition of the method as an effective approach have significantly improved. Recently, we have been the recipients of an increasing number of awards in recognition of our philosophy and efforts related to the “Kankyo Pile Method”.

環境パイル工法による多くの賞を受賞

The Kankyo Pile Method has resulted in increased demand for domestic timber, a revitalization of the domestic forestry industry, and a reduction in CO₂ by effectively utilizing domestic timber, including thinned timber. In recent years, we have received numerous awards in recognition of our efforts.

4. Timeline

BC

Timber has been used as a ground improvement material since ancient times

History(BC)

1950~

Ground improvement with timber declined

2005

The development of the Kankyo Pile Method began

2009

Certified for performance of the Kankyo Pile Method at the General Building Research Corporation of Japan (GBRC), a general incorporated foundation

2010

Eco Mark obtained as Kankyo Pile material

Eco Mark obtained as Kankyo Pile material

The Kankyo Pile Method society established in October

Kankyo Pile Logo

Achieved 1,000 buildings constructed

2012

Certified for performance of the Kankyo Pile Super Method at the General Building Research Center (GBRC) of Japan, a general incorporated foundation

Chairperson’s Award
from the Japan Housing and Wood Technology Center (JHWTC) for Housing and Wood Promotion Commendation

2014

Achieved 5,000 buildings constructed

2015

Wood Design Award 2015
Lifestyle Design Category Winner

Wood Design Award  2015

2016

Achieved 10,000 buildings constructed

Japan Resilience Award 2016

Japan Resilience Award 2016

2018

Achieved 20,000 buildings constructed

2020

Achieved 30,000 buildings constructed

2021

Eco Mark Award 2020

Eco Mark Award 2020

Technical evaluation of Kankyo Pile material by The Society of Materials Science, Japan

Technical evaluation of Kankyo Pile material by the Society of Materials Science

9th Good Life Award
from Ministry of the Environment

9th Good Life Award

2022

30th Global Environment Award

30th Global Environment Award

5th EcoPro Award

5th EcoPro Award

Achieved 40,000 buildings constructed

Related link

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