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1. Title

Disaster Protection Technology of Traditional Wooden cultural Buildings

ID: DRH 4 Examples of repair with dismantlement.
Hazard: Earthquake , Cyclone/Typhoon
Category:

Transferable indigenous knowledge (TIK)

Proposer: Yasuhiro Araki
Country: JAPAN;
Date posted: 15 January 2008
Date published: 29 August 2008
Copyright © 2008 Yasuhiro Araki (proposer). All rights reserved.

Examples of repair with dismantlement.

Contact

Yasuhiro Araki
Research Fellow,
National Research Inst. for Earth Science and Disaster Prevention (NIED),
Earthquake Disaster Mitigation Res. Ctr. (EDM)
araki@edm.bosai.go.jp

2. Major significance / Summary

Japanese traditional wooden cultural buildings have been survived for long times.
The key technology for surviving may be “regular maintenances with appropriate intervals”, and this technology brings the sustainability of buildings.

3. Keywords

Sustainability of buildings ; Regular maintenance with appropriate intervals


II. Categories

4. Focus of this information

Transferable indigenous knowledge (TIK)

5. Users

5-1. Anticipated users: Administrative officers , National governments and other intermediate government bodies (state, prefecture, district, etc.) , NGO/NPO project managers and staff , Experts , Architects and engineers , Environmental/Ecological specialists

5-2. Other users:

6. Hazards focused

Earthquake , Cyclone/Typhoon

7. Elements at risk

Buildings , Cultural heritages


III. Contact Information

8. Proposer(s) information (Writer of this template)

Yasuhiro Araki
Research Fellow,
National Research Inst. for Earth Science and Disaster Prevention (NIED),
Earthquake Disaster Mitigation Res. Ctr. (EDM)
araki@edm.bosai.go.jp

9. Country(ies)/region(s) where the technology/knowledge/practice originated

JAPAN;

10. Names and institutions of technology/knowledge developers

11. Title of relevant projects if any

12. References and publications

13. Note on ownership if any


IV. Background

14. Disaster events and/or societal circumstances, which became the driving force either for developing the technology/knowledge or enhancing its practice

Wooden cultural buildings like temples are one of the symbols of emperor's power in ancient times. These buildings are also the base of the believer’s belief. So these buildings are required to exist permanently. However, Japan suffers many strong earthquakes that might damage those buildings, and Japan has warm and humid climate, which might deteriorate members (= timber) of those buildings. These cultural and natural backgrounds developed the preservation and restoration technologies of wooden buildings in Japan. Today wooden cultural buildings like temples are still the bases of the believer’s beliefs. Moreover, these buildings have high cultural value. Therefore, wooden cultural buildings are required to continue to exist permanently. In addition, the development of the structural design technology that can quantitatively evaluate Japanese traditional structural elements is also required.


V. Description

15. Feature and attribute

(1)The preservation technology of wooden buildings The following two points are indispensable to the preservation technology of wooden building.

1)Regular maintenance with appropriate intervals. Almost all of the materials used for the construction of those cultural buildings are wood. These materials might deteriorate with the passage of time, since the climate is warm and humid in Japan. Therefore, all or several parts of the buildings are checked whether they need to be repaired. Generally, all parts of the cultural wooden buildings in Japan are dismantled and repaired approximately every 300 years, and meanwhile roofs are repaired approximately every 100 years (See Chart1).

Chart1 : EX. of Toshio-dai-ji

 

2)Maximum reuse of members of buildings (= timber) and minimum replace of damaged members. At the time of maintenance, the members that have been damaged seriously are replaced with new ones. Usually most of the damaged members are such part as the roofing materials and the edge of the columns where these members suffered damages easily. On the other hand, other members located at other parts with good condition remain in use even if they have been used for hundreds of years. At the time of replacing materials, maximum reuse of members of buildings (= timber) and minimum replacement of damaged members are considered as much as possible. For example, when the inside of a column is found out damaged at the time of dismantlement, the inside part, where the member is damaged, will be removed, and a new material substitutes for the part removed. Therefore, outside of the columns don’t change (Fig.1).

