제주도 내 회전교차로의 초기공사비 예측모델 개발

Abstract

Recently, there are many roundabouts installation works which are being ordered to provide convenient transportation to road users as well as to eliminate traffic accidents and traffic delays. As a result, even in Jeju since 2010, organizing and operating disruptive non-signalized intersections such as causing traffic accidents, increasing in cases of violations and unwanted signal latency at the intersection into roundabouts are preferentially performed. However a systematic study about prediction of construction is insufficient in the early stages of construction of roundabouts as well as the unit price and the criterion to predict the approximate cost of construction of roundabouts are not established. Therefore, in this study, it is aimed to suggest a calculation model for approximate construction cost to make roundabouts in the early stages of construction by considering the conditions of the construction site with roundabouts currently installed in Jeju. For this purpose, we collected, analyzed and utilized specifications such as reports, statements, drawings, quantity output document about 25 roundabouts whose design was made in Jeju from January 2012 to March 2013. Items which have high proportion of cost of construction were mainly analyzed on the basis of the results of cost analysis, and approximate cost estimation model was proposed through regression analysis based on regression equation or statistical analysis after deriving the items that affect cost. We derived cost by type such as excavations, drain hole, structure works, packing works, secondary work, key materials and cost per unit by inputting the quantity of the approximate quantity of construction of roundabouts to quantity values in the statement, and major influence factors by type derived through this. As a result of correlation analysis, it showed that there are significant relationships between packaging break and earthwork. For the drain hole, it showed that there are significant relationships with the extension of drainage. In the structure work, it showed a significant relationship between building a crown concrete and boulder stone, and the relationship with green belt border installation appeared in the case of package work. About secondary work, it showed a significant relationship with large signs installation, and carry-in materials and incidental expenses showed a significant relationship with subbase. As a result verified about derived regression equation, very high prediction accuracy was analyzed by showing the difference of 2.3%, 3.7%, 5.8% for error rate of the amount of the estimated and designed through a regression equation. In this study, regression equation of approximate construction cost was derived through regression analysis based on design data of 25 roundabouts construction in Jeju, and it was analyzed to have a high prediction accuracy. If it could based on more data in the future, the results are expected to be more reliable. Also regression model derived in this study for the approximate construction cost of roundabouts is expected to be utilized to reflect the budget of relevant construction cost and decision-making.