Water Industry Seismic Guidelines And Practice Updates
Water Industry Seismic Guidelinesand Practice UpdatesMay 2, 2019
Outline Introduction Seismic Design Framework– Identify Service Priorities– Establish Level of Service Goals– Establish Design Earthquake– Evaluated Project Specific Seismic Hazards– Establish Design Standards and Methods– Design for Seismic Risk Mitigation2
Seismic hazards are widespread“Today, approximately 91percent of Americans live inareas subject to naturaldisasters or terrorism”(Ripley, 2009).The United States GeologicalSurvey (USGS) estimates thatover 50 percent of the landmass in the contiguousUnited States would beaffected by at least strongshaking (MMI VI level ofshaking) from relativelyinfrequent ground motionsfrom earthquakesFigure 14.1. 2014 probabilistic seismic hazard map of the contiguous United States showsthe predicted levels of earthquake shaking severity in terms of modified Mercalli intensityindex for 2 percent probability of exceedance in 50 years (Jaiswal et al, 2015).The modified Mercalli intensity(MMI) scale indicates the severityof shaking to the observed effects(Jaiswal et al., 2015).3
Source: nasa.gov
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Some of the good industry referencesPipelines(O’Rourke & Liu, 2012)(ALA, 2005)Facilities(SFPUC, 2014)(FEMA, 2012)7
Fukushima Nuclear Plant Crisis“Nuclear crisis man-made, not‘an act of god’: experts“Quake guidelines for nuclear plants, revised by theNuclear Safety Commission in September 2006,essentially order power companies to design plantswithout compromising safety in case of earthquakes‘that can be expected no matter how rare.’ Theonly place in the guidelines where tsunamis arementioned – the last page of the 14-pagedocument”“The guidance is not very specific The wording ismeant for seismic experts I am a nuclear engineer,not a quake expert. I didn’t understand theguidance very much, so I asked other committeemembers to use words people understand. Butthey didn’t listen The guidance is useless” –Kunihiko Takeda, Chubu University
SEISMIC DESIGN FRAMEWORK9
Seismic design framework[Discussion focused on AWWA M41 Proposed Chapter]AWWA M41 Chapter 14.Seismic Design Guidelinesfor Ductile Iron Pipe[release with next manual]Seismic framework steps:1.2.3.4.Identify service prioritiesEstablish level of service goalsEstablish design earthquakeEvaluate project specificseismic hazards5. Establish design standards andmethods6. Design for seismic riskmitigation
Identify service priorities Identifying Critical CustomersWater Sector Interdependencies (Source: 2010 Water SectorSpecific Plan) (DHS, 2015)11
Identify service priorities Understanding Infrastructure Components– understand the various components of the system– know how the system operates hydraulically Identify Infrastructure to Serve CriticalCustomersPlanning for water systems as an important part of thebuilt environment, should consider both the broaderand specific needs of the community as part of theidentification of required critical customers andassociated critical water infrastructure.The process needs to take into consideration thecomplete system of infrastructure required to conveywater from the source to the service connection.12
Identify service priorities Evaluation processIt can be as straightforward as having a critical system element that is known to be vulnerableup to complete system evaluations that require a much greater level of effort and resources tocomplete the work. A practical approach to complete that work is to evaluate seismic resilienceas part of the normal master planning activities that occur for water systems. Additional steps as part of a master planning activity for buried pipelines recommended by NIST(2015) include the following:– In GIS, superimpose the pipeline distribution system onto maps of the scenario hazard (peak groundvelocity, liquefaction potential, and landslide potential).– Use empirical relationships developed by the American Lifelines Alliance (ALA) to predict the number ofbreaks and leaks in the pipeline system.– Estimate the time required to repair the predicted number of breaks and leaks based on historical crewproductivity data and restore system functionality.– Consider the anticipated damage states of dependent systems (transportation, liquid fuel, etc.).13
Seismic level of service goalsYou have to understand what you’retrying to achieve“If you don’t know where you’re going, any roadwill get you there”– Lewis Carroll14
LOS goals based on guidance fromthe Oregon Resilience Plan15
WWSP seismic level of service goalsSystem ComponentsWWSP LOS GoalsOregon Resilience PlanGuidanceIntake & Raw Water Facilities50% capacity w/n 48 hrs *(25% capacity w/n 24 hrs)Source 20-30% (0-24 hrs)Source 50-60% (1-3 days)Source 80-90% (1-2 wks)Treatment Plant50% capacity w/n 48 hrs *(25% capacity w/n 24 hrs)Source 20-30% (0-24 hrs)Source 50-60% (1-3 days)Source 80-90% (1-2 wks)Terminal Storage ReservoirSame as ORPTransmission 80-90% (0-24 hrs)Transmission LinesSame as ORPTransmission 80-90% (0-24 hrs)AppurtenancesSame as ORPTransmission 80-90% (0-24 hrs)TurnoutsSame as ORPTransmission 80-90% (0-24 hrs)Oregon ResiliencePlan OperationalLevel of ServiceGuidance - TargetStates of Recoveryfollowing anEarthquakeORP – Oregon Resilience Plan* Full capacity when electrical power, transportation and other required infrastructure capacity restored16
