Presentation on theme: "Dam Safety Data Management"— Presentation transcript:
1Dam Safety Data Management William Empson, PE, PMPSenior Levee Safety Program Risk ManagerU.S. Army Corps of EngineersRisk Management CenterDam Safety WorkshopBrasília, Brazil20-24 May 2013
2You have the data – what next? ManagementYou have the data – what next?Amanda Sutter, P.E.CEMVSData Management
3PurposePerform timely evaluation of data to assure that unsafe performance of a structure is detected as early as possible.
4ObjectivesLearn various methods of data collection, processing, presentation, evaluation and reporting requirementsIdentify various factors that influence dam safety instrumentation data.
5Components of Data Management CollectionReduction and processingPresentationEvaluationData Management
6Data Collection Schedule Factors affecting schedulePurpose of the instrumentProject conditionsAge of projectLoading eventObserved anomalyAvailability of personnelProject locationFundingCorporate policyFundsNewLeakFlood
7Data Collection Data set should contain Project Instrument ID Instrument readingReadout unitReader’s nameDatePool and TailWeather conditionsUnusual conditionsInstrument damage
8Data Collection Consistency Personnel Manner readings are taken EquipmentLabel instrumentsTrain data collection personnelMultiple readingsCoordination of instrument readings
9Data Collection Data books Data Entry Field sheet Laptop computer Handheld or pocket computer
10Data CollectionEquipment used to monitor instruments should be calibrated and in good operating condition.Good communication is critical between person(s) reading instruments and office personnelThreshold values should be established and furnished to person(s) collecting and transmitting data.
11Reduction and Processing Data Reduction SoftwareCorps Instrumentation DatabasePackage, WinIDPSoftware developed in districtCommercial softwareMicrosoft Excel or AccessSINCOGeoKonGeomation
12WinIDP HQUSACE proponent Based on survey of Districts (1990) DevelopmentHQUSACE proponentBased on survey of Districts (1990)Dam safety instrumentation needsCompatibility with existing databasesConverted to windows 1996Web portal and GIS modules 2003Continually updated; current version 5.5dLatest version added Grapher 7 and modified scheduled tasks for data import and plotting.
13WinIDP: Features User defined formats for input, plots, reports Time dependent constants (repair riser => new elevation)Manual data entry with shared field conditionsData import (can be automated / scheduled)Compatible with Geomation and CSI dataloggersRecalculate by data set or instrumentData edit by data set or instrumentMask data that is questionableBatch plottingNetwork or stand aloneMultiple users (concurrent use)Internet accessible, WebIDP.
14WebIDPRequires internet explorer and internet access - No local installation.Data entryPlotsReports
15WinIDP: Benefits A Good Choice Supported by COE dam safety people Tailored for dam instrumentationUpgrades and costs shared with othersCompatible with other engineering processes and other information systems used in dam safetyProgram is free. Pay as you go for supportDon’t reinvent the wheel – improve the wheel if needed.
16Data Presentation Positional Plots Multiple Plots Correlation Plots Time History PlotsPositional PlotsMultiple PlotsCorrelation Plots
20Guidelines for Presentation Appropriate scaleStandardize formatDisplay relevant field conditionsLocation and cross section on graphsNote events and observations that mayexplain unusual dataAvoid over crowded plots
28Analysis and Evaluation Trends, Patterns and Thresholds Performance PredictionRecent dataHistorical dataField conditions“Reasonable” limitsGuidance given in ERData Management
29Benefits to performance prediction Quick assessment of dam behaviorIndication that data was collected properlyField conditionsAlert that readings are outside expected valuesGuidance given in ERData Management
30Warning for threshold use Will not reveal plugged instrumentOnly as good as data derived fromShould not substitute for thorough data analysisThresholds may be applied duringData collectionData entryData evaluationGuidance given in ERData Management
31Analysis and Evaluation Compare Current Data toRecent dataHistorical data (established trend)InitialField conditionsDesign Prediction / ThresholdsOther instrument typesGuidance given in ERData Management
32Analysis and Evaluation Other considerationsConstruction activities.Maintenance of instrument.Change of procedures.(i.e. temperature correction; esp. concrete)Change of equipment or personnel.Lag time.Guidance given in ERData Management
33Actions after the analyses Document the evaluation.Verify suspect readings and readout calibration.Verify procedures (I.e. different sensitivity setting).Duplicate reading.Notify pertinent personnelVerify with other instrument typeAsk for visual observation of areaModify collection scheduleRequest additional investigationGuidance given in ERData Management
34Actions after the analyses Reporting RequirementsAnnual instrumentation summary and evaluation to DivisionEvaluation to be included in Periodic InspectionsGuidance given in ERData Management
35Instrumentation Planning Predict controlling mechanism (I.e. Pool)Define question to be answered (I.e Cutoff is 90% effective)Select parameter to monitor (I.e. piezometric elevation)Predict magnitude of change (I.e. 50 feet)Select instrument location (I.e. toe of dam)Select instrumentSelect reading frequencyData collection and management“Geotechnical Instrumentation for Monitoring Field Performance” Dunnicliff, 1993“Instrumentation of Embankment Dams and Levees” EM , 30 Jun 1995Begin with a design concern or performance problem.Planning is required to get reliable and effective systems. Do not just try something, you will not be that lucky.Data Management
36ObjectivesLearn various methods of data collection, processing, presentation, evaluation and reporting requirementsIdentify various factors that influence dam safety instrumentation data.
37Perform timely evaluation of data ConclusionPerform timely evaluation of datato assure that unsafe performance of a structure is detected as early as possible.Instrumentation data is a valuable asset for the life of the structure.Backup the data.
46Piezometer Data Evaluation What is observed on the plotProgressive increase in piezometric pressureBehavior not consistent with previous high poolsDownstream piezometers reflect tailwater (expected)PW-08 was typically dry (expected)What factors could be relevantTimeHigh poolBackfill material clogged or collector pipe blockageTemperatureCoal mine treatmentPiezometer tip clogged or riser crackedPrevious falling head tests (5’ fall in 5 minutes in 2003)
47Piezometer Data Evaluation What actions could be takenDo not assume impending failure of the damObserve the area for distressCheck visually for instrument damageNotify project staff, management, and other pertinent staffPerform rising and falling head testsSound bottom of holeUse inflatable bladder to test for breaks in the piezometerInstall additional instrumentationAnalyze wall stabilityIncrease reading frequencyAutomate with alarm calloutPump down drainage manhole and camera inspect the pipeFurther literature research on foundation treatment
48EXERCISE 1: Piezometer Data Evaluation What would be your recommended threshold for PW-08DryTailwater plus 5 feetWhat would be your recommended threshold for PW-09Tailwater plus 5 feetWhich phases of data collection and evaluation could the thresholds be implementedData collection (Automated or Manual)Data entryData plotsData evaluation