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
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.
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 !
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%
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.