1 NAT 2004 NAT 2004 – Atlanta, GA Atlanta, GA SEM / NATM Design and Contracting Strategies SEM / NATM Design and Contracting Strategies SEM / NATM Design and SEM / NATM Design and Contracting Strategies Contracting Strategies Gerhard Urschitz, PE, Dr. G. Sauer Corporation Gerhard Urschitz, PE, Dr. G. Sauer Corporation Joseph Joseph Gildner Gildner, PE, Sound Transit, WA , PE, Sound Transit, WA NAT 2004 NAT 2004 – Atlanta, GA Atlanta, GA SEM / NATM Design and Contracting Strategies SEM / NATM Design and Contracting Strategies INTRODUCTION INTRODUCTION • History of NATM in the US History of NATM in the US • NATM Design Philosophy NATM Design Philosophy • NATM Toolbox Concept NATM Toolbox Concept • Procurement Strategy Procurement Strategy • Contractor Pre Contractor Pre-Qualification Qualification • Case Histories Case Histories • Conclusions Conclusions NAT 2004 NAT 2004 – Atlanta, GA Atlanta, GA SEM / NATM Design and Contracting Strategies SEM / NATM Design and Contracting Strategies SEM / NATM / SCL / ….. SEM / NATM / SCL / ….. A Method with many names: A Method with many names: • NATM NATM – New Austrian Tunneling Method New Austrian Tunneling Method • SEM SEM – Sequential Excavation Method Sequential Excavation Method • SCL SCL – Shotcrete Lining Method Shotcrete Lining Method • Shotcrete hotcrete Support upport Method ethod • Sequential equential Support upport Method ethod • Shotcrete hotcrete Method ethod • Observational bservational Method ethod • Observational bservational Tunneling unneling Method ethod For the Purpose of the Presentation: For the Purpose of the Presentation: NATM NATM NAT 2004 NAT 2004 – Atlanta, GA Atlanta, GA SEM / NATM Design and Contracting Strategies SEM / NATM Design and Contracting Strategies HISTORY OF NATM IN THE US HISTORY OF NATM IN THE US • Since the early 1980s approx. 20 projects Since the early 1980s approx. 20 projects complete complete • Introduced through Introduced through VECPs VECPs or competitive or competitive bidding (WMATA) bidding (WMATA) • Currently many under design Currently many under design (e.g. Boston, New York, Kentucky, San (e.g. Boston, New York, Kentucky, San Francisco, Seattle, …) Francisco, Seattle, …) NAT 2004 NAT 2004 – Atlanta, GA Atlanta, GA SEM / NATM Design and Contracting Strategies SEM / NATM Design and Contracting Strategies WHAT IS NATM? WHAT IS NATM? • Developed in Europe in the 1950s for rock tunnels Developed in Europe in the 1950s for rock tunnels • Adapted for soft ground since 1968 Adapted for soft ground since 1968 (Frankfurt, Germany) (Frankfurt, Germany) NAT 2004 NAT 2004 – Atlanta, GA Atlanta, GA SEM / NATM Design and Contracting Strategies SEM / NATM Design and Contracting Strategies COST DEVELOPMENT COST DEVELOPMENT Subway Construction Munich (Running Tunnels)
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NAT 2004 NAT 2004 –– Atlanta, GAAtlanta, GASEM / NATM Design and Contracting StrategiesSEM / NATM Design and Contracting Strategies
SEM / NATM Design and SEM / NATM Design and Contracting StrategiesContracting Strategies
Gerhard Urschitz, PE, Dr. G. Sauer CorporationGerhard Urschitz, PE, Dr. G. Sauer CorporationJoseph Joseph GildnerGildner, PE, Sound Transit, WA, PE, Sound Transit, WA
NAT 2004 NAT 2004 –– Atlanta, GAAtlanta, GASEM / NATM Design and Contracting StrategiesSEM / NATM Design and Contracting Strategies
INTRODUCTIONINTRODUCTION
•• History of NATM in the USHistory of NATM in the US
For the Purpose of the Presentation: For the Purpose of the Presentation: NATMNATMNAT 2004 NAT 2004 –– Atlanta, GAAtlanta, GASEM / NATM Design and Contracting StrategiesSEM / NATM Design and Contracting Strategies
HISTORY OF NATM IN THE USHISTORY OF NATM IN THE US
•• Since the early 1980s approx. 20 projects Since the early 1980s approx. 20 projects completecomplete
•• Introduced through Introduced through VECPsVECPs or competitive or competitive bidding (WMATA) bidding (WMATA)
•• Currently many under designCurrently many under design(e.g. Boston, New York, Kentucky, San (e.g. Boston, New York, Kentucky, San Francisco, Seattle, …)Francisco, Seattle, …)
NAT 2004 NAT 2004 –– Atlanta, GAAtlanta, GASEM / NATM Design and Contracting StrategiesSEM / NATM Design and Contracting Strategies
WHAT IS NATM?WHAT IS NATM?
