FAQ >> EARTHWORK EQUIPMENTS AND CONCRETING EQUIPMENTS IN CONSTRUCTION PROJECT

EARTHWORK EQUIPMENTS AND CONCRETING EQUIPMENTS IN CONSTRUCTION PROJECT

EARTHWORK EQUIPMENTS

A brief description of the equipments used In earthwork. The selection of earthmoving equipment is mainly dependent on the quantities of material to be moved, the available time to complete the work the job conditions, the prevailing soil types, the swell and compaction factors, etc. The job conditions include factors such as soil conditions, availability of loading and dumping area, accessibility of site, traffic flows and weather conditions at site (Alkass and Harris 1988). The type of supervision and the length of working day and shift work are also important for the selection of a particular type of earthmoving equipment. The decision to choose between a track-mounted earthmoving equipment and a wheel-mounted one depends to a large extent on the prevailing job conditions.

In order to plan the number of earthwork equipment needed, the planner first determines the following:

1. The suitable class of equipment for earthwork-for example, if the soil to be excavated is loose and marshy, and bulk excavation is involved In the project, one may opt for a dragline. The planner needs to be familiar with different classes of equipment used In earthwork and their suitability of working in different conditions.

2. The appropriate model ofequipment within that class-for a given class of equipment, be it an excavator, a scraper, or a dragline, manufacturers usually come up with different models with different performance characteristics such as payload ofbucket and speeds obtainable on different soil resistances. For example, draglines come in different capacities ranging from 0.38 m3 to 3.06 m3; scrapers in capacities ranging from 8 M3 to 50 m3 and so on.

3. The number of equipment needed for the project to carry out the given quantity-once the model with suitable payload capacity is decided, the only thing we need to determine is the cycle time.

4. The number of associated equipment required to support the main equipment

CONCRETING EQUIPMENTS

Selection of concreting equipment can be complicated and difficult. The decision will involve many issues that have to be analysed. The following factors mentioned by Alkass et al. (1993) are noteworthy:

  1. Site characteristics such as boundary conditions, equipment manoeuvre, provision of temporary roads. noise limitations and other restrictions
  2. Equipment availability-local availability of equipments, whether the contractor owns that equipment
  3. Continuity of operation
  4. Effect of permanent work
  5. Weather conditions
  6. Temporary works
  7. Time restrictions
  8. Concrete specifications

Concrete-mixing equipment selection will depend on factors such as the maximum and the total output required in a given time frame, the method of transporting the mixed concrete and the requirement of discharge height of the mixer. Concrete-placement equipment selection depends on factors such as the capacity of the vehicle, the output of the vehicle, the site characteristics, the weather conditions, the operator's efficiency, the rental costs, and the temporary haul roads. It is important that the system that guarantees minimum costs be selected.

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