Seismic level of service goals Classification of Infrastructure – Options:– ALA & ASCE Pipelines SeismicSubcommittee– Oregon Resilience Plan (ORP)“The backbone water system would be capable of supplying key community needs,including fire suppression, health and emergency response, and communitydrinking water distribution points, while damage to the larger (non-backbone)system is being addressed.” (OSSPAC, 2013)Pipeline Function DescriptionClassIPipelines that represent a low hazard to human life and have alow economic impact in the event of failure. These pipelinesare not required to be functional immediately following anearthquake and can endure longer restoration times withoutimpact to the water utility. These pipelines primarily serveagricultural or irrigation usage, certain temporary facilities, orminor (non-water) storage facilities, which do not have asignificant role in local or regional economy.IIPipelines that provide water for typical use within the utilitywhere only a limited impact would be realized in the event offailure. These pipelines require less restoration time thanClass I pipelines to limit the impact to the surroundingcommunity. This category provides water for typical domesticuse within the system and includes all pipelines not identifiedin Class I, III, and IV.IIIPipelines that represent a higher criticality than the typicalpipelines within a utility. These pipelines deliver water tomany customers and may also result in significant social oreconomic impacts in the event of failure and outage. Pipelinerestoration times would need to be minimal following a majorevent.IVPipelines that provide water to essential facilities for postearthquake response, public health, and safety. Thesepipelines are intended to remain functional during and after adesigned earthquake without an immediate requiredrestoration time. These pipelines provide water for postearthquake firefighting and emergency support.– Japan Water Works Association (JWWA)Like the ORP, the Japan Water Works Association (JWWA) considers two levels of importanceranking for water facilities, those facilities with a high level of importance (Rank A) and otherfacilities (Rank B).17
Establish design earthquake WWSP seismic design parameters arebased on a Probabilistic Seismic HazardAnalysis (PSHA) [can also use aDeterministic Seismic Hazard Analysis(DSHA)] The WWSP has adopted the 2%probability of exceedance in 50 yearsfor its Design EarthquakeProbability of Exceedance (PE)50 percent PE in next 50 years10 percent PE in next 50 years2 percent PE in next 50 yearsRecurrence Interval 72 years 475 years 2,475 years18
Evaluate project specific seismic hazards
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Alaska 9.2 M Earthquake March 27, 1964, at 5:36 p.m."AlaskaQuake-FourthAve" by U.S. Army - http://libraryphoto.cr.usgs.gov/
PLM 5.0 transitions into & out of rockSoil/pipeinteractionmodeling
Anchorage, Alaska November 30, 2018Southbound lanes near Mirror Lake23
Consistent approach to pipeline seismichazards & limit statesTable 6-1. Types of Seismic Hazards
Establish design standards and methodsDesign ConsiderationsThe characterization of pipe systems for the purposes of seismic design typically involvestwo classifications, segmented pipe and continuous pipe systems. These two classificationsare defined as follows (O’Rourke and Lui, 2014):Segmented Pipe. A pipeline with lower axial and rotational stiffness at the joints than therest of the pipeline. Ductile iron and cast iron pipe are examples of a segmented pipe.Continuous Pipe. A pipeline joined by connections that exhibit axial and rotationalstiffness comparable to the rest of the pipe. Welded pipe (i.e. with welded joints) and fusedpipe (i.e. with fused joints) are examples of a continuous pipe.25
Establish design standards and methodsPipe Design Performance StandardsTable 14-6. Ductile Iron Pipe Seismic Performance Classifications (from ISO Standard16134, 2006, Table t resistanceJoint deflection angleClassComponent PerformanceS-1 1% of L or moreS-2 0.5% to less than 1% of LS-3Less than 0.5% of LA3d kN or moreB1.5d kN to less than 3d kNC0.75d kN to less than 1.5d kNDLess than 0.75d kNM-1 15o or moreM-2 7.5o to less than 15oM-3Less than 7.5oL is the component length, in millimeters (mm)d is the nominal diameter of the pipe, in millimeters (mm)26
Design for seismic risk mitigationDuctile iron pipe is considered a segmented pipe. The design for risk mitigation withductile iron pipe primarily focuses on the performance characteristics of the joint as this iswhere the damage is usually found to occur. Singhal and Benavides (1983) state:“The most frequent and severe damage usually occurs at or near a pipeline joint.Most failures result from ground strains that develop axial or shear forces in thepipelines and at the joints.”27
Design for seismic risk mitigationLimit States for Ductile Iron PipeLimit states establish design thresholds to consider as part of seismic risk mitigation andachieving desired levels of service performance. The primary goal is to maintain pipelinepressure integrity and avoid loss of containment. For ductile iron pipe systems there arefew guidelines to follow related to limit states. Wham et al. (2018) proposed two limitstates based primarily on internal pressure integrity, quantified by leakage rates, associatedwith large deformation performance of ductile iron pipe joints. These include thefollowing: Limit State 1: Serviceability Limit State 2: Ultimate28
