Cover -- Copyright -- Contents -- Preface -- Executive Committee -- Session Chairs -- International Committee -- PART 1: Contracting Practices and Cost -- Are Alternative Delivery Methods and Private Financing Ways to Deliver Future Underground Projects in America? -- Design-Build Construction in Underground Construction: A Contractor's Perspective -- Having Difficulty Deciding on Procuring New, Refurbished or Remanufactured TBMs? -- Incentive-Based Project Delivery with Fixed Price Incentive Fee Contracts -- North American Tunneling Industry Firsts in the Midwest: The Blacksnake Creek Stormwater Separation Improvement Tunnel -- Progressive Design-Build-Is It Coming to a Project Near You? -- A Study in the Use of Design-Build for Tunnel Projects -- Tunnel Contracting Practice: One Owner's State of the Art -- PART 2: Design and Planning -- Crosstown Tunneling for Houston Surface Water Supply -- Design and Construction Procurement for the Amtrak Hudson Tunnel Project -- Liner Load Estimation for Soft Ground Pressure Balance TBM Shield Tunnel Projects -- TBM Utilization in Mixed Transitional Ground: The OCIT Experience in Akron, Ohio -- Times Square Shuttle Station Reconstruction -- PART 3: Design/Build Projects -- Controlling Risk of Tunneling Projects Implemented by Alternative Delivery Method -- DC Clean Rivers Project: We Built Miles of Tunnel…Now What? How to Get the CSOs into the Tunnels in an Urban Environment -- Design and Construction of Montreal Express Link Tunnels and Underground Stations -- Design and Construction of NBAQ4 Water Transfer Scheme -- Evolution of Tunnel Eyes Designs Based on Lessons Learned for the Regional Connector Project in Los Angeles -- LA Metro Regional Connector Transit Project: Successful Halfway-Through Completion. Permitting in a Design/Build Environment-The Challenges of 120 Years of a Design Bid Build Culture -- West Gate Tunnel Project-Evolution in Three Lane TBM Road Tunnel Design -- PART 4: Difficult Ground -- Breaking Through Tough Ground in the Himalayas: Nepal's First TBM -- Challenging Geology: Blacklick Creek Sanitary Interceptor Sewer Project in Columbus, OH -- Cutting New Ground: TBM Selection for Fort Wayne Utilities Tunnel Works Program -- Ground Freezing to Improve Unstable Silty Ground -- Neelum-Jhelum Hydroelectric Project: Design and Construction Challenges of Underground Works -- Removal of Large Concrete Obstruction on 96-Inch Pipe Ram Crossing of Highway 61, Neebing, Ontario -- Unexpected Underground Obstructions: Challenges and Lessons Learned from Angeli, the Regional Connector TBM -- PART 5: Drill and Blast -- Applying Lessons Learned and Taking on New Challenges at the Lake Mead Intake No. 3 Low Lake Level Pumping Station Project -- Comparison of Emulsion and Anfo Usage in the Horizontal Development Process at El Teniente -- Connecting the TARP Des Plaines Tunnel System to the McCook Reservoir -- Construction of the Luck Stone Inter-Quarry Tunnel, Leesburg Virginia -- Drill and Blast Construction of Shafts and Starter and Tail Tunnels for the 3RPORT CSO Project -- PART 6: Environment, Health, and Safety -- Commissioning of Tunnel Fire Life Safety Systems and Its Challenges -- A Comparison of Breathing Gasses Used Under Hyperbaric Conditions -- Conception and Construction of a Tailor-Made and Contractor‑Built Refuge Chamber for TBM and SEM Drives According to German Guidelines -- InSAR Monitoring of Subsidence Induced by Underground Mining Operations -- Minimizing Impacts to the Community and Commuters: Constructing the District of Columbia's Largest Tunnel Along a Major Urban Artery. Optimization of a Ventilation System by Using Flow Measurements and 3D CFD Simulations -- Transit Tunnel TBM Vibration Through Glacial Till -- PART 7: Future Projects -- Alexandria Renew Enterprises Is Now in the Tunnel Business -- DART D2 Subway Project Development -- Mountain Tunnel Improvements Project -- MWRA Metropolitan Boston Tunnel Redundancy Program Project Update -- Unique Design Challenges of the Central Bayside System Improvement Project Tunnel Connections and Shafts -- PART 8: Geotechnical Considerations -- Anacostia River Tunnel Project Groundwater Drawdown Effects from the Deep Well Depressurization System at the CSO-019 Drop Shaft -- Digging Deeper-Supplemental Geotechnical Site Investigation for Parallel Thimble Shoal Tunnel -- How to Quantify the Reliability of a Geological and Geotechnical Reference Model in Underground Projects -- Innovative Monitoring for Urban Tunneling -- Packer and Long-Term Aquifer Testing to Estimate Tunnel Inflows: A Case History for the Lower Meramec