•• Developed in Europe in the 1950s for rock tunnelsDeveloped in Europe in the 1950s for rock tunnels•• Adapted for soft ground since 1968 Adapted for soft ground since 1968
(Frankfurt, Germany)(Frankfurt, Germany)
NAT 2004 NAT 2004 –– Atlanta, GAAtlanta, GASEM / NATM Design and Contracting StrategiesSEM / NATM Design and Contracting Strategies
COST DEVELOPMENTCOST DEVELOPMENT
Subway Construction Munich (Running Tunnels)
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NAT 2004 NAT 2004 –– Atlanta, GAAtlanta, GASEM / NATM Design and Contracting StrategiesSEM / NATM Design and Contracting Strategies
COST COMPARISONCOST COMPARISON
67.5 %65.4 %44.5 %40.8 %- considering a 75% pit covering
93.0 %97.2 %63.5 %50.0 %- regardless of pit covering
Bid Price Relationship for Metropolitan Railroads in Bochum
NAT 2004 NAT 2004 –– Atlanta, GAAtlanta, GASEM / NATM Design and Contracting StrategiesSEM / NATM Design and Contracting Strategies
NATM ADAPTED FOR THE USNATM ADAPTED FOR THE US
•• Robust Design Robust Design instead ofinstead ofDecisions in the FieldDecisions in the Field
•• Compromising the Concept of theCompromising the Concept of the Observational Observational MethodMethod
•• Prescriptive DesignPrescriptive Design•• Design Peer ReviewsDesign Peer Reviews•• PrePre--Qualification ProcessQualification Process•• Requirements for CM and SupervisionRequirements for CM and Supervision
(Designers involved during construction)(Designers involved during construction)•• Approval of Proposed Means and MethodsApproval of Proposed Means and Methods•• Adjustment of Contingency StrategiesAdjustment of Contingency Strategies
NAT 2004 NAT 2004 –– Atlanta, GAAtlanta, GASEM / NATM Design and Contracting StrategiesSEM / NATM Design and Contracting Strategies
NATM DESIGN PHILOSOPHYNATM DESIGN PHILOSOPHY
General Principle:General Principle:“Mobilizing the surrounding ground by “Mobilizing the surrounding ground by developing the maximum selfdeveloping the maximum self--supporting supporting capacity of the rock or soil” capacity of the rock or soil”
DevelopDevelop-- Excavation SequencesExcavation Sequences-- PrePre--supportsupport-- Face SupportFace Support-- Ground Improvement depending onGround Improvement depending on
GROUND CONDITIONSGROUND CONDITIONS and and SIZESIZE of STRUCTUREof STRUCTURE
NAT 2004 NAT 2004 –– Atlanta, GAAtlanta, GASEM / NATM Design and Contracting StrategiesSEM / NATM Design and Contracting Strategies
““Greater skill is needed to avoid (minimize) Greater skill is needed to avoid (minimize) ground load than to resist it” ground load than to resist it” ((RzihaRziha, 1872), 1872)
Stronger or stiffer lining is not better!Stronger or stiffer lining is not better!
NATM DESIGN PHILOSOPHYNATM DESIGN PHILOSOPHY
NAT 2004 NAT 2004 –– Atlanta, GAAtlanta, GASEM / NATM Design and Contracting StrategiesSEM / NATM Design and Contracting Strategies
NATM DESIGN PHILOSOPHYNATM DESIGN PHILOSOPHY
NATM DesignNATM Design
E&S ClassesE&S Classes NATM ToolboxNATM Toolbox
Hard Rock Soft Ground
Class 1: …..Class 2: …..Class 3: …..
