Inter-regional dialog between history and contemporary houses

-Resource and Disaster-

Hideyuki KOBAYASHI, DR.Eng.

Research coordinator for housing information system,

Resarch center for advanced information technology

Ministry of land and infrastructure management

Material flow and stock of sustaining human settlements

CO2

Human settlementsmountain

forestry

CO2

disasterconstructionrehabilitation

stock of trees stock of timbers

Material flow and stock of sustaining human settlements

- example in Nihonmatsu city(1991) –

CO2

Human settlements280,000m3 of timber

6,000ha forest1,000,000m3 of timbe

forestry

CO2

disasterdemolition

1,660m3 / year

constructionRehabilitation1,183m3 / year

stock of trees

stock of timbers:11,295 buildings (1993), housing 30,000 population

History of disasters : Nihonmatsu-Japan

• Until 1918 : frequently burned by big fire (interval : 20 years in average)

• After 1918 : modernized fire services and instroduction of fire resistant material (clay wall, and rooftile) preventedn the wide spread of fire.

History of disasters : Japan general

• In most cities in Japan, big fire stopped. However, the quite diverse in times:

• Earlist cases : several historical cities, like Nara, Imai (early 17th century)

• Latest cases : some cities are famous of urban big fire in modern times :

Hakodate (1909), Iida(1947), Tottori(1952), Sakata(1976), etc.

• Less frequent earthquakes were usually followed by big fires, causing large number of victims.

Approaches for disaster prevention

• Fire proof houses

(clay wall, rooftile)

• Water channel and fire services

(located at the center of streets, until mobil traffic required to cover them)

• Spatial arrangement

(width of streets, arrangement of greenery)

Modernization

• Timber brace, metal joint

• From strengthening to pure truss structure

• Hiding structural members behind walls

• Prefabrication, and industrialization

• Increase of man-poser cost, relatively decreasing material cost => change of low cost solution

Shaking sensed by houses

• Distribution of strength of houses

Rate of damaged houses

Level of shaking=>

Dis

trib

utio

n%

of

Dam

aged

hou

se

Shaking sensed by houses Co-relation of areal damage rate (timber – steel), Kobe ‘95

Level of shaking=>

% of Damaged steel houses

% o

f D

amag

ed ti

mbe

r ho

use

s

Source: interim report by BRI, 1995.8

Shaking sensed by houses Co-relation of areal damage rate (steel – RC), Kobe ‘95

Level of shaking=>

% of Damaged RC houses

% o

f D

amag

ed s

teel

hou

ses

Source: interim report by BRI, 1995.8

Shaking sensed by houses• Threshold of defferent structures (Kobe ’95)

Level of shaking

Level of shaking=>

% o

f dam

aged

hou

se

Engineering approach:

• Design, only considering elements which can be calculated

(neglecting traditional elements which are difficult to calculate/explain)

• Extension of elements which can be calculated, with more advanced computing capacity

(evaluating traditional elements as far as possible)

Traditional & empirical approach:

• Over-adaptation, in re-constrcution after damage (similar to rehabilitation of injured human body)

• Wholistic way of thinking• Forgetting past disasters in normal re-constr

uction (if 60 years < interval)• Next disaster will attack after previous one i

s forgotten

Traditional Timber House Locality (Liwa/Lampung/Sumatera, 1994)

• Column from G to F

Adaptation: Additional support

for important room Learned from past quake 60 yrs ago

Traditional Timber HouseLocality (Biak/Irian Jaya, 1996, houses survived tsunami)

• Column stuck into Gafter shaken, slunt but still standing

Aceh Traditional Timber House

• Less Damage from Quake/Tsunami• Straight column(250φ), strengthened by thick ‘Lhu

e’90×300• Learned from previous quake/tsunami 200 yrs ago.

0.5m moved from original position

Museum house

Aceh Traditional Timber House

Aceh Traditional Timber House

• Under re-construction ‘Lhue’

Aceh : Colonial Timber Houses

• Timber Platform House on Land• Small timber houses derived, using

12×12 column

Aceh : Vulnerability of structure

• Wall plates are bearing horizontal shaking, without ‘Lhue’

• Column footing on stone does not reach to roof,

Aceh : Invisible details• Carpentry works at joints of timber

Invisible honset working will save buildings

Vulnerability of structure

• Small, but multiple usage, saving material• Specified in latest revision of structural guideline,

after Kobe

Japanese traditional ‘Lhue’, called ‘Nuki’

History of quake in Sumatera• Two sources : (1)Plate boundary and (2)Sumatera f

ault• 1797(8.2), 1822(?), 1833(~9.0),1861(8.5), 1863(?),

1892(7.7), 1893, 1900, 1907(?), 1908, 1909, 1916, 1921(7<), 1926(<7),1933(Liwa), 1935(7.7)

• 1936(7.2), 1942(7.3), 1943(7.3), 1952(6.8), 1964(6.5), 1967(6.1), 1979(6.6), 1984(6.4), 1987(6.6), 1990(6.6), 1994(6.9,Liwa), 1995(7.0), 1997(6.5),2000(7.8), 2002(7.4),2004(9.2),2005(8.7)

• Source : Hilman Natawidjaja 2002

Material flow and stock of sustaining human settlements

From timber to brick

CO2

Human settlementsmountain

forestry

CO2

disasterconstructionrehabilitation

stock of trees stock of bricks

Brick Factories in Aceh

Inside Banda Aceh City(damaged by shaking)

Eastern Coast(operating)

Brick Factories in West Jawa

• Buring rice husks

Aceh : Brick Houses

• Larger in scale, for extended family• Good quality of material and carpentry skill• RC column (25cm), anchored to foundation• 3m as basic distance between colums (short)

Brick (RM) houses still standing in tsunami ruin

Aceh : Brick House (sample)

Brick House in coastal villages, Aceh

Tsunami revealed the inside of structure of rural brick houses, imitating outlooking of urban

(lack of anchor, poor reinforcement etc.)

Strengthening new brick structure

• Usage of re-inforced frame, anchored (250 < diameter) • Appropriate % of cement for bonding (1:3)These have been long disseminated, however

sttel bar and cement are determinant items for total construction cost and they tend to reduce.

Strengthening new brick structure

• Mixed Usage of Brick and Timber

- popular in Bali island

- promoted in Sukabumi

- adopted in Aceh people

c.f. Japanese castle / modern continuous foundation

Strengthening new timber structure

•Clay wall18 m2c.a. 1 million Rupiah(’95)

Still standing in good

Condition(’05)

•Plywood wall21m2 4 unitsc.a. 20 million Rupiah (’96)

Strengthening old timber structure

• Additional members to regist against horizontal force

[Photo : strengthening damaged timber school in Irian Jaya]

Conclusion

• Disaster-resistant buildings are needed not only for human safety, but also for global warming issues

• Engineering approach (evaluation) to traditional solutions will be worth

• Not only contemporary techniques, but also traditional techniques in developed countries are worth to try.

Proposal• Strengthening newly constructed brick/timber hou

ses will be feasible• Strengthening existing timber houses will be feasi

ble• Economical aspect (cost-benefit) of investment for

disaster reduction will be studied. - rough estimation for non-engineered house - precise estimation for engineered house, where as

set management scheme is applied