Function Diagnosis Method to Improve Earthquake Resistance of Water Supply Facilities

Yasuhiko SATO Japan Water Research Center

Contents

• Situation of Earthquake-proofing in Japan• Function Diagnosis and Evaluation Manual• Performance Indicators on management of

water supply services in Japan• Conclusion

Situation of Earthquake-proofing in Japan

Current Situation in Japan

※ ProbIems in drinking-water utilities in Japan :－ Lack of financial and technical resources, and－ Decrepit and vulnerable to earthquake and other

disasters

1413,0006.925 March,2007

NotoPeninsula

8130,0006.823 October,2004

NiigataChuetsu

43(Except heavy damage)

1,270,0007.217 January, 1995

Hyogoken-Nanbu

Restoration(Days)

Interruption(Households)

MagnitudeDateName of Earthquake

Ratio of Earthquake-proof Facilities

20% 30%14%

Rat

io o

f Ear

thqu

ake-

resi

stan

ce (%

)

The Ministry of Health, Labour and Welfare has set up the target that the ratio of earthquake –proof of main facilities and distribution mains should be 100% by 2025.

Ratio of Earthquake-proof : 100% by 2025

Percentage of Projects Planned for Enhancing Earthquake Resistance of FacilitiesPopulation

ServedProjectsPlanned

NotPlanned

PlanningRatio

More than 500,000 17 5 77.2%More than 200,000 33 39 45.8%More than 100,000 45 63 41.7%Less than 100,000 63 155 28.9%Water Wholesaler 44 42 51.2%Total 202 304 39.9%

Japan Water Research Center prepared the “Waterworks Facilities Function Diagnosis Evaluation Manual” which can contribute to earthquake-resistant water supply facilities.

Function Diagnosis and Evaluation Manual

Purpose of Function Diagnosis and Evaluation Manual

Purpose : To enable drinking-water utilities to independently evaluate.

－ Evaluating the current function of existing water supply facilities.

－ Preparation of plans for improving facilities that performance has declined.

・ Commissioned by the Ministry of Health, Labour and welfare.

・ Distributed to prefectures and utilities in July, 2005.・ Available to download from web site of the Ministry.

http://www.mhlw.go.jp/topics/bukyoku/kenkou/suido/index.html

Function Diagnosis

Present Future

Func

tion

of fa

cilit

ies

Present function of facilities：a

c

Room for functionimprovement : d

e : Required function

Upgrade

Required level of function

Decline in function : b

ｰ Grasp the Present function of facilities (a) or the Estimated function of facilities (c)

ｰ Determine the Room for function improvement (d)

Function Diagnosis and Evaluation Procedures

Function Diagnosis

Evaluation ProcedureEvaluation Category

Evaluation of currentfunction

Evaluation of functionsatisfaction

Formulation ofimprovement plans

Individual function diagnosis

End

Overall function diagnosis

Setting of functionImprovement methods

Setting of functionimprovement targets

Has required level of Function been met ?

Judgment of function diagnosis result

Yes

No

Evaluation of Current Function(Distribution System)

Function Category Evaluation Indexes

BasicPerformance

Hydraulicfunction

1.Securing ratio of optimal hydrodynamic pressure(%) 2.Securing ratio of optimal hydrostatic pressure (%) 3.Distribution reservoir storage time (hr)4.Total storage time (hr)

StructureEarthquakeresistance

8.Water distribution facilities earthquake resistance (-)9.Available water capacity in emergencies (L)10.Ratio of installed emergency stop valve (%)11.Ratio of earthquake-resistance pipeline (%)

Redundancy 12.Distribution water capability in emergencies (-)

Maintenance Certainty24.Adequacy of drawing management (-)25.Saving of maintenance (-)26.Adequacy of maintenance (%)

※ Items on earthquake-proofing :“Diagnosis of Facilities’ Earthquake-resistance”

Diagnosis of Facilities’ Earthquake Resistance

Category For water pipe bridgeItems Category Weight Factor Point Remarks

GroundType Ⅰ 0.5

○Type Ⅱ 1.5Type Ⅲ 1.8

Pipe TypeDuctile cast iron 1.0

○Gray cast iron 2.4

Joints

Expansion, anti-slip-out mechanism

type0.5

○

Other joints 1.0

Seismic Intensity

Scale

５ 1.0○

Levels according to the Japan Meteorological Agency

６ 2.2７ 3.6

EarthquakeResistance

High 14＞○Medium 14～28

Low 28＜

100

80

60

40

20

0

Score of overall functiondiagnosis points : 61

Distribution Distribution Distribution DistributionReservoir A Reservoir B Reservoir C Pump A

Indication and Examination of Evaluation Results

Score of individual function diagnosis The lowest

This should be improved !

Performance Indicators on management of water supply services in Japan( ISO / TC224 )

Undertakings of the Japan Water Research Center

－ PIs would be established in accordance with the standards of the each country.

－ JWWA published “Guidelines for the management and assessment of drinking water supply service” in January 2005.

－ The Guideline defines 137 PIs, including indicators on earthquake countermeasures, that is specified in Japan.

JWRC has performed an analysis of PIs in utilities in Japan, and PI histograms were draw up.

Histograms(Ratio of earthquake-proof pipeline)

A utility can use this histograms to compare its own PIs to those of the other utilities, in order to objectively assess its own position within nationwide framework.

95th percentile 30.1%80th percentile 12.6%75th percentile 10.3%Median 4.1%25th percentile 1.5%20th percentile 1.1%5th percentile 0.2%

Conclusion

Result of Undertakings (I)

Name of Earthquake Date Magnitude Interruption

(Households)Restoration

(Day)

NiigataChuetsu

23 October,2004

6.8 130,000 About30

Disastered Experiences (Hyogoken-nanbu, Niigata Chuetsu)

NiigataChuetsu-oki

16 July,2007

6.8 59,000 About10

Study of an Effective Maintenance Method to Minimize Damages

Preparation of Manual

30%UP : (Present : 17%)Ratio of earthquake-proof pipeline

Result of undertakings (II)

0.00.20.40.60.81.01.21.41.61.82.0

0 20 40 60 80 100Ratio of Pipe with Low Earthquake Resistance (%)

Dam

age

Rat

io (N

umbe

rs/k

m)

Relationship between Ratio of Pipeline with Low Earthquake-resistanceand Damage Ratio

City A (Hyogo)

City K (Hyogo)

City T (Hyogo)

City M (Hyogo)

City O (Niigata)

City G (Niigata)

City N (Hyogo)

Pipeline with lowearthquake-resistance- Gray cast iron pipe- High density polyvinyl

chloride pipe - Asbestos cement pipe

※ Earthquake damage reduction must be due to the improvement of earthquake resistance of pipelines and the preparation of earthquake disaster measure manuals.

ConclusionPreventive maintenance of the facilities is important.

－ Function diagnosis according to function diagnosis and evaluation manual must be carried out, and the effort must be made to enhance facilities functions.

－ Analysis of the water supply facilities assets based on PIs is very useful to demonstrate the necessity for ensuring the earthquake-resistance of facilities.

－ In Japan, earthquake-proofing of facilities was conducted based on past experience, and the effect has begun to appear against earthquake damage.

Thank you for your attention.