Performance-based Operations & Maintenance of Movable Storm Surge Barriers in The Netherlands. Arno Willems MSc Iv-Infra

Transcription

1 Performance-based Operations & Maintenance of Movable Storm Surge Barriers in The Netherlands Arno Willems MSc Iv-Infra

2 Introduction 1993 TU Delft Applied Mathematics Probability, Risk and Statistics 1999 Aveco de Bondt Civil Engineering 2001 Ministry of Infrastructure & Environment Risk Analysis 2006 Iv-Infra Risk Analysis & Systems Engineering Ports & Waterways

3 Contents Safety Standards for (movable storm surge) barriers in NL Performance-based Operations & Maintenance Plan Do Check Act Current situation Q & A

4 Water Act Dutch Water Act Management and use of water Prevent and, where necessary, reduce flooding Safety Standards for dike rings: Average overtopping probabilities per year 1/250 per year

5 Safety levels Safety level New Orleans: 1/100 years 1/250 per year

6 Movable barriers Maeslant barrier Inflatable Ramspol dam Hartel barrier Hollandsche IJssel barrier Eastern-Scheldt barrier Haringvliet sluices

7 Maeslant barrier Expected water levels are continuously calculated by a hydraulic model If a water level of 3.00 meters above NAP is anticipated for Rotterdam, or 2.90 for Dordrecht, the Storm Surge Barrier computer - the Command and Support System (Dutch acronym BOS) instructs the Control System (BES) to shut the barrier. The barrier shuts (and opens again after the storm) fully automatically

8 Maeslant barrier Expected water levels are continuously calculated by a hydraulic model If a water level of 3.00 meters above NAP is anticipated for Rotterdam, or 2.90 for Dordrecht, the Storm Surge Barrier computer - the Command and Support System (Dutch acronym BOS) instructs the Control System (BES) to shut the barrier. The barrier shuts (and opens again after the storm) fully automatically

9 Safety Standard for movable barriers Failure of movable (storm surge) barrier Overtopping P o < Safety Standard Failure to close P fc < 0,1 Safety Standard Structural failure P sf < 0,01 Safety Standard Requirements to the performance of the barrier in terms of Reliability, Availability and Maintainability (RAM)

10 Condition report Water Act, 4. Monitoring and Assessment, section : The water authority shall submit a report on the general structural condition of a primary flood defence structure to the Provincial Executive every six years. Problem: no direct relation between Operations & Maintenance and RAM performances of movable barriers Will we pass the next test six years later?

11 Performance-based O&M In order to demonstrably and sustainably comply with the Water Act, the Ministry of Infrastructure always needs to be in control Performance-based Operations & Maintenance (POM) for storm surge barriers was developed in 2005 POM: Reliability, Availability and Maintainability (RAM) centered O&M

12 Act: RAM reqs.

13 Act: RAM reqs. Derive RAM requirements from Water Act Safety Standards, using probabilistics and hydraulic modeling if needed Maximum allowable probability of failure (on demand): 1/100 Derive R, A and M requirements on component level

14 Act: RAM Analysis Perform RAM analysis: FMECA, Fault Tree analysis, CCF analysis, human factor analysis, software reliability, etc.

15 Plan: Analysis Perform Operations & Maintenance analysis Perform RCM analysis Fill Maintenance Management system Write O&M procedures and instructions Make agreements (by contract) with maintenance contractors and suppliers Tune organization & management to meet M-requirements (2-4 fte extra) Appoint Reliability Manager who is responsible for RAM performance of the barrier(s)

16 Do: O&M Operations & Maintenance Execute O&M in accordance with O&M plan using the Maintenance Management System Train operational and maintenance staff on a regular basis

17 Do: O&M

18 Check: Monitor Monitor RAM performance Register unscheduled outages Register component failures: type, cause and duration Monitor components conditions Monitor human behaviour Execute audits: check maintenance contractors and suppliers performances on compliance with contractual agreements

19 Act: RAM analysis Close the circle: (adjust) RAM analysis Update component failure probabilities and MTTR s with historic (failure & maintenance) data using Bayesian Statistics Update Fault Tree and recalculate the barrier s RAM performance If RAM requirements are met: optimize O&M costs If RAM requirements are not met: adjust O&M or even adjust the system physically

20 Current situation Nowadays: POM is being applied to most of the moveable storm surge barriers in the Netherlands POM is still developing: we are currently improving CCF modeling, software reliability calculation, human error calculation and data mining We recently developed a decision framework to determine the level of depth of applying POM to any object managed by the Dutch Ministry of Infrastructure and the Environment

21 Questions?