Knik Arm Crossing Engineering Feasibility and Cost Estimate Update State Project No. 56047 Volume 2 Technology Update Prepared for: Alaska Department of Transportation and Public Facilities Prepared by: Parsons Brinckerhoff HDR Alaska, Inc. In affiliation with: Fugro West, Inc. ASCG, Inc. Black-Smith & Richards Shannon & Wilson, Inc. TY Lin International EKM Engineering, Inc. (sub to TY Lin International) Word Wrangling, Inc. January 31, 2003 Knik Arm Crossing Engineering Feasibility and Cost Estimate Update State Project No. 56047 Volume 2 Technology Update Prepared for: Alaska Department of Transportation and Public Facilities Prepared by: Parsons Brinckerhoff/HDR Alaska, Inc. In affiliation with: Fugro West, Inc. ASCG, Inc. Black-Smith & Richards Shannon & Wilson, Inc. TY Lin International EKM Engineering, Inc. (sub to TY Lin International) Word Wrangling January 31, 2003 Volume 2: Technology Update 1.0 INTRODUCTION ............................................................................................................... 1-1 1.1 SOUTH APPROACH............................................................................................... 1-1 1.2 KNIK ARM CROSSING.......................................................................................... 1-2 1.3 NORTH APPROACH .............................................................................................. 1-2 2.0 GEOTECHNICAL AND FOUNDATION UPDATE......................................................... 2-1 2.1 SUMMARY.............................................................................................................. 2-1 2.2 GEOTECHNICAL AND FOUNDATION ANALYSIS .......................................... 2-2 2.2.1 Bridge Crossing ............................................................................................. 2-2 2.2.2 Ship Creek Crossing Soils.............................................................................. 2-3 2.2.3 Government Hill Soils ................................................................................... 2-4 2.3 SEISMIC DESIGN UPDATE .................................................................................. 2-4 2.3.1 Previous Seismic Analyses ............................................................................ 2-4 2.3.2 Recent Regional Seismicity ........................................................................... 2-5 2.4 BRIDGE FOUNDATION CONSIDERATIONS..................................................... 2-5 2.4.1 Piers Description............................................................................................ 2-5 2.4.1.1 Subsurface Conditions ........................................................................ 2-6 2.4.2 Pile Size and Hammers Considered ............................................................... 2-8 2.4.3 Methodology.................................................................................................. 2-8 2.5 CONCLUSIONS ...................................................................................................... 2-9 2.5.1 Design Development Considerations........................................................... 2-14 2.6 CONSTRUCTION CONSIDERATIONS.............................................................. 2-14 2.7 ABUTMENT AND HIGHWAY EMBANKMENT CONSIDERATIONS ........... 2-15 2.7.1 Bridge Over Ship Creek............................................................................... 2-15 2.7.2 Government Hill Landslide.......................................................................... 2-16 2.7.3 Cut-and Cover Tunnel through Government Hill ........................................ 2-16 2.7.4 Port of Anchorage........................................................................................ 2-17 2.7.5 Shoreline Embankment................................................................................ 2-17 2.7.6 Abutment Bluffs........................................................................................... 2-18 2.7.7 Pavement Section......................................................................................... 2-19 2.8 CLOSURE .............................................................................................................. 2-20 2.8.1 Use of Design Information........................................................................... 2-20 2.8.2 Potential Variation in Subsurface Conditions.............................................. 2-20 3.0 STRUCTURE TYPE UPDATE .......................................................................................... 3-1 3.1 SUMMARY.............................................................................................................. 3-1 3.2 ANALYSIS............................................................................................................... 3-1 3.2.1 Hybrid Alignment .......................................................................................... 3-1 3.2.2 Superstructure ................................................................................................ 3-1 3.2.2.1 Material ............................................................................................... 3-3 3.2.2.2 Railroad Options ................................................................................. 3-3 3.2.2.3 Road-Only Option............................................................................... 3-6 3.2.2.4 Construction........................................................................................ 3-8 3.2.3 Piers ............................................................................................................. 3-12 3.2.4 Pile Caps ...................................................................................................... 3-13 3.2.5 Piles.............................................................................................................. 3-17 3.2.6 Loads............................................................................................................ 3-18 3.2.6.1 Live Load.......................................................................................... 3-18 3.2.6.2 Earthquake ........................................................................................ 3-19 Page i Volume 2: Technology Update 3.2.6.3 Ice...................................................................................................... 3-23 3.2.7 Knik Arm Oceanographic Conditions.......................................................... 3-24 3.2.7.1 Tides.................................................................................................. 3-24 3.2.7.2 Currents............................................................................................. 3-24 3.2.7.3 Scour ................................................................................................. 3-25 3.2.7.4 Waves................................................................................................ 3-26 3.2.8 Feasibility and Cost...................................................................................... 3-26 3.2.8.1 Comparable Projects ......................................................................... 3-26 3.2.8.2 Cost Breakdown................................................................................ 3-28 3.2.9 Conclusion ................................................................................................... 3-30 4.0 TUNNEL TECHNOLOGY AND ALTERNATIVES......................................................... 4-1 4.1 SUMMARY.............................................................................................................. 4-1 4.2 TUNNEL TECHNOLOGY UPDATE AND ASSUMPTION ................................. 4-1 4.2.1 Immersed Tube Tunnels................................................................................. 4-1 4.2.2 Soft-Ground Bored Tunnels........................................................................... 4-3 4.2.3 Tunnel Bores in Coarse-Grained Soils........................................................... 4-6 4.2.4 Tunneling Bores in Fine- and Coarse-Grained Soils ..................................... 4-7 4.3 TUNNEL BORING MACHINES ............................................................................ 4-7 4.3.1 Slurry-Pressure Balance Machines ................................................................ 4-7 4.3.2 Earth-Pressure Balance Machine ................................................................... 4-8 4.3.3 Cutter Head Wear .......................................................................................... 4-9 4.3.4 Tunnel Support............................................................................................... 4-9 4.3.5 Tunnel Tour ................................................................................................. 4-10 4.3.5.1 Tunnel Tour Findings........................................................................ 4-10 4.4 ANALYSIS............................................................................................................. 4-11 4.4.1 Crossing Location and Geologic Setting ..................................................... 4-11 4.4.2 Design Criteria............................................................................................. 4-13 4.4.2.1 Fire and Life Safety Standards and Codes ........................................ 4-13 4.4.2.2 Lighting Standards and Codes .......................................................... 4-13 4.4.2.3 Ventilation and Emergency Egress Standards and Codes................. 4-14 4.4.3