Akademik Veri Yönetim Sistemi
JOURNAL OF THE FACULTY OF FORESTRY-ISTANBUL UNIVERSITY, cilt.67, sa.2, ss.201-209, 2017 (ESCI)
The construction of forest roads in Turkey follows a tender process conducted by the General Directorate of Forestry. The amount of work (i.e., excavation volume) is estimated for the approximate cost schedule required for the tender. Unexpected disputes have occurred during the process of finalizing the contracts because measurements are determined by a preliminary survey done prior to preparation of a detailed project proposal. The aim of this study was to compare the road construction data that was calculated during the tender process to the exact values that were obtained as a result of construction. A total of 34 forest roads constructed by Bolu Forest Regional Directorate between 2007 and 2014 were studied. Data were obtained from the tender dossiers to evaluate and compare the cost estimated for the tenders to the actual progress values (excavation quantities, excavation features and costs) of these projects. In addition, these roads have been evaluated according to forest road technical standards. The total length of the assessed roads was 73,879 m, the total costs were USD 977,138, and a total of 726,366 m(3) was excavated during the construction of these roads. Paired sample t-tests demonstrated a statistical difference between the tender cost estimates and the progress payment amounts, and between the estimated amounts of very hard rock excavation and the actual amounts of very hard rock excavation.