17/03/2017. Contents. Solutions. Customer s Needs. How Trenchless Rehabilitation Depends on Effective Condition Assessment. Performance.

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1 Contents How Trenchless Rehabilitation Depends on Effective Condition Assessment 1. Range of Trenchless Rehabilitation Technologies 2. Need Engineering Methodology to ensure effective and economic application select most appropriate solution for customer s needs performance and risk Tom Sangster C.Eng., M.I.C.E. General Manager FAE/Downley Consultants JV, Abu Dhabi Trenchless Middle East Dubai, UAE 14 March Pipeline Condition Assessment 1. What is it? 2. Why do we need it? 3. How do we do it? E M I R A T E S 4. Example Solutions REHABILITATION RENOVATION use existing pipe structure REPLACEMENT no use of existing pipe structure REPAIR use existing pipe structure Non-structural Structural Off-line On-line Joint sealing Cement mortar lining Close-fit sliplining Open Cut Trenchless Sliplining Mechanical joint sealing Epoxy/PU Sprayed lining resin lining Spirally PRP wound lining CIPP Woven hose lining Trench Narrow trench Mole ploughing Directional drilling Pipejacking & microtunnelling Earth piercing Pipe bursting Pipe splitting Pipe eating/ reaming Open trench (e.g. emergency repairs) GRP panel lining Auger boring Pipe ramming Pipe extraction 23 options How to decide? Engineering Methodology to: Ensure effective and economic solution Consider customer s needs Performance Risk Service Life Select solution to meet these needs Customer s Needs Performance Risk Service Life 1

2 Performance Serviceability level and reliability of service to customers 24/7 service availability No service interruptions No flooding or blockages Drinking water quality Hydraulic Performance of Network Sufficient pressure & volume (water) Sufficient capacity and velocity (sewers) Structural Performance of Network Pressure capability Non-revenue water Inflow/Infiltration Risk Service Life Permanent (>50 years) Minimal maintenance during service life Further renovation in future to extend life Temporary (<50years) Interim until planned replacement To permit delaying capital expenditure on replacement or upgrading Maintenance during service life Pipeline Condition Assessment What is it? Inspection and investigation provides data. Condition assessment is the process of analysing inspection data so that it becomes management information which creates a platform for management decisions and actions to strengthen the business and improve its performance. Done properly it requires a considerable depth of engineering knowledge and experience together with a clear understanding of the economic drivers of the utility business. INSPECTION REHABILITATION INSPECTION CONDITION REHABILITATION ASSESSMENT 2

3 INSPECTION/ INVESTIGATION DIAGNOSTIC TOOLS CONDITION ASSESSMENT ASSET MANAGEMENT DATA EXPERT ANALYSIS ACTIONABLE INFORMATION Increasing cost and certainty Decreasing risk When solutions become clear after early steps, subsequent steps may be left out Desk Study Design, specification, as-built drawings, soil information Survey-level Investigation. Non-disruptive Leak detection, acoustic measurement, external electrical investigation Invasive/Disruptive Investigation Internal/external electromagnetic, ultrasonic, stiffness Destructive Testing Coupons, pipe sections removed SOLUTION Replace Repair Reline Defer Identifies likely failure modes and necessary investigation works Identifies areas of pipeline with deterioration requiring further investigation to quantify Locates and quantifies defects and deterioration in pipe; corrosion, leaks, etc. Confirms investigation findings and provides remaining service life data Engineering condition assessment defines optimum Asset Management approach to maximise service life at lowest cost and risk Pipeline Condition Assessment Why do we need it? Reduction in Risk Deferral of Capital Expenditure 3