NAT 2004 NAT 2004 –– Atlanta, GAAtlanta, GASEM / NATM Design and Contracting StrategiesSEM / NATM Design and Contracting Strategies
NATM TOOLBOX CONCEPTNATM TOOLBOX CONCEPT
•• NATM Tunneling in Soft GroundNATM Tunneling in Soft Ground•• Varying or Complex GroundVarying or Complex Ground•• Multiple or Selected Multiple or Selected
-- PrePre--supportsupport-- Ground ImprovementGround Improvement-- Other Support ElementsOther Support Elements
•• In Addition to Standard Support MeasuresIn Addition to Standard Support Measures(Flashcrete, Shotcrete Lining, Dewatering)(Flashcrete, Shotcrete Lining, Dewatering)
•• Paid with Unit PricesPaid with Unit Prices
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NAT 2004 NAT 2004 –– Atlanta, GAAtlanta, GASEM / NATM Design and Contracting StrategiesSEM / NATM Design and Contracting Strategies
NATM TOOLBOX CONCEPTNATM TOOLBOX CONCEPT
NATM Toolbox ItemsNATM Toolbox Items
NAT 2004 NAT 2004 –– Atlanta, GAAtlanta, GASEM / NATM Design and Contracting StrategiesSEM / NATM Design and Contracting Strategies
NATM TOOLBOX CONCEPTNATM TOOLBOX CONCEPT
Geometry and Sequence:Geometry and Sequence:•• Top Heading/Bench/InvertTop Heading/Bench/Invert•• Sidewall DriftSidewall Drift•• Dual Sidewall DriftDual Sidewall Drift
Sidewall Drift Improvements:Sidewall Drift Improvements:•• Foundation for SidewallFoundation for Sidewall•• Increase Bearing Capacity of SWIncrease Bearing Capacity of SW
NAT 2004 NAT 2004 –– Atlanta, GAAtlanta, GASEM / NATM Design and Contracting StrategiesSEM / NATM Design and Contracting Strategies
NATM TOOLBOX CONCEPTNATM TOOLBOX CONCEPT
•• Application CriteriaApplication Criteria•• Estimated QuantitiesEstimated Quantities•• Standby and Standby and
InstallationInstallation•• “… as approved or “… as approved or
directed …”directed …”
NAT 2004 NAT 2004 –– Atlanta, GAAtlanta, GASEM / NATM Design and Contracting StrategiesSEM / NATM Design and Contracting Strategies
•• Surface, Ground, InSurface, Ground, In--Tunnel MonitoringTunnel Monitoring•• Purpose: determine loosening zones and Purpose: determine loosening zones and
movements of ground and structuresmovements of ground and structures•• Reading frequency and reporting to make Reading frequency and reporting to make
decisions and verify assumptionsdecisions and verify assumptions
•• Who is reading?Who is reading?
NATM DESIGN PHILOSOPHYNATM DESIGN PHILOSOPHYInstrumentation and MonitoringInstrumentation and Monitoring
Toolbox)Toolbox)•• Support (Flashcrete, Lattice Girders, Support (Flashcrete, Lattice Girders,
Shotcrete)Shotcrete)•• WaterproofingWaterproofing•• Final Lining (Thickness and Final Lining (Thickness and
Reinforcement)Reinforcement)
Prescriptive vs. Performance DesignPrescriptive vs. Performance Design
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NAT 2004 NAT 2004 –– Atlanta, GAAtlanta, GASEM / NATM Design and Contracting StrategiesSEM / NATM Design and Contracting Strategies
Why do we prescribe?Why do we prescribe?•• Excavation Sequence (Type of Drift Excavation)Excavation Sequence (Type of Drift Excavation)•• Advance LengthAdvance Length•• PrePre--support (Spiling, Barrel Vault, NATM Toolbox)support (Spiling, Barrel Vault, NATM Toolbox)
Complex Geologic Conditions, Large Complex Geologic Conditions, Large Structures, Experience, Stability, SafetyStructures, Experience, Stability, Safety
•• Support (Flashcrete, Lattice Girders, Shotcrete)Support (Flashcrete, Lattice Girders, Shotcrete)Result of Complex AnalysesResult of Complex Analyses
•• WaterproofingWaterproofingToo Many Negative Case HistoriesToo Many Negative Case Histories
•• Final Lining (Thickness and Reinforcement)Final Lining (Thickness and Reinforcement)Analysis, receive the expected ProductAnalysis, receive the expected Product
NATM DESIGN PHILOSOPHYNATM DESIGN PHILOSOPHY
NAT 2004 NAT 2004 –– Atlanta, GAAtlanta, GASEM / NATM Design and Contracting StrategiesSEM / NATM Design and Contracting Strategies
Where is the Flexibility for the Contractor?Where is the Flexibility for the Contractor?
