HIGHWAY DESIGN MANUAL CHAPTER 9 - SOILS, WALLS, AND FOUNDATIONS Revision 75 September 15, 2013 This page is intentionally left blank. CHAPTER 9 SOILS, WALLS, AND FOUNDATIONS Contents Page 9.1 INTRODUCTION................................................................................................................9-1 9.2 GEOTECHNICAL INVESTIGATIONS ................................................................................9-2 9.2.1 Geotechnical Reports ...............................................................................................9-2 9.2.2 Subsurface Explorations ..........................................................................................9-7 9.3 SOIL AND FOUNDATION CONSIDERATIONS .............................................................. 9-18 9.3.1 Alignment ............................................................................................................... 9-19 9.3.2 Resurfacing, Restoration, and Rehabilitation (3R) .................................................. 9-20 9.3.3 Widening ................................................................................................................ 9-21 9.3.4 Settlement .............................................................................................................. 9-22 9.3.5 Stability .................................................................................................................. 9-26 9.3.6 Embankment Foundation ....................................................................................... 9-29 9.3.7 Geotechnical Design Guidance for Stormwater Management and Erosion and Sediment Control ................................................................................ 9-32 9.3.8 Underdrains and Edge Drains ................................................................................ 9-45 9.3.9 Cut Slopes ............................................................................................................. 9-51 9.3.10 Frost Heaves and Boulder Heaves ....................................................................... 9-59 9.3.11 Rock Excavation .................................................................................................. 9-60 9.3.12 Excavation, Excavation Protection and Support ................................................... 9-62 9.3.13 Design of Spoil Sites ............................................................................................ 9-63 9.3.14 Optional Borrow Areas ......................................................................................... 9-65 9.3.15 Geotextiles ........................................................................................................... 9-68 9.3.16 Controlled Low Strength Material (CLSM) ............................................................ 9-73 9.3.17 Lightweight Concrete Fill .................................................................................... 9-74a 9.4 RETAINING WALLS AND REINFORCED SOIL SLOPES AND WALLS ........................ 9-75 9.4.1 Definitions .............................................................................................................. 9-75 9.4.2 Wall Types ............................................................................................................. 9-77 9.4.2.1 Externally Stabilized Cut Structures..................................................................... 9-77 9.4.2.2 Externally Stabilized Fill Structures ..................................................................... 9-81 9.4.2.3 Internally Stabilized Fill Structures ....................................................................... 9-85 9.4.2.4 Internally Stabilized Cut Structures ...................................................................... 9-93 9.4.2.5 Miscellaneous ..................................................................................................... 9-94 9.4.3 Proprietary Retaining Wall Systems ....................................................................... 9-95 9.4.4 Wall Selection Process ........................................................................................... 9-95 9.4.5 Wall Design & Detailing .......................................................................................... 9-95 9.4.6 Aesthetic Treatments ........................................................................................... 9-112 9.4.7 Sole Source ......................................................................................................... 9-114 9/15/13 CHAPTER 9 SOILS, WALLS, AND FOUNDATIONS Contents Page 9.5 DEEP FOUNDATIONS .................................................................................................. 9-115 9.5.1 Drilled Shafts ........................................................................................................ 9-115 9.5.2 Driven Piles .......................................................................................................... 9-118 9.5.3 Micropiles ............................................................................................................. 9-120 9. 6 BUILDING CONDITION SURVEY AND VIBRATION MONITORING (NONBLASTING)........... 9-123 9.6.1 General ............................................................................................................ 9-123 9.6.2 Design Considerations ..................................................................................... 9-124 9.6.2.1 Adjacent Sensitive Structures .......................................................................... 9-125 9.6.2.2 Consultation ..................................................................................................... 9-127 9.6.2.3 Action .............................................................................................................. 9-128 9. 7 TRENCHLESS INSTALLATION OF CASING .............................................................. 9-129 9.7.1 General ............................................................................................................ 9-129 9.7.2 Definitions ........................................................................................................ 9-129 9.7.3 Casing, Length, Type, and Size ....................................................................... 9-132 9.7.4 Design Development........................................................................................ 9-133 9.7.5 Submittal Process ............................................................................................ 9-137 9.7.6 Designer Guidance .......................................................................................... 9-138 9. 8 CONTRACT INFORMATION ........................................................................................ 9-140 9.8.1 Earthwork Summary Sheet .............................................................................. 9-140 9.8.2 Specifications .................................................................................................. 9-141 9.8.3 Proposal .......................................................................................................... 9-142 9.8.4 Plans .............................................................................................................. 9-143 9.9 REFERENCES .............................................................................................................. 9-146 APPENDIX 9A - PROPRIETARY WALL SYSTEM EVALUATION PROCESS ..................... 9A-1 9A.1 Procedure Overview .............................................................................................. 9A-1 9A.2 Definitions and Roles ............................................................................................. 9A-1 9A.3 Procedural Guidelines ............................................................................................ 9A-3 9A.4 Steps in the PreApproval Process ......................................................................... 9A-4 9A.5 Related Official Issuances...................................................................................... 9A-6 Attachment 1 Instructions for Preparation of the Application Package ................................... 9A-7 APPENDIX 9B - PROJECT CHECKLIST FOR DETERMINING IF SUBSURFACE EXPLORATIONS ARE REQUIRED ........................................................ 9B-1 APPENDIX 9C - SUBJECT INDEX ....................................................................................... 9C-1 9/15/13 CHAPTER 9 SOILS, WALLS, AND FOUNDATIONS LIST OF FIGURES Figure Title Page 9.2-1 a Drilling in Roadway .....................................................................................9-7 b Drilling in a Parking Lot ...............................................................................9-7 c Drilling on Steep Terrain ..............................................................................9-8 d Drilling on Ice ..............................................................................................9-8 e Drilling with All-Terrain Vehicle (ATV) Drill Rig ............................................9-8 f Drilling on Soft Soils ....................................................................................9-8 g Drilling off a Barge .......................................................................................9-8 9.2-2 a Split Spoon Sampler ................................................................................. 9-10 b Split Spoon Sampler Opened (Split) .........................................................