Design for seismic risk mitigationPerformance Categories for Ductile Iron Pipe:Category 1: Non-restrained joints. These include standard push-on joints not designed to providepull-out resistance.Category 2: Joints with gripper gaskets/gripping wedges. This category includes those restrainedjoint systems that rely on wedges that grip the pipe.Category 3: Joints with integral restraint bead and boltless locking segments. This category providesimproved performance due to integrated joint restraining mechanisms.Category 4: Joints specially designed for combined seismic performance. These joints provide thehighest level of seismic performance. By design they are intended to provide a high level of joint axialmovement, axial joint strength, and joint deflection/rotation, either individually or when used incombination with other joint systems.29
Select other discussion topics Testing to establish ductile iron pipeperformance characteristicsWham et al. (2018) suggest that “each component of a hazardresilient system (including couplings, valves, tees, etc.) can, andshould, be evaluated for seismic performance and qualifiedfor expected levels of ground movement.”30
Select other discussion topics Other considerations for risk mitigationThe in-depth analysis may show that even greater performancerequirements than those associated with the highest ISOcomponent performance levels may be required. Seismic policies Existing infrastructure31
Select other discussion topics Other design issuesDuctile iron pipe products can be used in a variety ofcombinations to achieve the desired system performance.Consult manufacturers for the performance characteristics ofspecific ductile iron pipe products.As one designs a portion of a water system, it is important torecognize that elements of the system that may behavedifferently than other portions of the system and can result in anunexpected outcome. These may be in the form ofdiscontinuities between elements of the system or whereportions of the system perform differently and act as anchors forthe system in the ground.32
Select other discussion topicsA final design consideration relates to creating redundant supplies to critical customersor working with them specifically to make sure adequate emergency response plans aredeveloped. This will help mitigate any shortfalls in supply if that is to be expected.Understanding a customer’s needs and critical demand requirements is in itself a stepforward towards achieving system resilience. InstallationWith fittings that allow axial movement, the common joint installation position is “at themid-point, which allows for both joint expansion and contraction” (Gaston andRatcliffe, 2016).All installations should be performed in accordance with AWWA standards and thespecific written recommendations of the manufacturers. Critical repair parts33
Thank you!Mike Britch, P.E., MPAEngineering & Construction ManagerWillamette Water Supply iablewater.orgwww.ourreliablewater.org34
Seismic design framework [Discussion focused on AWWA M41 Proposed Chapter] Seismic framework steps: 1. Identify service priorities 2. Establish level of service goals 3. Establish design earthquake 4. Evaluate project specific seismic hazards 5. Establish design standards and methods 6. Design for seismic risk mitigation AWWA M41 Chapter 14.
The Seismic Tables defined in Pages 5 & 6 are for a seismic factor of 1.0g and can be used to determine brace location, sizes, and anchorage of pipe/duct/conduit and trapeze supports. The development of a new seismic table is required for seismic factors other than 1.0g and must be reviewed by OSHPD prior to seismic bracing. For OSHPD,
Peterson, M.D., and others, 2008, United States National Seismic Hazard Maps ․ Frankel, A. and others, Documentation for the 2002 Update of the National Seismic Hazard Maps ․ Frankel, A. and others, 1996, National Seismic Hazard Maps Evaluation of the Seismic Zoninig Method ․ Cornell, C.A., 1968, Engineering seismic risk analysis
To develop the seismic hazard and seismic risk maps of Taungoo. In developing the seismic hazard maps, probabilistic seismic hazard assessment (PSHA) method is used. We developed the seismic hazard maps for 10% probability of exceedance in 50 years (475 years return period) and 2 % probability in 50 years (2475 years return period). The seisic
Seismic hazard parameters are estimated and mapped in macro level and micro level based on the study area. The process of estimating seismic hazard parameters is called seismic . maps of Indian Regions earlier, based on several approaches. This includes probabilistic seismic hazard macrozonation of Tamil Nadu by Menon et al. (2010), Seismic .
SC2493 Seismic Technical Guide, Light Fixture Hanger Wire Requirements SC2494 Seismic Technical Guide, Specialty and Decorative Ceilings SC2495 Seismic Technical Guide, Suspended Drywall Ceiling Construction SC2496 Seismic Technical Guide, Seismic Expansion joints SC2497 Seismic
the seismic design of dams. KEYWORDS: Dam Foundation, Probabilistic Seismic Hazard Maps, Seismic Design 1. INTRODUCTION To perform seismic design or seismic diagnosis, it is very important to evaluate the earthquake hazard predicted for a dam site in order to predict earthquake damage and propose disaster prevention measures. There are two .
wave propagation in underground rocks, known as a seismic event. The velocity of seismic wave propagation can be recorded and monitored by installing seismic sensors such as geophones underground. The seismic events are similar to earthquakes but on a much smaller scale. The strength of seismic events is measured on a scale of moment magnitude.
asset management Ralph Rayner Professor, Centre for the Analysis of Time Series, London School of Economics and Political Science A description of established techniques for deriving environmental criteria for the management of assets is presented, followed by a review of the principal issues surrounding the practical application of uncertain knowledge of the future climate. A case study of .
