The earthmoving plant carrying out earthworks operations should be well balanced and compatible. The various machines should be of machined capacity and power rating and so machine should work below capacity. A perfect solution is rare and perhaps not entirely desirable as a slight excess of compaction and loading capacity is always useful- compaction because quality control of the fill is so critical and loading because if forces the pace, with any spare time being usefully employed in clearing the loading are and surrounding areas.
The selection of earthmoving plant may be simplified by deciding the ‘major role’ plant item first and then matching auxiliary (secondary role) plant to it. The ‘major role’ plant item is the one required to handle major earthworks activity . In most roadway excavation the key ‘major role’ item is usually the scraper or the loading unit.
Once the major role item has been selected from available earthmoving plant , and its movements decided, auxiliary (secondary role) plant to it. The ‘major role’ plant item is the one required to handle major earthworks activity . In most roadwork excavation the key ‘major role’ item is usually the scraper or the loading unit.
Once the major role item has been selected from available earthmoving plant, and its movements decided, auxiliary units can more easily be selected as the quantity of material to be handled and major role plant cycle times are known. For example, pusher requirements must be matched to the scraper cycle time; truck turnaround time must be matched to the loader cycle time and the rate of compaction must match the rate of delivery.
Of course, the above presupposes that the supporting units are of appropriate size and effectiveness, e.g.
• the pusher should preferably have greater power than the scrapper.
• the loader should fill a dump truck in a minimum number of uniform bucket loads.
• the roller(s) should suit the thickness of lift and material.
Because of earthmoving plant breakdowns, changing haulage leads and site conditions etc. continual monitoring and adjustment of operation are required to maintain, as far as possible, the balance of the plant fleet.
Close supervision and direction of operators is essential. Operators must know exactly what they are required to do. Often a short explanation of the reasons for a direction will assist in getting the right result.
Most items of construction or earthmoving plant usually require an operator’s full attention. Therefore sites to direct, control and guide operations.