Pipeline Asset Management: From Assessment to Prioritized Projects List

Transcription

1 PROGRAM MANAGEMENT INEERING Pipeline Asset Management: From Assessment to Prioritized Projects List TAWWA / WEAT Summer Seminar July 28, 2011 PLANN NING ENG Andrew Hunt, PE Asset Management Project Manager Large Diameter Infrastructure Lockwood, Andrews & Newnam, Inc.

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4 Why Pipeline Asset Management? Many Major Pipelines are Reaching their Useful Life Recent High Profile Catastrophic Failures Strained CIP Budgets GASB Statement 34 Historical cost less depreciation model Modified approach (includes Condition Assessment)

5 What is Pipeline Asset Management?

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7 Steps of Pipeline Asset Management Not Always!

8 Steps of Pipeline Asset Management Data Collection Establish a Risk-Based Prioritization Matrix Identify System Risk Factors Risk Based (consequence of failure) Large vs. small pipe Emergency operations (hospital) Pipeline redundancy (shutdown, criticality) Function Based (likelihood of failure)

9 Common Function-Based Risk Factors Pipe Material Cast iron/ductile iron Concrete Steel Fiberglass HDPE PVC Asbestos Cement No wood stave, cored log, etc. Pipe Exterior Coating Integrity Delaminated Mortar Coating

10 Common Function-Based Risk Factors Broken or Hydrogen Embrittlement of Prestressing Wires in PCCP Split Prestressing Wires Broken Prestressing Wires

11 Common Function-Based Risk Factors Improper Grouting of Joints Ungrouted Interior Joint Ungrouted Exterior Joint

12 Common Function-Based Risk Factors Inadequate Surge Protection Improper Cathodic Protection Collapsed Steel Pipe

13 Common Function-Based Risk Factors Fluctuating Groundwater Table High Internal Working Pressure Excessive External Loading Corrosive Soil Environment What could go wrong?

14 Pipe Segment Condition Assessment CA determines the ability of the pipeline to provide appropriate serviceability Present Future CA Planning Individualistic (old/new; big/small, etc.) Sequencing through prioritization Intuitive or Matrix Procedure (i.e., internal/external, entry, corrosion, etc)

15 Condition Assessment Results Definitive or Comparative Pipeline Life Design Service Life Meeting design conditions with original safety factors Effective Service Life Lower safety factors to end of life End dof Life Borderline inadequate safety factors Current state and conditions affecting that state

16 Asset Management Process System Inventory Identify risk factors Pi Prioritize ii High hrisk kpipes Assessed Condition of Pipes Now Do Something About It!

17 Next Step: Rehabilitation/Replacement Decisions Add CA Results to Prioritization Matrix Identify Highest Risk Pipe Segments Evaluate individual pipe segments Determine Rehab / Replacement Final Goal: Specific Projects for CIP & Budgets

18 Case Study: Rehab / Replace Decision Tools City of Houston 1,300 miles of large diameter water lines 24 to 96 Estimated $50 million annually to address pipes at end of service life Cost Too High Pipe age inaccurate indicator Need: Proactively Identify and Address High Risk Pipe Segments

19 Case Study: Rehab / Replace Decision Tools Transmission Line Condition Assessment Rehabilitation Program (TLCARP) Complete Asset Management Program Achieved advanced approval from Decision Makers

20 Case Study: Rehab / Replace Decision Tools TLCARP Prioritization Matrix Used for Condition Assessment & CIP Development

21 TLCARP Rehab / Replace Decision Tools Build on the CA Prioritization Matrix Evaluate Options for Corrective Action Develop Repair / Replace Decision Protocol Establish a Rehabilitation Planning Matrix Develop Global Unit Prices for Key Elements Carbon Fiber Repair Open-cut Replace

22 Rehab / Replace Decision Protocol Identify Pipe Performance Issues (i.e., Water quality, Leakage, Flow/Headloss Issues) Would rehabbed main deliver required performance? If yes, proceed. If no, then replace. Pipe is structurally sound Pipe is structurally inadequate

23 Rehab / Replace Decision Protocol Pipe is structurally sound Pipe is structurally inadequate Pipe only has water quality issues Pipe has flow, headloss, water quality and/or leakage issues Identify cause of structural deterioration and select semistructural/ structural rehab system Identify cause of water quality issues and select appropriate non structural lining system Pipe has leakage issues Pipe only exhibiting flow, headloss, and/or water quality issues. Identify cause of leakage and select non structural/ semi structural rehab system Identify cause of flow/headloss issues and select non structural/semi structural rehab system

24 Remove & Replace Open-Cut Replacement: Not Always The Best Option

25 Rehabilitation Planning Matrix

26 Rehab Tip for Future Connections/Modifications Difficult to modify = Difficult to repair Consider possible future connections prior to rehab Consider Service Requirements Pressure Limitations Reduction in flow capacity External loads Transient vacuum loads (negative e pressures) es) Raw water vs. Treated water

27 Develop CIP Evaluate Top Ranked Pipelines from CA Prioritization Matrix Apply Each Pipeline: Repair / Replace Decision Protocol Rehabilitation Planning Matrix Develop Conceptual Construction Cost Use Global Unit Costs Re-Evaluate Each Project Nearby CIP Projects Location of Good / Bad Valves Cost vs Available Funding Break project into smaller sections (if necessary)

28 CIP Developed for TLCARP

29 QUESTIONS? PLANN NING ENGINEERING PROGRAM MANAGEMENT Andrew Hunt, PE Project Manager Lockwood, Andrews & Newnam, Inc.

30 Case Study: Using Rehab/Replace Decision Tools Catastrophic Failure: 42 PCCP water main Primary supply line for major repump station Failed from repeated pressure surges 25,000 LF of damaged pipe Minimizing shutdown time was critical

31 Catastrophic Failure

32 Catastrophic Failure Live Petroleum Pipelines

33 Failed Pipe Section

34 Interior Circumferential Cracks

35 Interior Longitudinal Cracks

36 Severe Core Cracking

37 Delaminated Mortar Coating

38 Rehab / Replace Options Considered Construction Cost and Duration Estimated Design Description Final ID Estimated Construction Cost Estimated Construction Duration 42 $9,900, days 1 Remove and Replace 48 $10,200, days Installation and 42 $11,500, days 2 Abandonment 48 $11,700, days 3 Sliplining 36 $8,000, days 4 Rehabilitation with Internal Reinforcement 42 N/A N/A

39 Rehab / Replace Matrix Results Conventional Sliplining * 45

40 Selected Option: Slipline with HDPE Access Pits

41 HDPE Pipe Stringing

42 Case Study Conclusions Design and bidding process complete in 60 days Construction 25,000 LF installed in 4 months 2 months for valve and fitting installation, pipe disinfection and pavement restoration City saved ~ $2 million by choosing Sliplining R/R Decision Tools Simplified and Accelerated Project