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Selection, maintenance, and relations of various parameters for off-highway hauling tires
Published in Tad S. Golosinski, Val Srajer, Off-Highway Haulage in Surface Mines, 1989
Haul roads plays a vital role in selecting a tire. Good haul roads results in reduced fuel consumption, higher vehicle speed, longer tire life, better operator comfort, better efficiency, and safer working conditions. Greater attention is therefore needed in designing and maintaining proper haul roads. The characteristics of good haul roads are: good surface, adequate drainage, good sight distance for safety, ample passing width, lowest possible adverse grade, long radius and super elevated curves. Haul road surface material determines the rolling resistance and tractive coefficient, which in turn affects vehicle speed and gradeability. Asphaltic concrete, crushed stone or gravel and established earth are the most practical surface materials for haul road construction. It is advisable to have a longer travel distance with less adverse grade than a short travel distance with steep grades. For each addition of 1% grade the vehicle has to overcome 10 kg / tonne of gross weight. Curves also affects the tire life. When negotiating curves the lateral forces in tire generates higher heat, which contributes to ply separation and high tire wear. To eliminate these lateral forces, super elevation of curves is recommended. The amount of super elevation depends on radius of the curve and the speed at which the vehicle is intended to move.
Introduction to mine haul roads
Published in Thompson Roger J., Peroni Rodrigo, Visser Alex T., Mining Haul Roads, 2019
Thompson Roger J., Peroni Rodrigo, Visser Alex T.
In the case of surface mining, economy of scale and the increase in haul truck payload, as shown in Figure 1.2, have so far seen the RDT ultra-class truck (> 220 t payload, > 380 t GVM) population rise significantly (Gilewicz, 2006). With this increasing size, haul road performance can be compromised, resulting in excessive total road-user costs; often seen directly as an increase in cost per ton hauled, but also indirectly as reduced production rates and vehicle and component service life. Especially with the larger haul trucks now predominant in surface mining, it is advantageous to consider the haul road as an asset, similar to the vehicles that use the road.
Open pit mine design
Published in Martin Lloyd Smith, Geologic and Mine Modelling using Techbase and Lynx, 2020
The layout of the haul road has to balance several objectives while remaining within the road design’s criteria: minimizing both the distance and tonnage hauled, minimizing the loss in reserves or increase in stripping ratio and providing a profile which limits wear and tear on trucks.
Multi-body dynamic modelling of ultra-large dump truck-haul road interactions towards haul road design integrity
Published in International Journal of Mining, Reclamation and Environment, 2020
Bruno Ayaga Kansake, Samuel Frimpong, Danish Ali
The safety, productivity and equipment longevity of mines employing ultra-large trucks (≥ 220 tons capacity) are reliant on well-designed, constructed and maintained haul roads [9]. Truck component and tire wear and damage increase significantly due to poor haul roads. Efficient haul road design and maintenance minimise these problems and ensure efficient haulage operations. Efficient haul road design comprises designing roads with adequate structural integrity to withstand the dynamic loads from trucks. Building good haul roads usually has a high initial cost, but the long-term benefits of efficient haulage, minimal road maintenance, improved productivity, safety, and tire life, and operator and machine health, outweigh this cost [6]. Maintaining poor haul roads can ultimately cost about 10 times the cost of building good haul roads [10] over the mine life.
Analytical modelling of dump truck tire dynamic response to haul road surface excitations
Published in International Journal of Mining, Reclamation and Environment, 2020
Bruno Ayaga Kansake, Samuel Frimpong
The random road profile generated from the Simulink model is shown in Figure 4. This profile shows haul road surface roughness ranging from −53.3 mm to 52 mm over a datum of zero. The datum represents a flat road profile, while negative values represent depressions/falls and positive values represent higher profiles/elevation rise than the datum. Such values are typical of class D and mine haul roads as seen in results presented by [44; 39]. [44] used experimental results to validate the random road profiles generated for several classes of roads. Experimental results showed strong agreement (R > 98%), demonstrating that random road profiles generated by ISO 8608 models produce reliable results. Since major surface defects are not considered in this study (they cannot be modelled using the ISO 8608 models), these profiles represent the surface roughness due to the road surface materials size distribution and construction and/or maintenance imperfections. Haul road surfaces are usually constructed with gravel or crushed waste rock, and graded regularly. The construction and maintenance processes inherently leave such undulations on the road surface.