Fig.1 Examples of maximum reuse and mimum replace

(2)Quantitative evaluation of Japanese traditional earthquake resistant elements Today, by using Earthquake-resistant design techniques such as “Limit Strength Method” and “earthquake response analysis”, it is possible to quantitatively evaluate Japanese traditional earthquake resistant elements such as “restoring force for stabilizing made by column rocking”, structural performances of “nuki” (= a kind of joint of column and beam), and “tuchi-kabe”, which enable structural designers to evaluate quantitatively the structural performances of the buildings. Designers can evaluate earthquake resistant performances of those cultural wooden buildings as well as other modern architectures like Steel and RC buildings. They can reinforce the building if necessary. Designers can also evaluate the effect of past reinforcements which have not been evaluated quantitatively so far.

Although these technologies are the results of the development of the earthquake proof engineering in recent years, it should be noted that they are simply secondary technologies of the preservation technology that has a long history.

 

Fig 2. Example of analysis models like "Limit Strength Method" and "earthquake response analysis"

 

Fig 3. Example of "nuki" (=a kind of joint of column and beam)

 

Fig. 4 Example of "tuchi-kabe"

Fig. 5 Restoring force for stabilizing made by column rocking

 

1) Suo Kokubunji HP : http://www5.ocn.ne.jp/~suoukoku/index.html

2) Toshodaiji HP : http://www.toshodaiji.jp/

 3) MORI Yusuke, SUZUKI Takashi, IZUNO Kazuyuki and TOKI Kenzo, Effect of Axial Force Fluctuation in Supporting Columns on Earthquake Response of Traditional Wooden Japanese Temple, Journal of JAEE, Vo1.7, No.1, 2007 (in Japanese)

4)Kiuchi Osamu, “Design technique of contemporary carpenters”, Shin-kentikusha

5)Forestry and Forest products Research Institute HP, http://ss.ffpri.affrc.go.jp/labs/etj/setugo/setugo9804/9611Dento/9611Dento.html

16. Necessary process to implement

(1)The preservation technology of wooden buildings

1) (Structural and )Deterioration investigation of the buildings. At first, the levels of deterioration of members are investigated. By these investigations, designers estimate members that should be replaced at the time of dismantlement.

2) Planning for restoration considering maximum reuse of members and minimum replacement of damaged members. The repair plan is proposed based on the deterioration investigation. At the time of planning, maximum reuse of members and minimum replacement of damaged members are considered.

3) Checking the dismantled members during the dismantlement At the time of dismantlement, the deteriorations of the members which can’t be found at the deterioration investigation are checked, and if necessary, these members are added to the repair plans.

4) Rebuilding: After the repair, the buildings are rebuilt.

(2)Quantitative evaluation of earthquake-resistant elements.

1 ) Structural investigation Structural performances are also investigated at the same time as investigating deterioration. In these investigations, the earthquake-resistant elements of the traditional building of Japan are picked up.

2 ) Modeling for applying to structural design techniques Earthquake-resistant elements which picked up are modeled. These modeled elements are applied to structural design techniques such as “Limit Strength Method” and “earthquake response analysis”. Designers can evaluate earthquake-resistant performances quantitatively by using these methods.

 

Fig.6 Toshodaiji Kyoto                                  Fig.7 Analysis model of Tosho-dai-ji

 

Fig.8 Toshodaiji Kondo                                                      Fig.9 Analysis model of Tosho-dai-ji

 

 

Takenaka Corporation HP http://www.takenaka.co.jp/syaji/daiji/daijitop.html

17. Strength and limitations

(1)The preservation technology of wooden buildings

1) “Regular maintenance with appropriate intervals” “Regular maintenance with appropriate intervals” enables buildings to survive for long time. Although they are damaged by the earthquake, if the buildings have the records about building plans, they can restore original form of buildings.