Tunnel, St. Louis, MO -- Underground Construction, Geology and Geotechnical Risk -- Use and Misuse of Geotechnical Baselines to Predict Soft Ground TBM Tool Wear -- Writing the GBR So the Contractor Can Understand It -- PART 9: Ground Support and Final Lining -- 7.93 m Open TBM Shotcrete System Improvement and Innovation Jilin Project, China -- Complex Tunnel Through the Abutment of the High-Risk Chimney Hollow Dam -- Design Diagrams for Fiber Reinforced Concrete Tunnel Linings -- Steel Fiber Segmental Linings for Mega TBMs -- PART 10: Grouting and Ground Modification -- Differences in Consolidation Grouting Practices Between Near Surface and Underground Applications -- Grouting a TBM Shotcrete Lining Under Challenging Conditions -- Grouting and Groundwater in the Greater Arncliffe Area, WestConnex New M5 Tunnels, Sydney, Australia. Quality Control of Secant Piles and Jet Grouting for the Ohio Canal Interceptor Tunnel -- PART 11: Hard Rock TBMs -- Rand Park Stormwater Diversion Tunnel-Planning and Designing to Address Stormwater Flooding for Downtown Keokuk, Iowa -- The Three Rivers Protection and Overflow Reduction Tunnel (3RPORT)-Decision-Making During Construction -- TBMs: Meeting the Challenge in Pakistan's Lower Himalayas -- Waterway Protection Tunnel: Louisville's Innovative Solution to Four Storage Basins -- PART 12: Large Span Tunnels and Caverns -- Construction Considerations for Garage Cote Vertu in Montreal -- First Large Diameter Hard Rock CSO Chamber in St. Louis -- Rock Load Estimation for Shallow Rock Caverns -- Use of Spray Applied Waterproofing on the Downtown Bellevue Tunnel Project -- PART 13: New and Innovative Technologies -- Artificial Intelligence Technique for Geomechanical Forecasting -- Evaluating Impact of Water Content on EPB Machine Performance Based on Laboratory Experiments -- The Expanding Capabilities of Microtunneling Demonstrated in Washington DC -- High-Speed 3D Tunnel Inspection -- Implementation of Automation and Digitization in Tunnel Waterproofing and Grouting Practices -- Sandwich Belt High Angle Conveyors Exclusively at Paris Metro Expansion-2019 -- SCMAGLEV-Fast and Innovative Mode of Transportation in the Northeast Corridor-Tunneling Challenges -- Smart Office: A Data-Driven Management Tool for Mechanized Tunneling Construction -- Tunnel Survey Control in Small Segmentally Lined Tunnels -- PART 14: Pressure Face TBM Case Histories -- Effectiveness of Risk Mitigation Strategies for Large Diameter One-Pass Tunnels in Mixed Ground from Ohio Canal Interceptor Tunnel Construction -- EPB Clogging Through Mixed Transitional Ground, Lessons Learned at the Ohio Canal Interceptor Tunnel, Akron, OH. Planning, Design and Construction of the Regional Connector Bored Tunnels-An EPB Tunneling Case History -- Preparation for Tunneling, Don River & -- Central Waterfront Coxwell Sanitary Bypass Tunnel Project in Toronto, ON -- Tunneling in Mixed Face Conditions: An Enduring Challenge for EPB TBM Excavation -- PART 15: Pressure Face TBM Technology -- Curved Microtunneling Alignments in the Design Toolbox -- Forrestfield Airport Link-Project Challenges and TBM Solution -- Interpretation of EPB TBM Graphical Data -- Mechanized Tunneling at High Pressure-More Than Just a Stronger Bulkhead -- Proposal of Some Cuttability Indexes for Evaluating the Performance of Mechanical Excavators Using Conical Picks -- Tuen Mun-Chek Lap Kok Link in Hong Kong-Innovative Technologies and Methodologies for an Outstanding Project -- PART 16: SEM/NATM -- Culvert Construction Under I‑89 in Vermont Using the Sequential Excavation Method -- Delivering Value Through the Innovative Contractor Engagement (ICE) Model at London Underground Bank Station Capacity Upgrade Project -- SEM-Single Shell Lining Application for the Brenner Base Tunnel -- SEM Cavern Construction in Downtown LA -- SEM Tunnel Herrschaftsbuck: A Geological Challenge in Germany's Southwest -- Shallow SEM Tunneling with Limited Clearance to Existing Structures: Design, Construction and Observations -- Soft Ground Tunnelling Techniques for Mine Access Development -- Steep Inclined SEM Excavation-Successful Execution Applying Drill and Blast -- PART 17: Shafts and Mining -- Construction of Combined Sewer Overflow 021 Diversion Facilities in the District of Columbia -- Design and Construction Considerations for Large Shafts in Hudson River Tunnel Project: Hoboken Shaft -- Design Challenges of Deep Underground Shafts -- Merry Christmas!-Emergency Repair of the PCI‑12A Interceptor Collapse in Macomb County Michigan. The Role of Mechanized Shaft Sinking in International Tunnelling Projects.