GGUUIIDDEELLIINNEESS FFOORR MMIINNEE HHAAUULL RROOAADD DDEESSIIGGNN Dwayne D. Tannant & Bruce Regensburg 2001 Guidelines for Mine Haul Road Design Table of Contents 1 SURVEY OF HAUL TRUCKS & ROADS FOR SURFACE MINES ............................... 1 1.1 Introduction ..................................................................................................................... 1 1.2 Haul Trucks and Construction/Maintenance Equipment ................................................. 1 1.3 Haul Road Length ............................................................................................................ 3 1.4 Haul Road Geometry ....................................................................................................... 4 1.5 Haul Road Construction Materials .................................................................................. 6 1.6 Symptoms and Causes of Haul Road Deterioration ........................................................ 6 1.7 Haul Road Maintenance .................................................................................................. 7 1.8 Evolution of Haul Road Design at Syncrude ................................................................... 8 1.8.1 Layer Thickness .................................................................................................................. 9 1.8.2 Haul Road Geometry .......................................................................................................... 9 1.8.3 Construction Techniques .................................................................................................. 10 1.9 Summary ........................................................................................................................ 11 2 HAUL ROAD PLANNING AND ALIGNMENT ............................................................... 12 2.1 General .......................................................................................................................... 12 2.2 Key Road Planning and Alignment Factors .................................................................. 12 2.3 Haul Truck Stopping Distance ...................................................................................... 13 2.4 Sight Distance and Vertical Curves ............................................................................... 15 2.5 Road Width .................................................................................................................... 16 2.6 Curves and Switchbacks ................................................................................................ 18 2.7 Super-Elevation ............................................................................................................. 20 2.7.1 Super-Elevation Runout .................................................................................................... 22 2.8 Optimal Grades .............................................................................................................. 23 2.8.1 Maximum Sustained Grade .............................................................................................. 26 2.8.2 Runaway Provisions ......................................................................................................... 26 2.9 Combination of Horizontal and Vertical Alignment ..................................................... 27 2.10 Safety Berms and Ditches .............................................................................................. 27 3 DESIGN OF HAUL ROAD CROSS-SECTION ................................................................ 28 3.1 Introduction ................................................................................................................... 28 3.2 Design Based on CBR ................................................................................................... 30 3.2.1 Modifications to CBR Design Method ............................................................................. 32 3.3 Design Based on Critical Strain and Resilient Modulus ................................................ 34 3.3.1 Critical Strain Limit .......................................................................................................... 36 3.3.2 Design Procedure .............................................................................................................. 37 3.4 Comparison of the Two Methods .................................................................................. 38 3.5 Correlation Between the Vertical Strain and Surface Deflection .................................. 40 3.6 Summary ........................................................................................................................ 42 4 ROAD SURFACE ................................................................................................................. 43 4.1 Introduction ................................................................................................................... 43 4.2 Roughness ...................................................................................................................... 43 4.3 Traction .......................................................................................................................... 44 4.4 Rolling Resistance ......................................................................................................... 45 4.4.1 Measuring Rolling Resistance .......................................................................................... 47 4.4.2 Typical Rolling Resistance Values ................................................................................... 48 4.4.3 Economic Impact of Rolling Resistance ........................................................................... 50 4.5 Haul Road Trafficability and Cycle Time ..................................................................... 51 4.6 Road Maintenance and Repair ....................................................................................... 52 4.7 Drainage Requirements ................................................................................................. 53 4.8 Dust Suppressants .......................................................................................................... 54 ii Guidelines for Mine Haul Road Design 5 ROAD CONSTRUCTION MATERIALS .......................................................................... 57 5.1 Surface Layer Materials ................................................................................................. 57 5.1.1 Compacted Gravel and Crushed Rock .............................................................................. 58 5.1.2 Asphaltic Concrete ............................................................................................................ 61 5.1.3 Roller Compacted Concrete .............................................................................................. 62 5.2 Materials for Base and Sub-Base Layers ....................................................................... 63 5.2.1 Material Properties ............................................................................................................ 63 5.2.2 Fly Ash ............................................................................................................................. 65 5.3 Compaction Requirements ............................................................................................ 66 6 HAUL ROAD ECONOMICS ............................................................................................... 68 6.1 Introduction ................................................................................................................... 68 6.2 Costs Associated with Road Building ........................................................................... 68 6.2.1 Pre-Road Construction Preparation .................................................................................. 68 6.2.2 Road Construction Costs .................................................................................................. 69 6.2.3 Road Removal Costs ......................................................................................................... 69 6.2.4 Fleet Productivity .............................................................................................................. 69 6.3 Road Maintenance ......................................................................................................... 70 6.4 Extra Fleet Operating and Maintenance Costs .............................................................. 70 6.5 Other Considerations ..................................................................................................... 71 6.5.1 Climate.............................................................................................................................. 71 6.5.2 Application of Larger Trucks ........................................................................................... 71 6.6 Comparison of Temporary and Semi-Permanent Roads ............................................... 72 6.6.1 Temporary Road ............................................................................................................... 72 6.6.2 Semi-Permanent Road ...................................................................................................... 73 6.6.3 Conclusion ........................................................................................................................ 73 6.7 Example of Full Life Cycle