Kaboli, Alireza (2014) Cost and emissions analysis of earthmoving operations. PhD thesis, University of New South Wales, Australia.
Abstract
Traditionally, earthmoving and like operations have been organised based on a minimum unit cost criterion. However, there is an increasing awareness of the need to reduce carbon emissions due to their negative environmental impacts and the growing presence of carbon trading schemes and carbon taxes.This thesis examines earthmoving and like operations, including loader/excavator-truck and dozer-scraper operations, under two criteria – minimum emissions per production (unit emissions) and minimum cost per production (unit cost), and compares the optima for these criteria. Queuing theory is used for the theoretical evaluation of production for varying operation parameters. Variables considered in the analyses performed include equipment heterogeneity, payload, truck size, haul grade, and travel and load times. Truck dispatching is performed through the linear programming method and the effect of truck allocation on unit emissions and unit costs is established.It is demonstrated theoretically that the optima with respect to unit cost and unit emissions coincide in excavator/loader-truck operations, and this coincidence is invariant with changing operation parameters. To support the theoretical result, data from extensive field studies are used, including time and production measurements, and fuel burn data and its conversion to idling and non-idling emissions. Sensitivity analyses on the underlying parameters also support the conclusion. This thesis also shows that the optimum scraper load time for unit emissions may be the same or slightly less than that for unit cost depending on the scraper type and operation. Yet the optimum fleet size in terms of minimum unit emissions, is slightly higher than or the same as that in terms of minimum unit cost.It is concluded that the traditional way of undertaking earthmoving operations to give minimum unit costs will also result in minimum unit emissions. And that different configurations will lead to unnecessary emissions. In addition, the existing linearprogramming dispatching solution, based on minimising truck numbers and unit costs, accordingly impacts the environment the least in terms of emissions.It is important to know that the most environmentally friendly approach is also the most economical because this will reassure contractors who are concerned about environmental policy impacts on financial operations.
| Item Type: | Thesis (Doctoral) |
|---|---|
| Thesis advisor: | Carmichael, D |
| Uncontrolled Keywords: | optimal cost; earthmoving; optimal emissions; production; carbon emissions |
| Index terms: | earthmoving, presence, linear programming, truck dispatching, environmentally friendly, conversion, optimal cost, carbon emission, environmental policy, unit cost, unit emission, environmental impact, configuration, truck allocation, optimal emissions, field study, sensitivity analysis |
| Subjects: | bidding, construction operations, environmental science, public policy, climate science, environmental impact, transportation engineering, environmental hazards, transport systems, sustainable design, algorithms, research methods, manufacturing engineering, sustainability assessment, financial and cost management, systems engineering |
| Topics: | Digital Applications, Site Management, Research Practice, Cost Management, Governance, Supply Chain Management, Engineering Principles, Procurement, Sustainability |
| Descriptive scope: | 3 PCA |
N.B. Descriptive scope is a count of how many of the five facets of empirical research are indicated by the words used in title, abstract and keywords. It is not intended as a judgement on the research; merely a count of the kind of word we would expect to indicate Phenomenon, Concepts, Theoretical framing, Empirical techniques, Analytical techniques. If all five are present, then a code of “5 PCTEA” will indicate this. If you feel the coding for this record is questionable, we welcome discussion around the terms we matched or the way we categorized them. The facet you would expect may not be coded, or a facet may be coded inappropriately. This can also bear on a larger question, of which facets should be treated as defining in construction management research. Please get in touch, and we will look at it. More details here