4 Desk Study Design, specification, as-built drawings, soil information Identifies likely failure modes and necessary investigation works Foundation for any condition assessment project Pipeline Condition Assessment How do we do it? Critical task requiring considerable engineering expertise and experience to undertake properly Causes of problems, additional data requirements and the range of feasible solutions are defined Existing network information is analysed to gain a clear understanding of the operational and maintenance history of the network being investigated as well as constraints on the range of works that may be undertaken Agree with Client on the operational, serviceability, performance and failure criteria for the network after renovation Identify risk through the relationship between likelihood and consequence of failure. Acoustic Wave, Soil Chemistry, Resistivity, local external inspection, Leak Noise Correlators CCTV, Laser, Sonar, Broadband Electromagnetic, Remote Field Eddy Current, Ultrasonic, Acoustic Leak Detection, Electro Scan Survey-level Investigation. Non-disruptive Invasive/Disruptive Investigation Destructive Testing Coupons, pipe sections removed Identifies areas of pipeline with deterioration requiring further investigation to quantify Locates and quantifies defects and deterioration in pipe; corrosion, leaks, etc. Confirms investigation findings and provides remaining service life data Field Investigation Field investigation has two purposes: To fill the gaps in information available from the desk study To identify sources and causes of problems and defects It is important not to rush into field investigation because it is costly. Understand what information is needed and design the investigation programme to obtain it enough but not more. 4

5 Time 10 minute - 1 week Temp Salinity PPT 17/03/2017 Inspection Pressure Mains What information is needed? Find leaks Identify corrosion Establish wall stiffness/thickness Establish coating condition What is pipe material & failure mode? DI & CI -localised corrosion AC uniform loss of stiffness PE deformation, fusion joints GRP deformation PCCP wire corrosion External May be small sample only Needs thoughtful planning to target high risk locations No disruption to operation Internal Full length therefore 100% coverage Higher cost May disrupt operations Inspection Gravity Mains A well-designed and properly executed CCTV inspection is the core of successful gravity sewer inspection and is often sufficient for assessment. Provides 100% coverage (subject to blockages or protruding laterals) Laser profiling, sonar, LIDAR, Electro Scan, gyroscopic mapping and salinity surveys can be used where more information is required. Include laterals and manholes Inspection Gravity Mains Manhole Survey Salinity Survey Water Main Inspection Acoustic Wave To prioritize the requirement of CCTV inspections or rehabilitation in a network, salinity measurements are conducted to determine which network section needs further investigation. Salinity probes are inserted in prior selected MH and log the salinity of the effluent for up to 14 days. Data is collected and evaluated to identify areas which require further investigation. Salinity Acoustic Wave measures average wall thickness over intervals Best suited to AC pipe Also useful survey-stage for metallic pipe materials Noise Source 100 m to 200 m 5

6 Water Main Inspection Broadband Electromagnetic GRP & Plastic Pipes Laser Survey Potential Surveys Combined Profiler CCTV+Laser+Sonar Measures electrical potential of pipeline relative to soil Locates areas of defective coatings and active corrosion Applicable to electrically continuous metallic & prestressed concrete pipes Can use cell to cell method for discontinuous pipelines Hydraulic Modelling Condition & Performance Assessment Take the field inspection data along with the desk study information and assess the condition of the pipelines and the effect of this on their performance. Develop rehabilitation/renovation solutions, asset management plans and budgets. Model outputs: Discharge in Links Water Level in Links Velocity in Links Water Level in Nodes Pumping ratio Discharge through weirs Pipe Filling Flooding Maps Pressure in Pipes Sediment transport 6

7 Effect of Pit Depth on CI Pipe Strength Failure Envelope for CI & AC Pipe w W 2 p + 1 P Consider design and safety factor in pressure and bending Condition Assessment PCC Pipes Bathtub Curve Risk curves developed through 3D Finite Element Analysis to identify risk levels in prestressed concrete pipes SOLUTION Replace Repair Reline Defer Engineering condition assessment defines optimum Asset Management approach to maximise service life at lowest cost and risk Reduction in Risk Deferral of Capital Expenditure 7

8 DN1250 AC Rising Main DN1250 AC Rising Main DN1250 AC Rising Main DN1250 AC Rising Main The Condition Assessment Process transforms data into actionable information Understand the Existing System Determine What Information and Where Investigation is Needed Investigate/Inspect Assess the System Condition and Performance Make Asset Management Decisions Asset Management Drivers QUALITY Serviceability levels Risk Management QUANTITY Non-revenue water SERVICE RELIABILITY Maximise service life REVENUE & COSTS Operation & maintenance cost Capital efficiency 8

9 Thank You for Your Attention! FAE - Downley Consultants Ltd Abu Dhabi UAE : +971 (2) 644 : : info@alelweet-eng.com : : tom.sangster@downley.com Mobile: WINCHESTER, UK E M I R A T E S 9