2) “Maximum reuse of members of buildings” “Maximum reuse of members of buildings” also enables buildings to restore original form of buildings.

These technologies are considered to be connected with sustainability of buildings.

(2)Quantitative evaluation of earthquake-resistant elements. The designer comes to be able to evaluate earthquake resistant performances  for the assumed force of the cultural wooden building as well as other modern architectures. The designers can reinforce the buildings if necessary.

18. Lessons learned through implementation if any


VI. Resources required

19. Facilities and equipments required

Usually at the time of dismantlement of the buildings like temples, temporary housing is needed to protect the entire building from wind and rain (Fig.10).

 

Fig.10 Examples of temporary housing

Moreover, spaces where the exchanged materials are processed and dismantled members are kept are needed.

New materials (Timber) are needed for replacing damaged members.

20. Costs, organization, manpower, etc.

In order to dismantle, repair and rebuild the building, the carpenters who are expert at building and repairing cultural buildings are needed. They are usually called “Miya-daiku” in Japan (Fig.11).

 

Fig. 11 Miya-daiku

At the time of deterioration investigation and structural investigation, experts in deterioration of the timber and structure of the cultural wooden buildings are needed.

Organization in which carpenters, experts and parties concerned in the building discuss are also needed

 

1) Higashi Honganji HP : http://higashihonganji.jp/nikki/nikki.html

2) Suo Kokubunji HP : http://www5.ocn.ne.jp/~suoukoku/index.html


VII. Message from the proposer if any

21. Message


VIII. Self evaluation in relation to applicability

22. How do you evaluate the technology/knowledge that you have proposed?

It is a technology/knowledge that

23. Notes on the applicability if any


IX. Application examples

No.1

    E1-1. Project name if available

    “Toshodaiji Kondo Heisei Dai shuri”
    (= Large Scale repair with dismantlement of Toshodaiji Kondo)


    E1-2. Place

    〒630-8032 13-46 Gojo mati, Nara city, Nara prefecture, Japan  


    E1-3. Year

    1998~2009


    E1-4. Investor

    Nara Prefectural Board of Education


    E1-5. People involved

    (1)The carpenters who are expert at building and repairing cultural buildings are needed.
    (2) At the time of deterioration investigation and structural investigation, experts in deterioration of the timber and structure of the cultural wooden buildings are involved.
    (3) Parties concerned in the building are also involved.
    (4)Organization in which carpenters, experts and parties concerned in the building discuss are also needed.


    E1-6. Monetary costs incurred


    E1-7. Total workload required

    Chart2 is Schedule for repair. It takes about 10 years to complete.


    E1-8. Evidence of positive result

    (Tangible) 

    Because of the damages of Hyogo-ken Nanbu Earthquake in 1995, this temple needs large scale of repairs with dismantlement and improvements of structural performances. This time the latest structural analysis technologies are applied to this temple.

    The deterioration and structural investigation enable designers to evaluate deterioration and structural performances of the temple and propose the repair plans considering for maximum reuse of members and minimum replace of damaged members.

    Earthquake-resistant design techniques enable structural designers to evaluate the structural performances of the buildings quantitatively.

    Designers can also evaluate the effect of past reinforcements which have not been evaluated quantitatively so far.

    Fig.12 Examples of deterioration and structural investigation]

     

    Fig.13 Examples of analysis of current structural performances

    (intangible) Preservation technologies such as “Regular maintenance with appropriate intervals” and “Maximum reuse of members of buildings” are considered to be connected with sustainability of buildings (Fig.14).

    Fig.14 Examples of repair with dismantlement (1)

     

    Fig.14 Examples of repair with dismantlement (2)

     

    1) Takenaka Corporation HP http://www.takenaka.co.jp/syaji/daiji/daijitop.html



X. Other related parallel initiatives if any

Message


XI. Remarks for version upgrade

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