• Journal of the Korean Institute of Landscape Architecture
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• v.50 no.4
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• pp.20-36
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• 2022

This study aims to provide basic data for high-quality street tree management by setting reasonable management items and appropriate unit prices by reviewing the adequacy of current street tree management. Currently, street tree management items, except for street tree pruning, use general landscape tree quantity per unit for the street tree management quantity per unit. KEPCO (Korea Electric Power Corporation) applied pruning items from standard electric production infrastructure and carried out the activities at an average unit price of 51% lower for heavy pruning and 39% lower for light pruning than the standard estimate. This was judged to be a level that could not maintain or increase the quality of street tree management. It was determined that an appropriate standard unit price for street tree management was necessary. To improve the quantity per unit for the proper management of street trees, it was necessary to review costs in the field. However, due to the absence of data on actual construction costs in the domestic landscape field, detailed items of the US RSMeans Building Construction Cost Data (RSMeans) were reviewed, and the actual construction costs were calculated by applying personal domestic expenses. As a result, the standard of the estimated unit showed a good ratio of 107% for heavy pruning of street tree pruning compared to the actual construction cost, but light pruning was underestimated with a 59% ratio. Shrub pruning was 82%, weeding was 92%, tree fertilization was 87%, and windbreak wall installation was 91% under-engineered. In addition, it was also confirmed that the watering by sprinkler trucks and chemical spraying were over-designed compared to the actual construction cost at the rates of 118% and 124%, respectively. Due to the specificity of the street trees, the increase in personal expenses and the input cost of equipment, such as road safety controls, were judged to be the main cause of the underestimation of items. Therefore, it is necessary to add items related to street trees and general landscape trees to the landscape maintenance items of the standard of the estimated unit.

• International conference on construction engineering and project management
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• 2009.05a
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• pp.685-691
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• 2009

Recently, public office building projects are being recognized by many construction engineers and researchers, as the critical projects in the construction industry. The project budgets have sometimes exceeded due to the lack of core knowledge, experiences, skills and experts concerned in cost planning and estimating in the pre-construction stage. It has been highlighted that planning and estimating effectively the cost of public office building projects as critical in the design stage. Within this context, some cost data books and systems, such as RSMeans cost data systems and Spon's price book, have been systematically developed and used by many construction cost managers and organizations in order to effectively estimate and use their project budgets. As a result of this research, a cost estimating model for finishes has been developed, considering the cost data used in public office building projects.

• International conference on construction engineering and project management
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• 2022.06a
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• pp.1194-1201
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• 2022

The existing literature has witnessed the importance of productivity assessment and deducing factors affecting it. However, yet many models have shown limitations in practical applications in actual construction sites for process planning due to uncertainty and lack of data. This research presents a productivity assessment and database generation framework using simulation and compares the results with RSMeans to derive appropriate equipment combinations alternatives for earthwork operations. Data of 15 different conditions was collected from 5 different construction sites. Prediction accuracy above 90% were achieved for the simulation models with average error rate of 7.4%. The construction productivity assessment framework presented in this study is expected to be highly applicable to operation planning for earthwork operations.

• Journal of Construction Engineering and Project Management
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• v.3 no.2
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• pp.58-65
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• 2013

Earthwork activities are typically performed by heavy duty diesel (HDD) construction equipment that consumes large quantities of diesel fuel use and emits large quantities of pollutants, including nitrogen oxides (NOx), particulate matters (PM), hydrocarbon (HC), carbon monoxide (CO), and carbon dioxide ($CO_2$). This paper presents the framework for a model that can be used to estimate the production rate, activity duration, total fuel use, and total pollutants emissions for earthwork activities. A case study and sensitivity analysis for an excavator performing excavations are presented. The tool is developed by combining the multiple linear regressions (MLR) approach for modeling the productivity with the EPA's NONROAD model. The excavator data from RSMeans Heavy Construction Data were selected to build the productivity model, and emission factors of all type of pollutants from NONROAD model were used to estimate the total fuel use and emissions. The MLR model for the productivity rate can explain 92% of the variability in the data. Based on the model, the fuel use and emissions of excavator increase as the trench depth increase, but as the bucket size increase, the fuel use and emissions decrease.