•• Construction Sequence Construction Sequence •• Provide Minimum and Maximum Distances Provide Minimum and Maximum Distances
between Headings between Headings •• NATM ToolboxNATM Toolbox•• Equipment not SpecifiedEquipment not Specified•• Dry / Wet ShotcreteDry / Wet Shotcrete•• Field Decisions with Experienced CM TeamField Decisions with Experienced CM Team
NATM DESIGN PHILOSOPHYNATM DESIGN PHILOSOPHYPrescriptive vs. Performance DesignPrescriptive vs. Performance Design
NAT 2004 NAT 2004 –– Atlanta, GAAtlanta, GASEM / NATM Design and Contracting StrategiesSEM / NATM Design and Contracting Strategies
PROCUREMENT STRATEGYPROCUREMENT STRATEGY
Contracting Options:Contracting Options:
•• DesignDesign--BidBid--BuildBuild
•• DesignDesign--BuildBuild
•• Cost plus FeeCost plus Fee
Balance of Risk and ControlBalance of Risk and Control
NAT 2004 NAT 2004 –– Atlanta, GAAtlanta, GASEM / NATM Design and Contracting StrategiesSEM / NATM Design and Contracting Strategies
DESIGNDESIGN--BUILDBUILD
Motivation to choose DB:Motivation to choose DB:
•• Risk Allocation:Risk Allocation: TransferTransfer•• Efficiency:Efficiency: Performance Design based Performance Design based
on on availableavailable InformationInformation
Ownership of the GroundOwnership of the Ground
Requires strong (NATM) CM and Requires strong (NATM) CM and experienced contractorexperienced contractor
NAT 2004 NAT 2004 –– Atlanta, GAAtlanta, GASEM / NATM Design and Contracting StrategiesSEM / NATM Design and Contracting Strategies
COST PLUS FEECOST PLUS FEE
•• Very Challenging EnvironmentVery Challenging Environment•• High Degree of Risk and ResponsibilityHigh Degree of Risk and Responsibility
Example: Exchange Place Station, NJExample: Exchange Place Station, NJ
NAT 2004 NAT 2004 –– Atlanta, GAAtlanta, GASEM / NATM Design and Contracting StrategiesSEM / NATM Design and Contracting Strategies
NAT 2004 NAT 2004 –– Atlanta, GAAtlanta, GASEM / NATM Design and Contracting StrategiesSEM / NATM Design and Contracting Strategies
PROJECTPROJECT
Beacon Hill StationBeacon Hill StationSeattle, WASeattle, WA
NAT 2004 NAT 2004 –– Atlanta, GAAtlanta, GASEM / NATM Design and Contracting StrategiesSEM / NATM Design and Contracting Strategies
PROCUREMENT STRATEGYPROCUREMENT STRATEGY
Conclusions:Conclusions:
•• NATM is still a new Technology in the USNATM is still a new Technology in the US•• Cost effective / Alternative TechnologyCost effective / Alternative Technology•• No “one fits all” Solution No “one fits all” Solution •• Designers to be involved through ConstructionDesigners to be involved through Construction•• Contractors / Unions to gain ExperienceContractors / Unions to gain Experience•• Better Marketing / more Discussions requiredBetter Marketing / more Discussions required
For an exciting future with an innovative technology!For an exciting future with an innovative technology!
NAT 2004 NAT 2004 –– Atlanta, GAAtlanta, GASEM / NATM Design and Contracting StrategiesSEM / NATM Design and Contracting Strategies
